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  • Elsevier  (5,804,698)
  • Oxford University Press  (428,974)
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  • 101
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    Oxford University Press
    Publication Date: 2024-04-02
    Description: Latinization is a strangely overlooked topic. Historians have noted it has been ‘taken for granted’ and viewed as an unremarkable by-product of ‘Romanization’, despite its central importance for understanding the Roman provincial world, its life and languages. This volume aims to fill the gap in our scholarship, along with its sister volumes, Latinization, Local Languages and Literacies in the Roman West and Languages and Communities in the Late-Roman and Post-Imperial Western Provinces, all outputs of the European Research Council-funded LatinNow project. Experts have been selected to create a multidisciplinary volume with a thematic approach to the vast subject, tackling administration, army, economy, law, mobility, religion (local and imperial religions and Christianity), social status, and urbanism. They situate the phenomena of Latinization, literacy, bi-, and multilingualism within local and broader social developments and draw together materials and arguments that have not before been coordinated in a single volume. The result is a comprehensive guide to the theme, which also offers original and more experimental work. The sociolinguistic, historical, and archaeological contributions reinforce, expand, and sometimes challenge our vision of Latinization and lay the foundations for future explorations.
    Keywords: army, economy, education, law, Latinization, mobility, religion, Roman western provinces, sociolinguistics, status, urbanism ; thema EDItEUR::N History and Archaeology::NH History::NHC Ancient history ; thema EDItEUR::N History and Archaeology::NH History::NHT History: specific events and topics::NHTB Social and cultural history ; thema EDItEUR::C Language and Linguistics::CF Linguistics::CFB Sociolinguistics
    Language: English
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  • 102
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    Oxford University Press
    Publication Date: 2024-04-07
    Description: Every day, two or three women die because of pregnancy or childbirth. Nearly 80% of these deaths are preventable. These outcomes disproportionately impact racialized populations, including Black and Indigenous women, who are two to three times more likely to die. The Practical Playbook III: Working Together to Improve Maternal Health is a guide for maternal health stakeholders (like researchers, community activists, providers, and advocates) offering practical tools and strategies to address inequities in maternal health services and outcomes. With contributions from more than 150 authors, each chapter offers a different strategy that stakeholders can apply to improve maternal health in their community. The 50 chapters are divided into six main sections: Section I, Introduction; Section II, Collaborations; Section III, Equity; Section IV, Data; Section V, Innovations; and Section VI, Systems and Scalability. The chapters focus on ways to save mothers by centering equity, collaborating with people with lived experience, building better data systems, piloting and expanding innovations, and leveraging resources to scale and sustain what works. Throughout the book, readers encounter stories from women and birthing people that bring the problems and solutions into better focus. The editors are committed to continuing to share information about initiatives that are moving the needle through our online platforms.
    Keywords: Maternal Mortality, Maternal Morbidity Racial Disparities, maternal health equity, maternal health stakeholders, playbook, Maternal Health Data, Collaboration, Innovation, Sustainability ; thema EDItEUR::M Medicine and Nursing::MB Medicine: general issues::MBN Public health and preventive medicine ; thema EDItEUR::M Medicine and Nursing::MK Medical specialties, branches of medicine::MKC Gynaecology and obstetrics ; thema EDItEUR::M Medicine and Nursing::MB Medicine: general issues::MBN Public health and preventive medicine::MBNS Epidemiology and Medical statistics
    Language: English
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  • 103
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    Oxford University Press
    Publication Date: 2024-03-19
    Description: Comparing the Worth of the While in Fiji and Finland presents comparative case studies of clock time from Fiji and Finland in order to ask what other values is time capable of expressing besides monetary worth – what “else” can time be besides money? Time is a highly particular vehicle for different considerations of what is good or important, but it is also one which is deployed at different settings with surprisingly little consideration for the specificity of this particular a value form. This book looks into the different ways in which time is deployed in value projects in Fiji and Finland, not just to point out the various possible ways of allocating value to time, but to show that European clock-time, just like its Oceanic counterparts, requires a great deal of conceptual work to make it serve as vehicle of valuation. The cases analysed in the book range from considerations of rank and conspicuous leisure in Fiji to Finnish timebanking, taxation, and university auditing.
    Keywords: Fiji, Finland, time, value, anthropology ; bic Book Industry Communication::J Society & social sciences::JH Sociology & anthropology::JHM Anthropology::JHMC Social & cultural anthropology, ethnography ; bic Book Industry Communication::P Mathematics & science::PG Astronomy, space & time::PGZ Time (chronology), time systems & standards ; bic Book Industry Communication::J Society & social sciences::JH Sociology & anthropology::JHM Anthropology
    Language: English
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  • 104
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    Oxford University Press
    Publication Date: 2024-04-07
    Description: The Inter-American Human Rights System (IAHRS) fosters structural transformations throughout the Americas. This collection of analyses builds upon the studies on Ius Constitutionale Commune en América Latina and Latin American transformative constitutionalism to map out both the ground-level human rights impact of the IAHRS and the institutional characteristics that have enabled such fundamental changes in social reality. The volume starts with essays framing the concept and context of IAHRS impact. Then it navigates thematic analyses on specific rights and types of violations that are front and center to the protection of human rights in Latin America. The concluding essays explore whether and how it is possible to optimize the actions of the Inter-American System, indicating possible paths to increase positive human rights impact. The editors contend that the IAHRS victim-centric approach, community of practice, and openness to institutional reinvention have enabled it to create a virtuous cycle that catalyzes human rights in the Americas, furthering democracy and the Rule of Law throughout the continent.
    Keywords: Inter-American System, impact, human rights, Transformative Constitutionalism, Latin America ; thema EDItEUR::L Law::LB International law::LBB Public international law::LBBZ Public international law: criminal law ; thema EDItEUR::1 Place qualifiers::1K The Americas::1KL Latin America – Mexico, Central America, South America ; thema EDItEUR::L Law::LB International law::LBB Public international law::LBBR Public international law: human rights
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  • 105
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    Oxford University Press
    Publication Date: 2024-04-14
    Description: Computing systems are everywhere today. Even the brain is thought to be a sort of computing system. But what does it mean to say that a given organ or system computes? What is it about laptops, smartphones, and nervous systems that they are deemed to compute, and why does it seldom occur to us to describe stomachs, hurricanes, rocks, or chairs that way? The book provides an extended argument for the semantic view of computation, which states that semantic properties are involved in the nature of computing systems. Laptops, smartphones, and nervous systems compute because they are accompanied by representations. Stomachs, hurricanes, and rocks, for instance, which do not have semantic properties, do not compute. The first part of the book argues that the linkage between the mathematical theory of computability and the notion of physical computation is weak. Theoretical notions such as algorithms, effective procedure, program, and automaton play only a minor role in identifying physical computation. The second part of the book reviews three influential accounts of physical computation and argues that while none of these accounts is satisfactory, each of them highlights certain key features of physical computation. The final part of the book develops and argues for a semantic account of physical computation and offers a characterization of computational explanations.
    Keywords: Metaphysics; Philosophy of Mathematics & Logic; Philosophy of Computational Science; Philosophy of Mathematics & Logic ; thema EDItEUR::U Computing and Information Technology::UY Computer science ; thema EDItEUR::U Computing and Information Technology::UY Computer science
    Language: English
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  • 106
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    Oxford University Press
    Publication Date: 2024-03-29
    Description: Pakistan would desperately like to produce enough electricity, but it usually doesn’t. This is the rare issue on which government and private sector can unite, and it is the cause of suffering for rich and poor alike across the entirety of the country. Despite prioritization by successive governments, targeted reforms shaped by international development actors, and featuring prominently in Chinese Belt and Road Investments, the Pakistani power sector still stifles economic and social life across the country. This book explores state capacity in Pakistan by following the material infrastructure of electricity across the provinces and down into cities and homes. It argues that the national challenges of budgetary constraints and power shortages directly result from conscious strategic decisions that are integral to Pakistan’s infrastructural state. Electricity shortages are one of the many poor governance outcomes characteristic of low- and middle-income countries. Standard development thinking points to an absence of institutions in comparison with an idealized and distant other country, with governance reform programs formulated accordingly. However, an orientation toward what Pakistan is not takes us away from how it actually functions and to whose benefit. Electricity governance in Pakistan reinforces relations of power between provinces and the federal center, contributes to the marginalization of subordinate groups in the city, and orients citizens toward a patronage-based relationship with the state through encounters with street-level bureaucrats. Looking through the lens of the electrical power sector reveals how Pakistan works, and for whom.
    Keywords: state capacity, infrastructure, electricity, Pakistan, urban, ethnography, institutions, political economy, development, China–Pakistan Economic Corridor ; thema EDItEUR::J Society and Social Sciences::JP Politics and government::JPB Comparative politics ; thema EDItEUR::G Reference, Information and Interdisciplinary subjects::GT Interdisciplinary studies::GTP Development studies ; thema EDItEUR::J Society and Social Sciences::JP Politics and government::JPQ Central / national / federal government::JPQB Central / national / federal government policies
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  • 107
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    Oxford University Press
    Publication Date: 2024-04-03
    Description: The case for a modern democratic humane socialism typically has two parts. The first is that capitalism is bad, at or least not very good. In reaching this conclusion, most have either analyzed a theoretical ideal-type of capitalism or used a single country, often the United States, as a stand-in for capitalism. To fully and fairly assess democratic socialism’s desirability, we need to compare it to the best version of capitalism that humans have devised: social democratic capitalism, or what is often called the Nordic model. Each chapter in this book examines one of the things that we should want in a good society, that contemporary democratic socialists typically say they want, and that socialism might, conceivably, improve our ability to achieve: an end to poverty in rich countries, an end to poverty everywhere, more jobs, decent jobs, faster economic growth, inclusive growth, more public goods and services, affordable healthcare for all, helpful finance, truly democratic politics, economic democracy, less economic inequality, gender and racial equality, more community, and a livable planet. The book offers a close look at the evidence about how capitalist economies have performed on these outcomes, with particular attention to the performance of social democratic capitalism. The second part of the case for democratic socialism is the notion that it would be an improvement. For each of these outcomes, the book considers what, if anything, we can conclude about whether democratic socialism would do better than social democratic capitalism.
    Keywords: capitalism, socialism, Nordic model, poverty, employment, democracy, equality, inclusion, community ; thema EDItEUR::J Society and Social Sciences::JP Politics and government::JPB Comparative politics ; thema EDItEUR::J Society and Social Sciences::JP Politics and government::JPS International relations::JPSL Geopolitics
    Language: English
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  • 108
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    Oxford University Press
    Publication Date: 2024-04-08
    Description: This book is about mental imagery and the important work it does in our mental life. It plays a crucial role in the vast majority of our perceptual episodes. It also helps us understand many of the most puzzling features of perception (like the way it is influenced in a top-down manner and the way different sense modalities interact). But mental imagery also plays a very important role in emotions, action execution, and even in our desires. In sum, there are very few mental phenomena that mental imagery doesn’t show up in—in some way or other. The hope is that if we understand what mental imagery is, how it works and how it is related to other mental phenomena, we can make real progress on a number of important questions about the mind. This book aims at an interdisciplinary audience. As it aims to combine philosophy, psychology, and neuroscience to understand mental imagery, I have not presupposed any prior knowledge in any of these disciplines. As a result, readers with no background in any of these disciplines can also follow the arguments.
    Keywords: mental imagery, imagination, perception, philosophy, psychology, neuroscience ; bic Book Industry Communication::H Humanities::HP Philosophy::HPM Philosophy of mind ; bic Book Industry Communication::H Humanities::HP Philosophy::HPN Philosophy: aesthetics ; bic Book Industry Communication::J Society & social sciences::JM Psychology::JMR Cognition & cognitive psychology::JMRP Perception ; bic Book Industry Communication::H Humanities::HP Philosophy ; bic Book Industry Communication::J Society & social sciences::JM Psychology::JMR Cognition & cognitive psychology ; bic Book Industry Communication::P Mathematics & science::PS Biology, life sciences::PSA Life sciences: general issues::PSAN Neurosciences ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy::QDT Topics in philosophy::QDTM Philosophy of mind ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy::QDT Topics in philosophy::QDTN Philosophy: aesthetics ; thema EDItEUR::J Society and Social Sciences::JM Psychology::JMR Cognition and cognitive psychology ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences::PSA Life sciences: general issues::PSAN Neurosciences
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  • 109
    Publication Date: 2023-12-06
    Description: Highlights: • Inhibitory potential of eelgrass microbiome against aquatic and fecal pathogens • Isolation of epiphytes and endophytes associated with eelgrass leaves and roots • Particularly leaf epibiotic bacteria exhibit significant antimicrobial activity. • Rich secondary metabolite composition by untargeted metabolomics • Potential involvement of eelgrass microbiome in seagrass ecosystem services Seagrass meadows provide crucial ecosystem services for coastal environments and were shown to reduce the abundance of waterborne pathogens linked to infections in humans and marine organisms in their vicinity. Among potential drivers, seagrass phenolics released into seawater have been linked to pathogen suppression, but the potential involvement of the seagrass microbiome has not been investigated. We hypothesized that the microbiome of the eelgrass Zostera marina, especially the leaf epiphytes that are at direct interface between the seagrass host and the surrounding seawater, inhibit waterborne pathogens thereby contributing to their removal. Using a culture-dependent approach, we isolated 88 bacteria and fungi associated with the surfaces and inner tissues of the eelgrass leaves (healthy and decaying) and the roots. We assessed the antibiotic activity of microbial extracts against a large panel of common aquatic, human (fecal) and plant pathogens, and mined the metabolome of the most active extracts. The healthy leaf epibiotic bacteria, particularly Streptomyces sp. strain 131, displayed broad-spectrum antibiotic activity superior to some control drugs. Gram-negative bacteria abundant on healthy leaf surfaces, and few endosphere-associated bacteria and fungi also displayed remarkable activities. UPLC-MS/MS-based untargeted metabolomics analyses showed rich specialized metabolite repertoires with low annotation rates, indicating the presence of many undescribed antimicrobials in the extracts. This study contributes to our understanding on microbial and chemical ecology of seagrasses, implying potential involvement of the seagrass microbiome in suppression of pathogens in seawater. Such effect is beneficial for the health of ocean and human, especially in the context of climate change that is expected to exacerbate all infectious diseases. It may also assist future seagrass conservation and management strategies.
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  • 110
    Publication Date: 2023-11-21
    Description: The world's forests store large amounts of carbon (C), and growing forests can reduce atmospheric CO2 by storing C in their biomass. This has provided the impetus for world-wide tree planting initiatives to offset fossil-fuel emissions. However, forests interact with their environment in complex and multifaceted ways that must be considered for a balanced assessment of the value of planting trees. First, one needs to consider the potential reversibility of C sequestration in trees through either harvesting or tree death from natural factors. If carbon storage is only temporary, future temperatures will actually be higher than without tree plantings, but cumulative warming will be reduced, contributing both positively and negatively to future climate-change impacts. Alternatively, forests could be used for bioenergy or wood products to replace fossil-fuel use which would obviate the need to consider the possible reversibility of any benefits. Forests also affect the Earth's energy balance through either absorbing or reflecting incoming solar radiation. As forests generally absorb more incoming radiation than bare ground or grasslands, this constitutes an important warming effect that substantially reduces the benefit of C storage, especially in snow-covered regions. Forests also affect other local ecosystem services, such as conserving biodiversity, modifying water and nutrient cycles, and preventing erosion that could be either beneficial or harmful depending on specific circumstances. Considering all these factors, tree plantings may be beneficial or detrimental for mitigating climate-change impacts, but the range of possibilities makes generalisations difficult. Their net benefit depends on many factors that differ between specific circumstances. One can, therefore, neither uncritically endorse tree planting everywhere, nor condemn it as counter-productive. Our aim is to provide key information to enable appropriate assessments to be made under specific circumstances. We conclude our discussion by providing a step-by-step guide for assessing the merit of tree plantings under specific circumstances.
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  • 111
    Publication Date: 2023-11-29
    Description: Seaweed farming contributes substantial amounts of organic carbon to the ocean, part of which can be locked for a long term in the ocean and perform the function of ocean carbon sequestration, and the other part can be converted into inorganic carbon through microbial mineralization and aerobic respiration, affecting the pCO2, pHT and dissolved oxygen of seawater. It is generally believed that seaweed farming will cause the seawater to become a sink of CO2 due to carbon fixation by macroalgal photosynthesis. However, little attention has been paid to the fact that seaweed farming environment may sometimes become a source rather than a sink of CO2. Here, through in-situ mesocosm cultivation experiments and eight field investigations covering different kelp growth stages in an intensive farming area in China, we found that compared with the surrounding seawater without kelps, the seawater at the fast-growth stage of kelp was a sink of CO2 (pCO2 decreased by 17−73 μatm), but became a source of CO2 at the aging stage of kelp (pCO2 increased by 20−37 μatm). Concurrently, seawater pHT experienced a transition from increase (by 0.02−0.08) to decline (by 0.03−0.04). In-situ mesocosm cultivation experiments showed that the positive environmental effects (i.e., pCO2 decrease and pHT increase) induced by kelps at the early growth stage could be offset within only 3 days at the late-growth and aging stages. The release of dissolved organic carbon by kelps at the late growth stage increased significantly, supporting the enhancement in microbial abundance and respiration, which was manifested by the remarkable decrease in seawater dissolved oxygen, ultimately leading to CO2 release exceeding photosynthetic CO2 absorption. This study suggests that mature farmed kelps should be harvested in time to best utilize their carbon sink function and environmental benefits, which has guiding significance for the rational management of seaweed farming.
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  • 112
    Publication Date: 2023-12-18
    Description: Total alkalinity (TA) is an important variable of the ocean carbonate system. In coastal oceans, carbonate system dynamics are controlled by a range of processes including photosynthesis and respiration, calcification, mixing of water masses, continental inputs, temperature changes, and seasonal upwelling. Assessments of diel, seasonal and interannual variations in TA are required to understand the carbon cycle in coastal oceans. However, our understanding of these variations remains underdeveloped due to limitations in observational techniques. Autonomous TA measurements are therefore required. In this study, an in situ TA analyzer (ISA-TA) based on a single-point titration with spectrophotometric pH detection was deployed in Tong'an Bay, Xiamen, China, over a five-month period in 2021 to determine diel and seasonal TA variations. The TA observations were combined with an artificial neural network (ANN) model to construct TA prediction models for this area. This provided a simple method to investigate TA variations in this region and was applied to predict surface water TA between March and April 2021. The in situ TA observations showed that TA values in Tong'an Bay varied within a range from 1931 to 2294 μmol kg−1 over the study period, with low TA in late winter, early summer and late summer, and high TA in early winter. The TA variations in late summer and early winter were mainly controlled by mixing of water bodies. The diel variations of TA were greatly determined by tides, with a diel amplitude of 9 to 247 μmol kg−1. The ANN model used temperature, salinity, chlorophyll, and dissolved oxygen to estimate TA, with a root-mean-square error (RMSE) of ∼14 μmol kg−1, with salinity as the input variable with the greatest weight. The approach of combining ISA-TA observations with an ANN model can be extended to study the carbonate system in other coastal regions.
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  • 113
    Publication Date: 2024-01-17
    Description: Highlights • SPM concentration and organic fractions are analyzed in coastal-offshore gradients • Diagnostic model of SPM allows separating fresh, labile from less reactive PON • Analysis of PON fractions reveals a characteristic area, the transition zone • There, particle settling is enhanced, fostering their transport back to the coast, which controls the fate of organic matter • The transition zone is generally confined to water depths below 20 m Abstract Identifying the mechanisms that contribute to the variability of suspended particulate matter concentrations in coastal areas is important but difficult, especially due to the complexity of physical and biogeochemical interactions involved. Our study addresses this complexity and investigates changes in the horizontal spread and composition of particles, focusing on cross-coastal gradients in the southern North Sea and the English Channel. A semi-empirical model is applied on in situ data of SPM and its organic fraction to resolve the relationship between organic and inorganic suspended particles. The derived equations are applied onto remote sensing products of SPM concentration, which provide monthly synoptic maps of particulate organic matter concentrations (here, particulate organic nitrogen) at the surface together with their labile and less reactive fractions. Comparing these fractions of particulate organic matter reveals their characteristic features along the coastal-offshore gradient, with an area of increased settling rate for particles generally observed between 5 and 30 km from the coast. We identify this area as the transition zone between coastal and offshore waters with respect to particle dynamics. Presumably, in that area, the turbulence range and particle composition favor particle settling, while hydrodynamic processes tend to transport particles of the seabed back towards the coast. Bathymetry plays an important role in controlling the range of turbulent dissipation energy values in the water column, and we observe that the transition zone in the southern North Sea is generally confined to water depths below 20 m. Seasonal variations in suspended particle dynamics are linked to biological processes enhancing particle flocculation, which do not affect the location of the transition zone. We identify the criteria that allow a transition zone and discuss the cases where it is not observed in the domain. The impact of these particle dynamics on coastal carbon storage and export is discussed.
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  • 114
    Publication Date: 2024-01-30
    Description: Coastal German waters contain about 1.6 million tons of dumped munition, mostly left after World Wars. This study investigated the benthic macrofauna around the 'Kolberger Heide' munition dumpsite (Baltic Sea). A total of 93 macrofauna grab samples were obtained in the proximity of the munition dumpsite and in reference areas. Environmental variables analysed included the latitude/longitude, depth, terrain ruggedness, sediment grainsize distribution, TNT concentration in the bottom water and distance to the centre of munition dumpsite. The overall abundance, biomass and diversity varied among these groups, though demonstrated no clear differences regarding the proximity to munition and modelled near-bottom dissolved TNT. Among individual taxa, however, a total of 16 species demonstrated significant correlation with TNT concentration. Moreover, TNT may serve as a predictor for the distribution of three species: molluscs Retusa truncatula, Varicorbula gibba and polychaete Spio goniocephala. Possible reasons for the species distribution including their biological traits are discussed.
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  • 115
    Publication Date: 2024-01-30
    Description: Highlights • Global primitive arc lavas (Mg# ≥60) display notable δ49/47Ti heterogeneity. • Residual rutile imposes high δ49/47Ti of 0.24 ± 0.06 ‰ on hydrous, silicic slab melts. • Primitive Aleutian rhyodacites have the same δ49/47Ti as predicted for slab melts. • A variably diluted signature of slab melts is found in all eight subduction zones. • A slab melt component is required to generate silicic primitive arc lavas. Abstract It is still a matter of intense debate to what extent partial melting of the subducting slab contributes to arc magmatism in modern subduction zones. In particular, it is difficult to differentiate between silicate melts formed by partial melting of the slab, and aqueous fluids released during subsolidus dehydration as the main medium for slab-to-mantle wedge mass transfer. Here we use δ49/47Ti (the deviation in 49Ti/47Ti of a sample to the OL-Ti reference material) as a robust geochemical tracer of slab melting. Hydrous partial melting of subducted oceanic crust and the superjacent sedimentary layer produces silicic melts in equilibrium with residual rutile. Modelling shows that such silicic slab melts have notably higher δ49/47Ti (+0.24 ± 0.06 ‰) than their protolith due to the strong preference of rutile for the lighter isotopes of Ti. In contrast, even highly saline fluids cannot carry Ti from the slab and hence hydrous peridotite partial melts have δ49/47Ti similar to mid-ocean ridge basalts (MORB; ca. 0 ‰). Primitive (Mg# ≥60) arc lavas from eight subduction zones that are unaffected by fractional crystallisation of Fe-Ti oxides show a more than tenfold larger variation in δ49/47Ti than found in MORB. In particular, primitive arc lavas display a striking correlation between SiO2 content and δ49/47Ti that ranges from island arc basalts overlapping with MORB, to primitive rhyodacites with δ49/47Ti up to 0.26 ‰ erupted in the western Aleutian arc. The elevated δ49/47Ti of these primitive arc lavas provides conclusive evidence for partial melts of the slab as a key medium for mass transfer in subduction zones. The Aleutian rhyodacites represent a rare example of slab melts that have traversed the mantle wedge with minimal modification. More commonly, slab melts interact with the mantle wedge to form an array of primary arc magmas that are a blend of slab- and peridotite-derived melt. We identify primitive arc lavas with a clearly resolvable slab melt signature in all eight subduction zone localities, confirming that slab melting is prevalent in modern subduction zones.
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  • 116
    Publication Date: 2024-01-30
    Description: Highlights • An event-scale, complete lithostratigraphic column for the Miocene BFVA was created through extensive field volcanology. • Field volcanology was supplemented by volcanic glass geochemistry to separate the eruptions. • An example is presented how to undertake lithostratigraphy-based classification in poorly preserved, deeply eroded volcanic terrains. • In the ancient BFVA landscape, sea cover during eruptions and terrestrial deposition is evident. Abstract This study documents the volcanic evolution of the Miocene silicic Bükk Foreland Volcanic Area (BFVA), Northern Hungary (Central Europe) at an event-scale. The BFVA is a deeply eroded and dissected volcanic field dominated by multiple, several 10-m thick, valley-filling silicic ignimbrite units, which are chemically and texturally very similar to each other. Hence, establishing lateral correlation is a real challenge due to the sporadic and small-scale outcrops and lack of stratotypes. Detailed field observations allowed us to identify eleven lithological members including fourteen eruption events and establish a nearly complete lithostratigraphic correlation between fifteen outcrops across the BFVA. Primary pyroclastic material of each member was sampled, and volcanic glass was geochemically analyzed for major and trace element composition. The geochemical results confirm the field-based classification of the members and enable the correlation of distinct outcrops. The major and trace element composition of the glassy pyroclasts of each member of the BFVA served as basis to create a field-wide chemical reference database for regional correlational studies. Here, a new lithostratigraphic classification scheme (consisting of one lithostratigraphic formation and eleven members) is presented, which reflects the challenges unraveling the stratigraphy of ancient volcanic terrains. The field-based event-scale lithostratigraphy of the BFVA suggests a wet, partly sea-covered depositional environment in the close vicinity of the eruption centers providing favorable conditions to ‘fuel’ silicic explosive phreatomagmatism. On the contrary, paleosol horizons formed after almost each major eruption event or sequence suggests an overall near-coast terrestrial environment for the BFVA, where the emplacement of the pyroclastic material occurred.
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  • 117
    Publication Date: 2024-02-01
    Description: Regime shifts in the diatom–dinoflagellate composition have occurred in the Baltic Sea (BS) and Bohai Sea (BHS) under eutrophication and have affected the entire coastal ecosystem, damaging the regulatory, provisioning, cultural, and supporting service functions of marine ecosystems. Therefore, finding a solution to restore the balance of phytoplankton community composition and mitigate eutrophication is of utmost importance. In this study, the Driver (per capita gross domestic product)-Pressure (terrestrial inputs)-State (seawater environmental parameters)-Impact (proportions of diatoms and dinoflagellates)-Response (eutrophication governance projects) framework served as a guide for our analysis of the causal relationship among various environmental components in the coastal system. The relevant data in BS and BHS spanning from the 1950s to the 2010s were collected and used to construct a diatom–dinoflagellate composition single index, which allowed us to identify the shifts in regimes (mutation points and phases) of the diatom–dinoflagellate composition and environmental factors using sequential t-test analysis. We also identified key environmental factors that moderated the diatom–dinoflagellate composition using redundancy analysis and analyzed the partial effects of the main environmental factors on the diatom–dinoflagellate composition using a generalized additive model. Finally, the regulation of the eutrophication governance investment on diatom–dinoflagellate composition was investigated. We found that (1) BS is a “time machine,” with coastal eutrophication governance and regime shift of diatom–dinoflagellate composition and environmental factors two decades earlier than that in BHS; (2) in BS, the key moderation factor of diatom proportion is SiO3-Si and those of dinoflagellates are sea surface salinity and N:P ratio; in BHS, the key moderation factors of diatom proportion are PO4-P and Si:N ratio and those of dinoflagellate are dissolved inorganic nitrogen and N:P and Si:P ratios; (3) it is projected that BHS will enter its recovery phase from eutrophication after mid-2020s. In summary, the N/P/Si stoichiometric relationships should be given greater consideration, with the exception of the “dose-response” relationship in both sea areas. Our results indicate an urgent need for an improved mechanistic understanding of how phytoplankton biodiversity changes in response to changes in nutrient load and how we should ultimately deal with the challenges that arise.
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  • 118
    Publication Date: 2024-02-05
    Description: A La Niña condition in the equatorial Pacific began in the early summer of 2020 and has lasted more than two and a half years (referred to as the 2020 La Niña hereafter). Predicting its temporal evolution had attracted a lot of attention. Considering the possible phase-locked impact of the 11-year solar cycle on the tropical Pacific variability, in this study the authors present the possible modulations by the solar cycle 25 (SC25) started from December 2019, on the future temporal evolution of the 2020 La Niña. Based on statistical features of historical solar cycles, the authors propose three possible scenarios of the timing of the SC25 maximum year and discuss its possible impacts on the temporal evolution of the 2020 La Niña in the next two years. The ongoing ascending phase of SC25 dampens the development of a super El Niño condition to some extent in 2023.
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  • 119
    Publication Date: 2024-02-12
    Description: Highlights: • Change in sea urchin species composition from RBC and NRBC habitats. • Sand coverage is an important factor that influences the sea urchin species composition. • The relationship between sea urchins and their habitat is species-specific. Sea urchins are important components of marine ecosystems and can act as bioindicators, reflecting the health of reefs. The spatial patterns of sea urchins are largely shaped by the type of habitat. In Hong Kong, coral communities are divided into two distinct types: reef -building coral habitats and non -reef -building coral habitats. In summer 2020, a qualitative survey was conducted using SCUBA at 56 sites across eastern and western waters, recording a total of 11 species from 6 families of sea urchins. Out of these 56 sites, 14 were selected for a quantitative survey to investigate the relationship between sea urchin assemblages and the two types of coral habitat. We found that the species composition of sea urchins differed significantly between the two habitats, and the presence of sand was a critical factor influencing the species composition of sea urchins. Sand coverage had a positive effect on Salmasic sphaeroides abundance but a negative effect on the abundance of Diadema setosum and Heliocidaris crassispina. The distribution of sea urchins across different degrees of sand coverage may be associated with food availability or species -specific adaptive behaviour, likely due to niche preferences.
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  • 120
    Publication Date: 2024-02-12
    Description: Highlights • East Asian climate evolution was dependent on the latitude of the proto-Tibetan Plateau in the deep past; • Global warming induced wetting at mid-latitude East Asian in the mid-Cretaceous; • The proto-Tibetan Plateau uplift led to drying in the subtropical East Asian in the mid-Cretaceous. Abstract Sedimentary records indicate that subtropical and mid-latitude East Asia exhibited considerable drying and wetting, respectively, during the mid-Cretaceous, which is considered to be relevant to much higher atmospheric carbon dioxide (pCO2) concentrations and/or proto-Tibetan Plateau (proto-TP) uplift. In order to explore and compare their roles on the East Asian climate evolution, we conducted simulations of the mid-Cretaceous climate system with different atmospheric pCO2 levels and varying topographies. The results show that both factors had significant influences on the East Asian climate. As the increase in atmospheric pCO2 levels from ∼560–1120 ppmv to ∼1120–2240 ppmv, the precipitation increases considerably over mid-latitude East Asia, but only small changes in the subtropical portion of East Asia occur. Simultaneously, the effects of the proto-TP uplift are opposite to those of global warming trend during that period. Generally, it leads to a precipitation decrease over subtropical East Asia, but rather minor changes over mid-latitude East Asia. These changes are qualitatively consistent with the deduction based on the geological records, but the magnitudes of the modeled precipitation changes are relatively smaller. Therefore, we can conclude that the subtropical East Asian drying during the mid-Cretaceous can be partly explained by the proto-TP uplift, while the mid-latitude East Asian wetting was partly due to global warming. However, additional factor(s) also played a significant role in the East Asian climate evolution during the mid-Cretaceous.
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  • 121
    Publication Date: 2024-02-12
    Description: Carbon dioxide removal (CDR) – the creation, enhancement, and upscaling of carbon sinks – has become a pillar of national and corporate commitments towards Net Zero emissions, as well as pathways towards realizing the Paris Agreement's ambitious temperature targets. In this perspective, we explore CDR as an emerging issue of Earth System Governance (ESG). We draw on the results of a workshop at the 2022 Earth System Governance conference that mapped a range of actors, activities, and issues relevant to carbon removal, and refined them into research questions spanning four intersecting areas: modeling and systems assessment, societal appraisal, policy, and innovation and industry. We filter these questions through the five lenses of the ESG framework and highlight several key ‘cross-cutting’ issues that could form the basis of an integrated ESG research agenda on CDR.
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  • 122
    Publication Date: 2024-02-12
    Description: Highlights • Cu complexation was measured for the first time in the Fram Strait region. • Cu-binding ligand concentrations and binding strength varied longitudinally in the Fram Strait. • More than 99 % of dCu was organically complexed by strong ligands. • On the Greenland shelf the Transpolar Drift and the coastal processes were the main sources of Cu ligands. Abstract The Fram Strait represents the major gateway of Arctic Ocean waters towards the Nordic Seas and North Atlantic Ocean and is a key region to study the impact of climate change on biogeochemical cycles. In the region, information about trace metal speciation, such as copper, is scarce. This manuscript presents the concentrations and conditional stability constants of copper-binding ligands (LCu and log KcondCu2+L) in the water column of Fram Strait and the Greenland shelf (GEOTRACES cruise GN05). Cu-binding ligands were analysed by Competitive Ligand Exchange-Adsorptive Cathodic Stripping Voltammetry (CLE-ACSV) using salicylaldoxime (SA) as competitive ligand. Based on water masses and the hydrodynamic influences, three provinces were considered (coast, shelf, and Fram Strait) and differences were observed between regions and water masses. The strongest variability was observed in surface waters, with increasing LCu concentrations (mean values: Fram Strait = 2.6 ± 1.0 nM; shelf = 5.2 ± 1.3 nM; coast = 6.4 ± 0.8 nM) and decreasing log KcondCu2+L values (mean values: Fram Strait = 15.7 ± 0.3; shelf = 15.2 ± 0.3; coast = 14.8 ± 0.3) towards the west. The surface LCu concentrations obtained above the Greenland shelf indicate a supply from the coastal environment to the Polar Surface Water (PSW) which is an addition to the ligand exported from the central Arctic to Fram Strait. The significant differences (in terms of LCu and log KcondCu2+L) between shelf and coastal samples were explained considering the processes which modify ligand concentrations and binding strengths, such as biological activity in sea-ice, phytoplankton bloom in surface waters, bacterial degradation, and meltwater discharge from 79NG glacier terminus. Overall, the ligand concentration exceeded those of dissolved Cu (dCu) and kept the free copper (Cu2+) concentrations at femtomolar levels (0.13–21.13 fM). This indicates that Cu2+ toxicity limits were not reached and dCu levels were stabilized in surface waters by organic complexes, which favoured its transport to the Nordic Seas and North Atlantic Ocean and the development of microorganism.
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  • 123
    Publication Date: 2024-02-14
    Description: The increasing global demand for seafood, coupled with the limitations of current fish stocks and aquaculture practices, requires the development of sustainable aquaculture solutions. In this context, this study explores the potential of a novel cage technology - Flow2Vortex - for the cultivation of jellyfish, a low-trophic-level organism with increasing market demand. The unique cage design creates a laminar and circular water flow, providing optimal conditions for cultivating fragile planktonic species. Indoor experiments demonstrated the successful growth of jellyfish in the cage, with growth rates of up to 11.6% per day. In addition, field tests in open waters confirmed the cage's ability to maintain a diffuse and controlled flow inside, even under strong external currents. The cage also maintained significantly higher zooplankton concentrations than the surrounding environment, offering a consistent food source for the cultivated jellyfish. These findings highlight the potential of the Flow2Vortex cage for scalable indoor and outdoor cultivation of low-trophic-level organisms, such as jellyfish, contributing to the diversification and sustainability of aquaculture practices.
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  • 124
  • 125
    Publication Date: 2024-02-22
    Description: Highlights • More diverse non-native taxa generally include more economically costly species. • Chordates, nematodes and pathogens are among significantly over-represented taxa. • Monetary cost magnitude links positively to numbers of costly invasive species. • Costs are biased towards a few ‘hyper-costly’ invasive species groups. • Future invasion rates will continue to harbour new economically costly species. Abstract A dominant syndrome of the Anthropocene is the rapid worldwide spread of invasive species with devastating environmental and socio-economic impacts. However, the dynamics underlying the impacts of biological invasions remain contested. A hypothesis posits that the richness of impactful invasive species increases proportionally with the richness of non-native species more generally. A competing hypothesis suggests that certain species features disproportionately enhance the chances of non-native species becoming impactful, causing invasive species to arise disproportionately relative to the numbers of non-native species. We test whether invasive species with reported monetary costs reflect global numbers of established non-native species among phyla, classes, and families. Our results reveal that numbers of invasive species with economic costs largely reflect non-native species richness among taxa (i.e., in 96 % of families). However, a few costly taxa were over- and under-represented, and their composition differed among environments and regions. Chordates, nematodes, and pathogenic groups tended to be the most over-represented phyla with reported monetary costs, with mammals, insects, fungi, roundworms, and medically-important microorganisms being over-represented classes. Numbers of costly invasive species increased significantly with non-native richness per taxon, while monetary cost magnitudes at the family level were also significantly related to costly invasive species richness. Costs were biased towards a few ‘hyper-costly’ taxa (such as termites, mosquitoes, cats, weevils, rodents, ants, and asters). Ordination analysis revealed significant dissimilarity between non-native and costly invasive taxon assemblages. These results highlight taxonomic groups which harbour disproportionately high numbers of costly invasive species and monetary cost magnitudes. Collectively, our findings support prevention of arrival and containment of spread of non-native species as a whole through effective strategies for mitigation of the rapidly amplifying impacts of invasive species. Yet, the hyper- costly taxa identified here should receive greater focus from managers to reduce impacts of current invasive species.
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  • 126
  • 127
    Publication Date: 2024-02-23
    Description: Highlights: • Ca. 418 ka Pauzhetka tephra from South Kamchatka was found in 11 marine sediment cores. • New major and trace element analyses allow identification of tephra glasses. • K/Ti and K/Fe maxima mark the Pauzhetka tephra presence in marine sediments. • The tephra occurs at Marine Isotope Stages 12 to 11c and below the Bermuda excursion. • The revised ash dispersal covers vast areas in the NW Pacific and Okhotsk Sea. Abstract: The distal Pauzhetka tephra, formed by a large caldera-forming volcanic eruption in South Kamchatka, has been identified in eleven recently recovered marine sediment cores based on major and trace element compositions of tephra glass. Ten SO264 cores form a transect along the Emperor Seamount Chain (ESC) in the Northwest (NW) Pacific between ∼50.3° and ∼45°N, 800–1200 km southeast of the Pauzhetka caldera. One additional core LV28-41-4 was retrieved in the Okhotsk Sea, ∼600 km west of the caldera. The Pauzhetka tephra glass shards have a characteristic medium-K rhyolite composition and trace element content compatible with the rear-arc position of the source volcano that ensures their identification. In the NW Pacific SO264 cores, the tephra is preserved as layers in cores 33, 47, 49, 53, 55, 56 and 62, as a lens in core 45, and as cryptotephra in cores 57 and 66. It forms a cryptotephra in the Okhotsk Sea core LV28-41-4. Distinctively high XRF-retrieved K/Ti and K/Fe ratios compared to those for the host sediments help identify the Pauzhetka tephra. According to our refined stable oxygen isotope (δ18O)- and magneto-stratigraphy of two studied and two reference cores, the Pauzhetka tephra occurs within a local δ18O maximum during a transition from marine isotope stage 12 to 11c (Termination V) and below a paleointensity minimum referred to as the Bermuda excursion, at ca. 418 ka. Using the tephra age as an isochron, we show that average linear sedimentation rates decrease southward along a transect of the SO264 cores, except in core 55. It partially reflects an intensification of mid-depth currents causing winnowing, erosion or non-deposition along the ESC over the past 418 kyr. An increased linear sedimentation rate in core 55, recovered from the southern leeward side of the Minnetonka Seamount, appears to record the pelagic accumulation protected from the mid-depth current influence. Our findings expand the former ash dispersal area farther southeast in the NW Pacific and southwest in the Okhotsk Sea. The new data on the tephra thickness supports the axis direction of the fallout zone southeast of the Pauzhetka caldera. Our results suggest the Pauzhetka tephra as a key middle Pleistocene isochron for the stratigraphy and correlation of the NW Pacific and Okhotsk Sea sediments.
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  • 128
    Publication Date: 2024-02-23
    Description: Compositional variations of amphibole stratigraphically recovered from multiple eruptions at a given volcano have a great potential to archive long-term magmatic processes in its crustal plumbing system. Calcic amphibole is a ubiquitous yet chemically and texturally diverse mineral at Mount St. Helens (MSH), where it occurs in dacites and in co-magmatic enclaves throughout the Spirit Lake stage (last ~4000 years of eruptive history). It forms three populations with distinct geochemical trends in key major and trace elements, which are subdivided into a high-Al (11–14.5 wt% Al2O3), a medium-Al (10–12.5 wt% Al2O3), and a low-Al (7.5–10 wt% Al2O3) amphibole population. The oldest investigated tephra record (Smith Creek period, 3900–3300 years BP) yields a bimodal amphibole distribution in which lower-crustal, high-Al amphibole cores (crystallized dominantly from basaltic andesite to andesite melts) and upper-crustal, low-Al amphibole rims (crystallized from rhyolitic melt) document occasional recharge of a shallow silicic mush by a more mafic melt from a lower-crustal reservoir. The sudden appearance of medium-Al amphiboles enriched in incompatible trace elements in eruptive periods younger than 2900 years BP is associated with a change in reservoir conditions toward hotter and drier magmas, which indicates recharge of the shallow silicic reservoir by basaltic melt enriched in incompatible elements. Deep-crystallizing, high-Al amphibole, however, appears mostly unaffected by such incompatible-element-enriched basaltic recharge, suggesting that these basalts bypass the lower crustal reservoir. This could be the result of the eastward offset position of the lower crustal reservoir relative to the upper crustal storage zone underneath the MSH edifice. Amphibole has proven to be a sensitive geochemical archive for uncovering storage conditions of magmas at MSH. In agreement with geophysical observations, storage and differentiation have occurred in two main zones: an upper crustal and lower crustal reservoir (the lower one being chemically less evolved). The upper crustal silicic reservoir, offset to the west of the lower crustal reservoir, has captured compositionally unusual mafic recharge (drier, hotter, and enriched in incompatible trace elements in comparison to the typical parental magmas in the region), resulting in an increased chemical diversity of amphiboles and their carrier intermediate magmas, in the last ~3000 years of MSH’s volcanic record.
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  • 129
    Publication Date: 2024-02-29
    Description: Highlights • Negligible Ba removal observed in the Rainbow hydrothermal system. • Insignificant modification of Ba isotope composition of the vent fluid endmember. • Rainbow vent introduces isotopically light Ba (−0.17) to the deep Atlantic Ocean. • Hydrothermal inputs contribute 4.6 ± 2.2 Gmol/yr Ba to the ocean. Abstract The marine barium (Ba) cycle is closely connected to the short-timescale carbon cycle, and Ba serves as a valuable paleo proxy for export production, ocean alkalinity, and terrestrial inputs. However, the marine Ba budget is poorly constrained, particularly regarding the fluxes of hydrothermally sourced Ba, which hinders our understanding of the Ba cycle and use of Ba-based proxies. Recent studies have suggested a modern source-sink imbalance of Ba isotopes in the global ocean, with sources being overall isotopically heavier than the sinks, and the hydrothermal Ba inputs were considered isotopically heavy sources. In this study, we present the first investigation of Ba and its isotopes in a non-buoyant hydrothermal plume based on dissolved and particulate samples collected from the Rainbow hydrothermal vent field on the Mid-Atlantic Ridge. Our data reveal strong hydrothermal signals at near-field stations, as evidenced by helium isotopes, accompanied by elevated concentrations of dissolved and particulate Ba. Dissolved Ba isotope compositions (δ138Ba) in hydrothermally influenced deep waters (∼0.3 ) are lighter than at similar depths of far-field stations (∼0.45 ) in the Atlantic Ocean. The concentrations and isotopic compositions of dissolved and labile particulate Ba in the non-buoyant hydrothermal plume can be explained by conservative mixing between a Ba-enriched hydrothermal component and North Atlantic Deep Water. By extrapolating the correlations to the vent fluid endmember, our results suggest that there is negligible removal of Ba, and insignificant modification of Ba isotopic signatures, from the vent fluid endmember to the non-buoyant hydrothermal plume. This indicates that the Rainbow hydrothermal system introduces isotopically light Ba (−0.17 ± 0.05 ) to the deep Atlantic Ocean. We estimate that global hydrothermal inputs of Ba are 4.6 ± 2.2 Gmol/yr. These observations highlight the potential of hydrothermal Ba to be an isotopically light source component of the marine Ba isotope budget.
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  • 130
    Publication Date: 2024-03-01
    Description: Highlights: • Transcriptomic immune response assessments in seahorse (Hippocampus erectus). • Seahorses exposed in two phases to heat-killed Vibrio and Tenacibaculum strains. • Adaptive immune memory evidence (double-exposed) and increased naivety to Tenacibaculum. • Upregulated gene expression pertaining to potential innate ‘trained immunity’. • Trained immunity potential compensator for deduced MHC II loss of function. Evolutionary adaptations in the Syngnathidae teleost family (seahorses, pipefish and seadragons) culminated in an array of spectacular morphologies, key immune gene losses, and the enigmatic male pregnancy. In seahorses, genome modifications associated with immunoglobulins, complement, and major histocompatibility complex (MHC II) pathway components raise questions concerning their immunological efficiency and the evolution of compensatory measures that may act in their place. In this investigation heat-killed bacteria (Vibrio aestuarianus and Tenacibaculum maritimum) were used in a two-phased experiment to assess the immune response dynamics of Hippocampus erectus. Gill transcriptomes from double and single-exposed individuals were analysed in order to determine the differentially expressed genes contributing to immune system responses towards immune priming. Double-exposed individuals exhibited a greater adaptive immune response when compared with single-exposed individuals, while single-exposed individuals, particularly with V. aestuarianus replicates, associated more with the innate branch of the immune system. T. maritimum double-exposed replicates exhibited the strongest immune reaction, likely due to their immunological naivety towards the bacterium, while there are also potential signs of innate trained immunity. MHC II upregulated expression was identified in selected V. aestuarianus-exposed seahorses, in the absence of other pathway constituents suggesting a possible alternative or non-classical MHC II immune function in seahorses. Gene Ontology (GO) enrichment analysis highlighted prominent angiogenesis activity following secondary exposure, which could be linked to an adaptive immune process in seahorses. This investigation highlights the prominent role of T-cell mediated adaptive immune responses in seahorses when exposed to sequential foreign bacteria exposures. If classical MHC II pathway function has been lost, innate trained immunity in syngnathids could be a potential compensatory mechanism.
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  • 131
    Publication Date: 2024-03-04
    Description: Climate change is driving compositional shifts in ecological communities directly by affecting species and indirectly through changes in species interactions. For example, competitive hierarchies can be inversed when competitive dominants are more susceptible to climate change. The brown seaweed Fucus vesiculosus is a foundation species in the Baltic Sea, experiencing novel interactions with the invasive red seaweed Gracilaria vermiculophylla, which is known for its high tolerance to environmental stress. We investigated the direct and interactive effects of warming and co-occurrence of the two algal species on their performance, by applying four climate change-relevant temperature scenarios: 1) cooling ) 2 °C below ambient – representing past conditions), 2) ambient summer temperature (18 °C), 3) IPCC RCP2.6 warming scenario (1 °C above ambient), and 4) RCP8.5 warming (3 °C above ambient) for 30 days and two compositional levels (mono and co-cultured algae) in a fully-crossed design. The RCP8.5 warming scenario increased photosynthesis, respiration, and nutrients' uptake rates of mono- and co-cultured G. vermiculophylla while growth was reduced. An increase in photosynthesis and essential nutrients' uptake and, at the same time, a growth reduction might result from increasing stress and energy demand of G. vermiculophylla under warming. In contrast, the growth of mono-cultured F. vesiculosus significantly increased in the highest warming treatment (+3 °C). The cooling treatment (−2 °C) exerted a slight negative effect only on co-cultured F. vesiculosus photosynthesis, compared to the ambient treatment. Interestingly, at ambient and warming (RCP2.6 and RCP8.5 scenarios) treatments, both F. vesiculosus and G. vermiculophylla appear to benefit from the presence of each other. Our results suggest that short exposure of F. vesiculosus to moderate or severe global warming scenarios may not directly affect or even slightly enhance its performance, while G. vermiculophylla net performance (growth) could be directly hampered by warming.
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  • 132
    Publication Date: 2024-03-05
    Description: Highlights • Mercury methylation in sediment rapidly transported into water and diatoms. • CH3Hg flux was highest for sediments with higher sulfide and organic content. • Mineral and compressed sediment released minor Hg and CH3Hg. • Higher sediment Hg species flux does not correlate with high sediment content. • Stable isotope incubations provide substantial insight to environmental Hg cycling. Abstract Mercury (Hg) is a conspicuous and persistent global pollutant. Ionic Hg can be methylated into noxious methylmercury (CH3Hg), which biomagnifies in marine tropic webs and poses a health risk to humans and organisms. Sediment Hg methylation rates are variable, and the output flux of created CH3Hg are dependent on sediment characteristics and environmental factors. Thus, uncertainties remain about the formation and flux of CH3Hg from sediment, and how this could contribute to the bioaccumulative burden for coastal organisms in shallow ecosystems. Cores were collected from 3 estuarine locations along the Eastern USA to examine how sediments characteristics influence the introduction of Hg and CH3Hg into the base of the food chain. Stable isotopes of inorganic 200Hg and CH3199Hg were injected into sediments of individual cores, with cultured diatoms constrained to overlying waters. Five different treatments were done on duplicate cores, spiked with: (1) no Hg isotopes (control); (2) inorganic 200Hg; (3) CH3199Hg; (4) both 200Hg and CH3199Hg isotopes, (5) both 200Hg and CH3199Hg into overlying waters (not sediment). Experimental cores were incubated for 3 days under temperature and light controlled conditions. These results demonstrate that upper sediments characteristics lead to high variability in Hg cycling. Notably, sediments which contained abundant and peaty organic material (∼28 %LOI), had the highest pore water DOC (3206 μM) and displayed bands of sulfur reducing bacteria yielded the greatest methylation rate (1.97 % day−1) and subsequent diatom uptake of CH3200Hg (cell quota 0.18 amol/cell) in the overlying water.
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  • 133
    Publication Date: 2024-03-05
    Description: Highlights • Solutions to the climate crisis are not ahistorical. • Both social and technical processes explain their rise (or fall) on the agenda. • Thinking about ocean CDR closely co-evolved with scientific understandings of global climate change. • Ocean CDR methods have followed cycles of hype, controversy and disappointment. • Key sociotechnical configurations and narrative changes explain the new hype around ocean CDR. Abstract While the ocean has long been portrayed as a victim of climate change, threatened by ocean warming and acidification, it is now increasingly framed as a key solution to the climate crisis. In particular, the promising carbon sequestration potential of the ocean is being emphasised. In this paper, we seek to historicise the practices, discourses and actors that have constructed the ocean as a climate change solution space. We conceptualise the debate about the mitigation potential of the ocean as a contested site of governance, where varying actors form alliances and different sociotechnical narratives about climate action play out. Using an innovative quali-quantitative methodology which combines scientometrics with document analysis, observational fieldwork, and interviews, we outline three historical phases in the history of ocean carbon sequestration that follow recurring cycles of hype, controversy and disappointment. We argue that the most recent hype around ocean carbon sequestration was not triggered by a technological breakthrough or a reduction in scientific uncertainty, but by new socio-technical configurations and coalitions. We conclude by showing that how climate change solutions are put on the agenda and become legitimised is both a scientific and political process, linked to how science frames the climate crisis, and ultimately, its governance.
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  • 134
    Publication Date: 2024-03-08
    Description: Marine heatwaves (MHWs) are widely recognized as prolonged periods of significantly elevated sea surface temperatures, leading to substantial adverse impacts on marine ecosystems. However, a comprehensive understanding of their characteristics and potential changes under climate change in the South China Sea (SCS, 0 ∼ 25°N, 105 ∼ 125°E) remains insufficient. Here, utilizing the OISST V2.0 reanalysis dataset, our study first examines MHW characteristics and their trends in the SCS during the historical period (1982 ∼ 2014). Then, in accordance with the criteria established in this study, GFDL-ESM4, EC-Earth3-Veg, NESM3, EC-Earth3, and GFDL-CM4 are identified from the CMIP6 ensemble of 19 models for their enhanced simulations of historical MHW characteristics. Moreover, considering that the fixed and sliding threshold methods offer distinct perspectives on the future evolution of MHWs, we employ both approaches to evaluate MHW characteristics under projected scenarios for the future period (2015 ∼ 2100) and subsequently compare the disparities between the two methodologies. The outcomes obtained using these methods consistently indicate that MHWs in the SCS are anticipated to intensify and persist for longer durations in the future. Besides, addressing seasonal variability, the peak intensity of MHWs falls in May during both the historical period and the four projected future scenarios. This study provides valuable insights into the behavior of MHWs in the SCS within the context of climate change, underscoring the urgency of adopting effective mitigation strategies. Especially, the use of two definition methods provides a more comprehensive set of information for understanding the future changes of MHWs in the SCS.
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  • 135
    Publication Date: 2024-03-18
    Description: Highlights: • Huidobria chilensis is an endemic shrub distributed in the south of the Atacama Desert with a disjunct population at the northern coast. • Population and genetic structure correlate with geographic distance and geological factors. • Rain fall and fog, as well as ground water, must be regarded as important factors for populations at the coast and the Andean valleys, respectively. • A combination of different software tool to analyze GBS data allowed a good understanding of the population structure and genetic diversity. Abstract: Survival in hyperarid deserts is a major challenge for life in general and for plants in particular. The Atacama Desert presents harsh conditions such as limited rainfall, crusted soils, high soil salinity, high altitude, and intense solar radiation. These conditions, together with paleoclimatic variations over the last 10 million years, have influenced the genetic structure and connectivity of plant populations, resulting in a diverse flora with high endemism. However, the diversification of most lineages appears to be relatively recent, in contrast to the reported age of the Atacama Desert and the onset and expansion of hyperarid conditions since the late Oligocene and early Miocene. A prominent exception is Huidobria chilensis (Loasaceae), which is thought to be endemic to the Atacama since the Eocene. However, it is still not understood why this plant has been successful in adapting to the harshening environmental conditions. To investigate its genetic structure in relation to the history of the Atacama Desert, we studied 186 individuals from 11 populations using genotyping-by-sequencing (GBS). A total of nearly 56 k genome-wide single nucleotide polymorphisms (SNPs) were analyzed for population structure and genetic diversity. We identified four genetic clusters corresponding to geographic regions: the coastal region south of Tocopilla, the Cordillera de la Costa around Chañaral, and the Copiapó catchment 1 and 2. Genetic diversity within and between these clusters was analyzed along with rainfall, altitude, and landscape data. Although the genetic data support `isolation by distance’ as a major factor for genetic divergence between populations, the study also reveals the influence of topography on the distribution of H. chilensis and highlights the role of hydrologically connected watersheds and rivers in plant migration and colonization. This shapes the species' evolutionary trajectory and genetic diversity. Understanding these patterns in H chilensis lets one draw general conclusions about adaptation and survival strategies of plants in extreme desert environments such as the Atacama.
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  • 136
    Publication Date: 2024-03-15
    Description: Highlights: • Microphytobenthos contributed to the particulate organic matter in both beaches. • Allochthonous materials provide relevant contributions to the POM in surf zones. • Estuarine subsidies' availability determines changes in consumers' isotopic niches. • Higher estuarine trophic subsidies resulted in narrower niches of dominant species. Abstract: Benthic invertebrates in the surf zone of exposed sandy beaches represent important links for energy circulation between benthic and pelagic food webs. This work assesses the trophic ecology of co-occurring epi- and hyper-benthic invertebrates inhabiting the surf zone of sandy beaches located close to an estuarine mouth. It illustrates that different sources of organic matter induce changes in resource utilization. The trophic positions, and the niche width and overlap of species were described using δ13C and δ15N stable isotope analysis. The contribution of different sources to the particulate organic matter was quantified through stable isotopes analysis and fatty acids profiles. Shifts in the trophic niches of dominant species reflected a decrease in the contribution of estuarine carbon to the diets along the coast. This change in contribution of estuarine carbon also influenced trophic niche properties: more diverse resources availability resulted in narrower niches without overlap while less diverse resources resulted in broad isotopic niches and a highest overlap. Results show that spatial variations in the availability of resources can modify carbon pathways and trophic interactions in coastal food webs. Whenever resources are abundant, species display a more specialized diet while food scarcity leads to broader diets, a pattern consistent with the optimal foraging theory. This resource maximization behavior commonly observed in nature is also occurring in surf zone ecosystems.
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  • 137
    Publication Date: 2024-03-22
    Description: High dissolved iron (dFe) concentrations of the order of 10-100 nmol L-1 are a feature of waters influenced by sedimentary inputs in oxygen minimum zones (OMZ). However, the temporal development of dFe concentrations is poorly defined due to a general reliance on snapshot cross-shelf sections to study marine trace metal dynamics. Multiple cruise campaigns since the 1980s have investigated Fe dynamics over the Peruvian shelf, particularly between 9-17°S where the shelf is broad, extremely productive and known to feature benthic dFe effluxes which are amongst the highest measured globally. This extensive long-term dataset uniquely allows us to study the interannual variability in dFe concentrations and their response to El Niño–Southern Oscillation (ENSO) events. By combining data from 11 cruises during the period 1984-2017 we are able to evaluate dFe dynamics on interannual timescales in a major OMZ. The region where average dFe concentrations are sensitive to variations in ENSO is confined to a subsurface layer at depths between 50-150 m, particularly in the narrow coastal region within 50 km of the coastline. Subsurface dFe concentrations were generally low during El Niño events (0.7-15.4 nmol L-1) and relatively high with a wider range of variability during the cold ENSO phase (1.1-52.1 nmol L-1). Inverse relationships between wind speed and surface/subsurface dFe were evident. In the subsurface layer, this may be attributable to enhanced dFe offshore transport along isopycnals when upwelling-favorable winds relax in accordance with previously outlined theories. Surface layer (〈40 m) dFe variability was likely associated with a dilution and/or oxidation effect depending on the strength of wind driven water column mixing. Upwelling brings macronutrient-rich water into the euphotic zone, but its intensity had a limited impact on upper layer dFe concentrations possibly due to the influence of an onshore geostrophic flow. Interannual variability in surface chlorophyll-a (Chl-a) was found to correlate with dFe concentration in the offshore zone of northern Peru. This is consistent with bioassay experiments and climatological residual nitrate concentrations which both indicate proximal Fe limitation of phytoplankton growth over and beyond the northern Peruvian shelf. Overall, our work highlights the importance of physical factors driving short-term variations in Fe availability in one of the world’s most economically important fishery regions and suggests that, despite pronounced spatial and temporal variability in dFe concentrations, the ENSO phase has an impact on dFe availability.
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  • 138
    Publication Date: 2024-03-22
    Description: Underwater image restoration has been a challenging problem for decades since the advent of underwater photography. Most solutions focus on shallow water scenarios, where the scene is uniformly illuminated by the sunlight. However, the vast majority of uncharted underwater terrain is located beyond 200 meters depth where natural light is scarce and artificial illumination is needed. In such cases, light sources co-moving with the camera, dynamically change the scene appearance, which make shallow water restoration methods inadequate. In particular for multi-light source systems (composed of dozens of LEDs nowadays), calibrating each light is time-consuming, error-prone and tedious, and we observe that only the integrated illumination within the viewing volume of the camera is critical, rather than the individual light sources. The key idea of this paper is therefore to exploit the appearance changes of objects or the seafloor, when traversing the viewing frustum of the camera. Through new constraints assuming Lambertian surfaces, corresponding image pixels constrain the light field in front of the camera, and for each voxel a signal factor and a backscatter value are stored in a volumetric grid that can be used for very efficient image restoration of camera-light platforms, which facilitates consistently texturing large 3D models and maps that would otherwise be dominated by lighting and medium artifacts. To validate the effectiveness of our approach, we conducted extensive experiments on simulated and real-world datasets. The results of these experiments demonstrate the robustness of our approach in restoring the true albedo of objects, while mitigating the influence of lighting and medium effects. Furthermore, we demonstrate our approach can be readily extended to other scenarios, including in-air imaging with artificial illumination or other similar cases.
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  • 139
    Publication Date: 2024-03-26
    Description: This review has been undertaken to understand the effectiveness of ocean acidification on oceanic micronutrient metal cycles (iron, copper and zinc) and its potential impacts on marine biota. Ocean acidification will slow down the oxidation of Fe(II) thereby retarding Fe(III) formation and subsequent hydrolysis/precipitation leading to an increase in iron bioavailability. Further, the increased primary production sustains enzymatic bacteria assisted Fe(III) reduction and subsequently the binding of weaker ligands favours the dissociation of free Fe(II) ions, thus increasing the bioavailability. The increasing pCO2 condition increases the bioavailability of copper ions by decreasing the availability of free CO32− ligand concentration. The strong complexation by dissolved organic matter may decrease the bioavailable iron and zinc ion concentration. Since ocean acidification affects the bioavailability of essential metals, studies on the uptake rates of these elements by phytoplankton should be carried out to reveal the future scenario and its effect on natural environment.
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  • 140
    Publication Date: 2024-03-25
    Description: The impact of oxygen on the preservation of organic matter in marine surface sediments is still controversial. We revisited this long-standing debate by determining the burial efficiency of sedimentary organic matter in the Black Sea, the largest anoxic and euxinic basin in the modern ocean. Surface sediments were sampled in the Danube paleodelta on the northwestern margin of the Black Sea at 420–1550 m water depth. Steady-state modeling of solid species (particulate organic carbon and nitrogen) and solutes (ammonium, sulfate, and total alkalinity) in sediments was performed to quantify rates of mass accumulation, particulate organic matter (POM) degradation, and POM burial. We develop a novel analytical model to quantify these rates applying an inverse modelling approach to down core data accounting for molecular diffusion, sediment burial and compaction. Our model results indicate that 56.7 ± 6.6 % of the particulate organic matter deposited in the study area is not degraded in surface sediments but accumulates below 10 cm sediment depth. This burial efficiency is substantially higher than those previously derived for seafloor areas underlying oxygenated bottom waters. Hence, our study confirms previous studies showing that euxinic bottom water conditions promote the preservation of particulate organic matter in marine sediments.
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  • 141
    Publication Date: 2024-03-25
    Description: The TetraEther indeX of 86 carbon atoms (TEX86) is widely used as a proxy to reconstruct past sea surface temperatures. Most current applications of TEX86 are primarily based on analyzing the composition of isoprenoid glycerol dialkyl glycerol tetraethers (isoGDGTs) that comprise TEX86 in sediments, with the assumption that the sedimentary isoGDGTs are mainly derived from the surface mixed layer. Here we report on the variations in the isoGDGT distribution, archaeal abundance and community through the water column of the Western Pacific Ocean, directly testing the export depth of isoGDGTs and constraining the temperature records of TEX86. Our data show that maximum isoGDGT concentrations occurred in subsurface waters (150–200 m) with maximum archaeal abundances. The ratio between isoGDGTs bearing 2 vs. 3 cyclopentane moieties, i.e. [2/3] ratio, increased with depth, which is likely related to the shift of the archaeal community from Ca. Nitrosopelagicus-dominance to norank_f__Nitrosopumilaceae-dominance. Models based on the [2/3] ratios in the water column predicted an average export depth of isoGDGTs to sediments of around 150–200 m, consistent with the robust relationship between the compiled sedimentary TEX86 and the annual mean subsurface temperature. Taken together, our findings support that TEX86 records subsurface rather than surface temperatures in the open ocean.
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  • 142
  • 143
    Publication Date: 2024-03-25
    Description: The ocean region along the latitude of 40oS in the South Atlantic, characterized by enhanced primary productivity, forms a transition zone between the nutrient replete but iron depleted Southern Ocean, and the nitrate and iron depleted Subtropical Gyre. Here, we present distributions of nutrient-type dissolved and particulate trace metals (dTMs and pTMs) including cadmium (Cd), nickel (Ni), copper (Cu), and zinc (Zn) in the South Atlantic from the GEOTRACES GA10 cruises. Phytoplankton uptake, riverine and atmospheric inputs shaped dTM and pTM concentrations in surface waters (dCd 27.8±36.0 pmol kg-1, n=222; dCu 0.732±0.429 nmol kg-1, n=222; dNi 3.38±0.52 nmol kg-1, n=219; dZn 0.332±0.398 nmol kg-1, n=214). Subsurface nutrients and dTMs (dCd 563±184 pmol kg-1, n=335; dCu 1.819±0.773 nmol kg-1, n=334; dNi 6.19±1.06 nmol kg-1, n=330; dZn 3.71±2.10 nmol kg-1, n=333) were controlled by the mixing of Antarctic origin waters and North Atlantic Deep Waters (NADW) with negligible contributions from local remineralization. Dissolved and particulate TMs in the Argentine Basin showed elevated concentrations towards the seafloor because of benthic inputs. Direct hydrothermal inputs of dTMs and pTMs to deep waters were not observed along the transect. The Cd-Cu-Zn-phosphate stoichiometries of Antarctic origin waters were set by a combination of dynamic physical circulation and preferential uptake of Cd, Cu, and Zn relative to phosphate in surface waters because of a dominance by diatoms in the Southern Ocean. Water mass mixing subsequently produced convoluted dCu-P and dZn-P relationships and apparent linear dCd-P and dNi-P relationships in the South Atlantic. More importantly, endmember characteristics of Antarctic waters and NADW are largely fixed in their formation regions in high latitude oceans. Therefore, the highly dynamic high latitude oceans are key regions that supply nutrients and TMs at specific ratios to low latitude oceans via the thermohaline circulation. Changes to processes in the high latitude oceans may have consequences for marine primary productivity downstream, and hence the global carbon cycle.
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  • 144
    Publication Date: 2024-03-25
    Description: Highlights • Investigation into the potential of Porites microatolls for SST reconstruction. • Comparison between recent and more conventional coral paleoclimatology methods. • Application of Srsingle bondU and Li/Mg paleothermometer. • Accuracy and reproducibility of Sr/Ca proved to be the most suitable proxy for SST reconstruction. Abstract Massive dome-shaped coral Porites are the predominant choice for paleoclimate studies due to their consistent and reliable growth. When growing close to sea level, they become limited in their vertical growth and form so-called ‘microatolls’. Microatolls have not yet been extensively explored for paleoclimate reconstruction. Here, we investigate how reliable modern Porites microatolls are against empirical sea-surface temperature using Sr/Ca, δ18O, Li/Mg and Srsingle bondU paleothermometry methods on samples from the Society Islands, French Polynesia. Our results show Sr/Ca ratios have the lowest Standard Error of the Inverse Prediction (SEIP) at 0.415 °C (N = 41) with a calibration of Sr/Ca (mmol mol−1) = −0.082 ± 0.006 SST (°C) + 11.256 ± 0.170 and with high reproducibility across multiple corals. The reproducibility of δ18O was less good, with SEIP increasing to 0.829 °C (N = 41). Considering methods directly from the literature, Li/Mg ratio empirically corrected for Sr/Ca had the best balance between bias and precision where no local calibration could be available. This study independently evaluates and confirms the suitability of Porites microatolls from well-flushed environments for paleoclimate studies. Fossil dome-shaped Porites grow anywhere between near-surface and roughly 20 m depths which inherently incorporates uncertainty into any sea surface temperature reconstruction. This uncertainty is significantly reduced for microatolls due to their well-constrained bathymetry. The study represents a fundamental step in paleoclimate research targeting consistently near the water-air interface bringing reliability and, especially when combined with their ability to reconstruct past sea-level changes, microatolls have the potential to be central for future paleoenvironmental studies.
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  • 145
    Publication Date: 2024-04-03
    Description: Highlights • Present day infiltration conditions in an monsoonal environment are studied. • Noble gas concentrations in groundwater are fixed near the soil surface. • Noble gas temperatures represent seasonal infiltration conditions in the monsoon. • Holocene and modern infiltration conditions are quite similar in southern Oman. Abstract Comparing directly measured soil temperatures with noble gas recharge temperatures (NGTs) inferred from noble gas concentrations indicates that the infiltrating soil water equilibrates with soil air near the soil surface during the rainy season. Therefore, NGTs of groundwater recently recharged by the Indian Summer Monsoon (ISM) in the Dhofar Mountains in southern Oman reflect the soil temperatures of the 3-month period and do not represent an annual mean. This finding highlights the need to account for seasonality when interpreting NGT data in regions with pronounced dry and wet seasons. We extend the observations from the southern flank of the Dhofar Mountains to three wells situated on the northern flank of the Dhofar Mountains. Two of these wells yield water of Holocene age that was recharged by the monsoon, their NGT signals are therefore classified as seasonal. The NGT calculated from a third well for recharge conditions during the Last Glacial Maximum (LGM), when the ISM was absent, is approximately 3 °C lower than that of the two Holocene wells. The lower LGM noble gas temperature corresponds well with the lower annual Sea Surface Temperature (SST) in the nearby Arabian Sea. NGTs from published studies from northern Oman are 1–3 °C higher when compared with our data of the same period in the southern Oman. We explain this regional difference of reconstructed temperatures for the LGM and Holocene groundwater with a more continental climatic influence on the infiltration conditions further to the north. The published NGTs from northern Oman show a large temperature difference between the late Holocene and the LGM. In view of our finding of seasonal NGT signals under monsoonal climate, part of this difference may reflect a change in the precipitation regime rather than in air temperature.
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  • 146
    Publication Date: 2024-04-03
    Description: Highlights • This study simulates the sedimentation-driven development of multiple stacked BSRs in the Danube paleo-delta, Black Sea. • Formation of multiple BSRs in the Black Sea is controlled by the sequence of sedimentation events of the levees induced by sea-level changes. • Kinetics of phase transitions plays a key role in the coexistence, location, and timing of the multiple BSRs. • Development of multiple stacked BSRs is possible only under a narrow range of parameters, unique for the Danube delta setting. Abstract The gas hydrate stability zone (GHSZ) is defined by pressure-temperature-salinity (pTS) constraints of natural gas hydrate (GH) system. It refers to a depth interval which usually extends several hundred meters into the sediment column at sufficient water depths. The lower boundary of the GHSZ often coincides in seismic reflection data with a bottom simulating reflector (BSR), which indicates the transition between the underlying free gas and the overlying no-free gas zone at the thermodynamic stability boundary. The GHSZ in geological systems is dynamic and can shift in response to sedimentation processes and/or changes in environmental conditions such as bottom water temperatures, hydrostatic pressure, and water salinity. The appearance of multiple BSRs has been interpreted as remnants of former GHSZ shifts which have persisted over geological timescales. In this study, we numerically simulate the sedimentation-driven development of multiple stacked BSRs in the Danube deep-sea fan in the Black Sea. We show that in this dynamic sediment depositional regime sufficient amounts of residual gas remain trapped in the former GHSZ, given sufficiently high initial gas hydrate saturations, so that paleo-BSRs could persist over long time scales (similar to 300 kyr). In particular, the formation and persistence of multiple BSRs in the Danube Delta is controlled by the sequence of sedimentation events of the levees induced by sea-level change. The kinetics of methane phase transitions between gas hydrate, dissolved methane, and free gas plays a key role in the coexistence, location and timing of the multiple BSRs. Thus, For a given permeability, distinct multiple BSRs appear only for a narrow range of GH formation (10(-14) 〈 k(f) [mol/m(2) Pa s] 〈= 10(-12)) and dissociation rates (10(-16) 〈 k(d) [mol/m(2) Pa s] 〈 10(-14)).
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  • 147
    Publication Date: 2024-04-03
    Description: Multiple stressors often act concomitantly on ecosystems but detection of species responses follows the “single species-single driver” strategy, and cumulative impacts are seldom considered. During 1990–2010, multiple perturbations in the Caspian Sea, led to the decline of kilka, sturgeon and Caspian seal populations. Specific causes for their collapse were identified but a cumulative assessment has never been carried out. Using loop analysis, a qualitative modelling technique suitable in poor-data contexts, we show how multiple drivers can be combined to assess their cumulative impact. We confirm that the decline of kilka, sturgeon and Caspian seal populations is compatible with a net effect of the concomitant perturbations. Kilkas collapse was certainly due to the outburst of M. leidyi and overfishing. In addition, the excess nutrient might have conspired to reduce these populations. The interplay between concurrent drivers produces trade-offs between opposite effects and ecosystem management must face this challenge
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  • 148
    Publication Date: 2024-04-03
    Description: Highlights • Four rhyolitic explosive eruption events were distinguished from 13.1 Ma to 11.6 Ma. • Silicic volcanism occurred at termination of subduction in a thinning lithosphere. • Rhyolites show extreme magma differentiation and reduced-dry character. • Zircon trace element and Hf isotope fingerprint is an effective correlation tool. Abstract The Tokaj Mts. volcanism occurred in a thinning continental lithosphere regime at the final stage of the subduction process. Using high-precision zircon U-Pb dating, four major explosive eruption events were distinguished. Among them the 13.1 Ma Sátoraljaújhely and the 12.0 Ma Szerencs eruptions could have yielded large amount of volcanic material (possibly 〉 100 km3) and they were associated with caldera collapse as shown by the several hundred-metre-thick pyroclastic deposits and the long (〉100 km) runout pyroclastic flow in case of the 13.1 Ma eruption. The 12.3 Ma Hegyköz and the 11.6 Ma Vizsoly eruptions were relatively smaller. The volcanic products can be readily distinguished by zircon and glass trace elements and trace element ratios, which can be used for fingerprinting and to correlate with distal deposits. The Rb, Ba, Sr content and strong negative Eu-anomaly of the glasses reflect extreme crystal fractionation, particularly for the Szerencs rhyolitic magma. The silicic volcanic products of the Tokaj Mts. show compositional similarities with the so-called ‘dry–reduced–hot’ rhyolite type consistent with an origin in an extensional environment, where the primary magmas were formed by near-adiabatic decompression melting in the mantle with subordinate fluid flux. In contrast, some of the older Bükkalja rhyolitic magmas evolved via more hydrous evolutionary paths, where amphibole played a role in the control of the trace element budget. The significant increase of zircon ε Hf values from −8.8 to + 0.2 in the rhyolitic pyroclastic rocks of Tokaj Mts. with time implies that mantle-derived magmas became more dominant. This can be explained by the specific tectonic setting, i.e. the final stage of subduction when the descending subducted slab became almost vertical, which exerted a pull in the upper lithosphere leading to thinning and accelerated subsidence as well as asthenospheric mantle flow just before the slab detachment.
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  • 149
    Publication Date: 2024-04-05
    Description: Current global warming results in rising sea-water temperatures, and the loss of sea ice in arctic and subarctic oceans impacts the community composition of primary producers with cascading effects on the food web and potentially on carbon export rates. This study analyzes metagenomic shotgun and diatom rbcL amplicon-sequencing data from sedimentary ancient DNA (sedaDNA) of the subarctic western Bering Sea that records phyto- and zooplankton community changes over the last glacial–interglacial cycle, including the last interglacial period (Eemian). Our data show that interglacial and glacial plankton communities differ, with distinct Eemian and Holocene plankton communities. The generally warm Holocene period is dominated by pico-sized cyanobacteria and bacteria-feeding heterotrophic protists, while the Eemian period is dominated by eukaryotic pico-sized chlorophytes and Triparmaceae. In contrast, the glacial period is characterized by micro-sized phototrophic protists, including sea-ice associated diatoms in the family Bacillariaceae and co-occurring diatom-feeding crustaceous zooplankton. Our deep-time record of plankton community changes reveals a long-term decrease in phytoplankton cell size coeval with increasing temperatures, and resembling community changes in the currently warming Bering Sea. The phytoplankton community in the warmer-than-present Eemian period is distinct from modern communities and limits the use of the Eemian as an analog for future climate scenarios. However, under enhanced future warming, the expected shift towards the dominance of small-sized phytoplankton and heterotrophic protists might result in an increased productivity, whereas the community’s potential of carbon export will be decreased, thereby weakening the subarctic Bering Sea’s function as an effective carbon sink.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
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  • 150
    Publication Date: 2024-04-09
    Description: The overriding physicochemical controls in seawater discussed here are the chemical composition and the state of master variables including temperature, pressure, salinity, pH and redox status. Dissolved Organic Matter also plays a major role, but since its properties are not sufficiently well quantified it is described as an emergent master variable at this stage. The theoretical basis for the treatment of equilibrium chemistry and kinetics is presented, together with projections of the future development of seawater chemistry resulting from climate change. Key points • Composition of seawater • Master variables (temperature, pressure, pH, oxygen/redox state) • The role of Dissolved Organic Matter • Equilibrium chemistry • Kinetics • The consequences of ongoing global changes
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  • 151
  • 152
    Publication Date: 2024-04-09
    Description: Highlights • Developed an innovative weighted outlier detection function that adaptively selects the best outlier detection technique, markedly improving precision and robustness in multibeam echosounder data analysis. • Demonstrated superior performance of the weighted function over traditional methods, achieving higher precision, recall, and F1 scores, pivotal for accurate seafloor mapping. • Enhanced data quality for geoscientific applications by effectively identifying and removing outliers without introducing data voids, preserving the integrity of multibeam sonar data. • The function’s significance extends to supporting sustainable environmental and resource management practices through improved accuracy in seabed mapping. • Discussed the adaptability of the method to various outlier patterns and its limitations, highlighting the need for further research and validation across different marine environments and data types. Abstract Multibeam sonar data are a valuable tool for seafloor mapping and geological studies. However, the presence of outliers in multibeam data can distort the results of analyses and reduce the accuracy of seafloor maps. In this paper, we define a weighting function based on the performance of various outlier detection techniques (OTDs) for detecting outliers in multibeam data, which calculates an outlier probability score for each sounding. Our results show that each OTD has its own strengths and weaknesses, and that a combination of outlier detection techniques is promising to improve reproducibility, explainability and the accuracy of the detection process. To address the challenge of detecting outliers in multibeam data, we propose a weighted outlier detection function that outperforms individual outlier detection techniques in terms of precision, recall and F1 scores by considering their strengths and combining them in a way that accounts for variations in the data. The function detects various types of outliers with high precision and recall values, resulting in valuable improvements in outlier detection performance for multibeam data. Overall, our proposed workflow has the potential to significantly improve the way multibeam data cleaning is performed, with the weighted outlier detection function being applied first, detecting most of the outlier automatically, followed by a domain-expert review of a small group of soundings whose automatic outlier labelling is not unequivocal.
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  • 153
    Publication Date: 2024-04-10
    Description: Trace metals (TMs) manganese (Mn), cobalt (Co), and aluminium (Al) have important geochemical and biological roles in the ocean. Here, we present full depth profiles of dissolved (d) and particulate Al, Mn, and Co along the latitude of 40 °S in the South Atlantic Ocean from the GEOTRACES GA10 cruises that operated in austral spring 2010 and summer 2011. The region is characterized by enhanced primary productivity and forms a key transition zone between the Southern Ocean and South Atlantic Subtropical Gyre. The mean concentrations of dAl, dCo, and dMn (±standard deviation) were 3.36 ± 2.65 nmol kg−1, 35.3 ± 17.6 pmol kg−1, and 0.624 ± 1.08 nmol kg−1, respectively. Their distributions in surface waters were determined by external sources and complex internal biogeochemical processes. Specifically, surface ocean dCo was controlled by the interplay between phytoplankton uptake, remineralization and external inputs; dMn was likely determined by the formation and photoreduction of Mn-oxides; and dAl was supplied by atmospheric deposition and removed by scavenging onto particles. Fluvial and sedimentary inputs near the Rio de La Plata estuary and benthic sources from the Agulhas Bank resulted in elevated dTM concentrations in near-shore surface waters. These externally sourced dTMs were effectively delivered to the open ocean by offshore diffusion and/or advection, and potentially facilitated enhanced primary productivity along the transect. The distributions of dTMs at depth were predominantly controlled by the mixing of North Atlantic Deep Water (NADW) and waters of Antarctic origin (e.g., Upper Circumpolar Water (UCDW) and Antarctic Bottom Water (AABW)). The calculated endmember concentrations of dAl and dCo in NADW showed minor decreases in the SASTG following north–south transport, suggesting removal rates of 0.064 nM/year and 0.035–0.075 pM/year, respectively. The endmember concentration of dCo in AABW was maintained at ∼30 pmol kg−1 without evidence for scavenging removal in the Southern Ocean and SASTG (time frame 〉400 years). The concentrations of dMn in NADW and AABW were between 0.1 and 0.16 nmol kg−1, and any elevated dMn concentrations were ascribed to local external inputs (e.g., from sediments in the Argentine Basin and hydrothermal activity near the Mid-Atlantic Ridge). Hence, four controlling factors (sources, internal cycling, water mass mixing and time) need to be considered when assessing TM distributions in the global ocean, even for TMs that are vulnerable to scavenging removal processes. Because the deep waters formed in high latitude oceans are crucial components of the global thermohaline overturning system, any processes (e.g., glacier melting, upwelling and sinking, and biological activity) that impact the preformed dTM concentrations in high latitude oceans will determine the downstream dTM distributions. Therefore, the sources and sinks of TMs and associated biological activity in high latitude oceans could engender basin to global scale impacts on seawater distributions of Al, Co, and Mn and their stoichiometric relationships with macronutrients, and the global biogeochemical cycles of these scavenged-type TMs.
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  • 154
    Publication Date: 2024-04-15
    Description: Fishes occur in a wider range of habitats than any other vertebrate or invertebrate group, from the upper reaches of streams in high mountain ranges to the mouths of temperate and tropical rivers, and from the intertidal zone to the ocean's abyss. Fish grow in size, spawn and die, either from natural causes (predation, diseases, ageing) or from being caught in fishing nets if the population is exploited. These dynamical processes are expressed with mathematical equations and are used in population models to estimate fisheries reference points (stock assessment), which in turn provide the basis for fisheries management. Fish populations subjected to fisheries exploitation are called fish “stocks”. Fishing has been increasingly affecting fish stocks and ecosystems both directly and indirectly, and along with the human-induced climate change they pose major threats to fish biodiversity worldwide. Using the available data stored in local or global databases to assess the status of all stocks, even the data-poor fish stocks, and following an ecosystem approach to fisheries management that incorporates effort reduction through marine protected areas, may contribute to the sustainable exploitation of fisheries resources.
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  • 155
    Publication Date: 2024-04-15
    Description: Cadmium (Cd) has a nutrient-like distribution in the ocean, similar to the macronutrient phosphate. Significant isotope fractionation induced by the biological cycling of Cd makes it a potential tracer for nutrients and productivity. However, the Cd flux and Cd isotope composition of marine sediments can also be influenced by local redox conditions and partial remineralization of organically hosted Cd. These confounding factors are under-constrained and render it challenging to use Cd as a reliable paleoproxy. To understand the relative importance of each of these processes, we examined the Cd isotope systematics of 69 modern sediments deposited across a wide range of environments. We complement these data with four profiles of particulate Cd isotope compositions from the Southern Ocean. We report three main results. First, we show that the sedimentary flux of Cd is tightly coupled to that of organic matter. Second, most Cd burial occurs in regions with some bottom-water oxygen, and the flux of CdS to anoxic regions is, globally, minor. Finally, we find that remineralization can substantially modify sedimentary Cd isotope compositions, though it is challenging to relate pelagic and sedimentary processes. For example, we find that the relationship between sedimentary Cd isotope compositions and surface seawater [Cd] is the reverse of that predicted by isotope reactor models. Likewise, sedimentary Cd isotope compositions are anti-correlated with bottom-water oxygen. While this pattern is consistent with preferential remineralization of isotopically heavy Cd, profiles of marine particulate matter reveal the reverse, whereby the Cd isotope composition of large particles, which are most likely to reach the seafloor, becomes increasingly ‘heavy’ with depth. These results highlight how productivity, redox, and remineralization all influence the flux and isotope composition of Cd to marine sediments. While our study suggests that there is no simple way to relate sedimentary Cd isotopes to surface nutrient utilization, our data point toward several potential controls that could form the basis of novel proxies for local redox conditions and remineralization.
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  • 156
    Publication Date: 2024-04-19
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  • 157
    Publication Date: 2024-04-22
    Description: Highlights: • The interactions between vortices in a four-vortex flow field using a rotating water tank. • Driven by the strain field, non-ideal vortices stretch along the centerline, and manifest an asymmetric stretching pattern. • Non-ideal vortices disperse vorticity, accumulate filaments, and exhibit distinctive variations in anti-symmetric vorticity distribution, impacting respective merging efficiency. Abstract: Oceanic vortex merging is an important physical process for the vortex evolution and its impact on marine environment. However, limitation of the in-situ oceanic observational data of vortex merging inhabits its better understanding. This study investigates the interactions between non-ideal vortices in a four-vortex flow field in a rotating tank. We examine the merging stages of anticyclonic vortices, influenced by two other cyclonic vortices and their respective dynamical behaviors and quantify the effects of merging on vortex characteristics. The results indicate a strong shear flow between two counter-rotating vortices, which accelerates the motion of the anticyclonic vortex, while cyclonic ones exhibit greater stability. Subsequently, different stages of non-ideal vortex merging in a co-rotating framework are defined, primarily the encircling stage, rapid approaching stage, and merging vortex stage. In addition, we quantify and compare variations in morphological parameters and anti-symmetric vorticity distribution of non-ideal vortices across these stages. The stretching of vortices primarily occurs along the line connecting their centers due to the strain field exerted by neighboring vortices, resulting in an asymmetric stretching pattern in the interactions among non-ideal vortices. Furthermore, during the merging process, non-ideal vortices disperse vorticity outward and accumulate vortex filaments in the surrounding environment, leading to distinctive variations in anti-symmetric vorticity distribution, affecting their respective merging efficiency.
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  • 158
    Publication Date: 2024-04-22
    Description: In the past three decades, altimeter-based remote sensing has been a widely used system to estimate ocean surface currents. However, it remains a great challenge to effectively resolve scales below ∼100 km at high latitudes and ∼ 300 km at mid-latitudes. In this study, we propose a scheme that utilizes geostrophic equilibrium and surface quasigeostrophy theory (SQG) to improve surface current resolution by incorporating remote sensing sea surface temperature (SST), sea surface height (SSH), and sea surface salinity (SSS) observations. The scheme separately characterizes the larger-scale flows and smaller-scale motions of surface currents. A case study encompassing the Agulhas surface current demonstrates that the smaller-scale motions associated with temperature fronts are well captured by introducing high spatial-temporal resolution SST data. Furthermore, the reconstructed surface current is systemically evaluated by using surface drogued drifters and a Lagrangian synthetic particle tracking tool throughout the South Indian Ocean (SIO) for 2011–2015. Notably, the reconstructed zonal velocity component is closer to the drifter observations than the meridional counterpart and corresponding velocity phase. Regionally, the Antarctic Circumpolar Current (ACC) showcases superior reconstruction performance, with higher skill scores and lower Lagrangian separation distances. However, a relatively large uncertainty is observed around the Agulhas Retroflection (AR) and Greater Agulhas System (GAS), which are linked to complicated regional dynamic regimes. We finally conduct four simulation experiments to explore the effect of different SST products on surface current reconstruction within the subdomain AR. The results indicate the varying potentials of the four evaluated SST products for informing surface current applications. Specifically, the MWIRSST enhances the likelihood of particles reaching the target field, while DMI OI shortens the average deviation distance of the arrived particles.
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  • 159
    Publication Date: 2024-04-22
    Description: Marine imaging studies have unique constraints on the data collected requiring a tool for defining the biological scope to facilitate data discovery, quality evaluation, sharing and reuse. Defining the ‘target population’ is way of scoping biological sampling or observations by setting the pool of organisms to be observed or sampled. It is used in survey design and planning, to determine statistical inference, and is critical for data interpretation and reuse (both images and derived data). We designed a set of attributes for defining and recording the target population in biological studies using marine photography, incorporating ecological and environmental delineation and marine imaging method constraints. We describe how this definition may be altered and recorded at different phases of a project. The set of attributes records the definition of the target population in a structured metadata format to enhance data FAIRness. It is designed as an extension to the image FAIR Digital Objects metadata standard, and we map terms to other biological data standards where possible. This set of attributes serves a need to update ecological metadata to align with new remotely-sensed data, and can be applied to other remotely-sensed ecological image data.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
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  • 160
    Publication Date: 2024-04-25
    Description: Highlights • Development of an autonomous DIC analyzer based on Conductometric technique using a cell with 4 hollow brass electrodes. • CO2 extraction from seawater using a gas diffusion cell with a “Tube In A Tube” configuration and a gas permeable membrane. • Formulation of mathematical temperature and salinity correction to determine accurate DIC concentration. • Demonstration of the analyzer performance in the southwest Baltic Sea. Abstract Background The increase in anthropogenic CO2 concentrations in the Earth's atmosphere since the industrial revolution has resulted in an increased uptake of CO2 by the oceans, leading to ocean acidification. Dissolved Inorganic Carbon (DIC) is one of the key variables to characterize the seawater carbonate system. High quality DIC observations at a high spatial-temporal resolution is required to improve our understanding of the marine carbonate system. To meet the requirements, autonomous DIC analyzers are needed which offer a high sampling frequency, are cost-effective and have a low reagent and power consumption. Results We present the development and validation of a novel analyzer for autonomous measurements of DIC in seawater using conductometric detection. The analyzer employs a gas diffusion sequential injection approach in a “Tube In A Tube” configuration that facilitates diffusion of gaseous CO2 from an acidified sample through a gas permeable membrane into a stream of an alkaline solution. The change in conductivity in the alkaline medium is proportional to the DIC concentration of the sample and is measured using a detection cell constructed of 4 hollow brass electrodes. Physical and chemical optimizations of the analyzer yielded a sampling frequency of 4 samples h−1 using sub mL reagent volumes for each measurement. Temperature and salinity effects on DIC measurements were mathematically corrected to increase accuracy. Analytical precision of ±4.9 μmol kg−1 and ±9.7 μmol kg−1 were achieved from measurements of a DIC reference material in the laboratory and during a field deployment in the southwest Baltic Sea, respectively. Significance This study describes a simple, cost-effective, autonomous, on-site benchtop DIC analyzer capable of measuring DIC in seawater at a high temporal resolution as a step towards an underwater DIC sensor. The analyzer is able to measure a wide range of DIC concentrations in both fresh and marine waters. The achieved accuracy and precision offer an excellent opportunity to employ the analyzer for ocean acidification studies and CO2 leakage detection in the context of Carbon Capture and Storage operations.
    Type: Article , PeerReviewed
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  • 161
    Publication Date: 2023-01-12
    Description: The surveillance of the Neapolitan volcanic area (Mt. Vesuvius, the Phlegrean Fields and the island of Ischia) represents the principal activity of the Osservatorio Vesuviano. Such an activity is carried out also through the study of ground deformations. This study deals with the use of the GPS as a powerful topographic technique. In the last two years, three GPS networks in the above mentioned area were established, with 8 vertices at Mt. Vesuvius, 20 vertices in the Island of Ischia and 30 vertices in the Phlegrean Fields. In Mt. Vesuvius area a GPS test was carried out, in order to verify the possibility of the installation of a network of GPS permanent stations. In the island of Ischia, three diferent GPS techniques (Static, Fast Static and RTK-Real Time Kinematics) have been used to get a first set of coordinates and to carry out a comparison between these in small extension areas. GPS data of the Phlegrean Fields are still in processing. The results for Mt. Vesuvius area and the island of Ischia are hereby presented and discussed.
    Description: Osservatorio Vesuviano - Napoli, Italy DISTART - Università di Bologna, Italy Università della Calabria - Cosenza, Italy Dipartimento di Costruzioni e Trasporti - Università di Padova, Italy
    Description: Published
    Description: 705-711
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: JCR Journal
    Keywords: GPS, Geodetical Networks, Static, Fast Static and RTK Survey ; 04.03. Geodesy
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 162
    Publication Date: 2023-01-13
    Description: We demonstrate a synchronous correlation technique to determine the chronology of Quaternary palaeoshorelines to test proposed relationships between tectonics, climate and sea-level change. The elevations of marine palaeoshorelines in Calabria around the active Vibo normal fault have been measured from TIN DEM 10 m data and fieldwork and correlated with global sea-level curves. A synchronous correlation method and new U/Th dates are used to ascertain how the slip-rate on the fault relates to uplift rates across the region. Regional uplift, possibly associated with subduction along the Calabrian trench or due to the cumulative effect of closely-spaced active normal faults, is rapid enough to uplift even the hangingwall of the Vibo normal fault; the actual value for the rate of background uplift can only be ascertained once the rate of slip on the Vibo fault is subtracted. Synchronous correlation of multiple palaeoshorelines sampled along 29 elevation profiles with global sea-levels shows that the resultant uplift rate (background uplift minus local hangingwall subsidence) is constant through time from 0 to 340 ka, and not fluctuating by a factor of 4 as previously suggested. The uplift rate increases from 0.4 mm/yr at the centre of the hangingwall of the fault to 1.75 mm/yr in the hangingwall in the vicinity of the fault tip. Palaeoshorelines can be traced from the hangingwall to the footwall around the fault tip and hence correlated across the fault. The throw-rate on the fault averaged over 340 ka decreases from a maximum at the centre of the fault (1 mm/yr) to zero at the tip. This gradient in throw-rate explains the spatial variation in resultant uplift rates along the fault. We interpret the 1.75 mm/yr resultant uplift rate at and beyond the fault tip as the signature of a regional uplift, presumably related to subduction, although we cannot exclude the possibility that other local faults influence this uplift; the lower uplift rates in the hangingwall of the fault are due to interaction between “regional” uplift and subsidence associated with the local active normal faulting. We discuss (a) how our synchronous correlation technique should trigger a re-appraisal of palaeoshoreline chronologies worldwide, and (b) the implications for the tectonics and seismic hazard of Calabria, suggesting that perturbations in the uplift-rate field are a key criterion to map the locations of active faults, their deformation rates, and hence seismic hazard above subduction zones.
    Description: Published
    Description: 169-187
    Description: 2T. Deformazione crostale attiva
    Description: JCR Journal
    Keywords: Active faults; Palaeoshorelines; Quaternary sea-level; Tectonics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 163
    Publication Date: 2023-01-13
    Description: The Cotentin Peninsula (Normandy, France) displays sequences of marine terraces and rasas, the latter being wide Late Cenozoic coastal erosion surfaces, that are typical of Western European coasts in Portugal, Spain, France and southern England. Remote sensing imagery and field mapping enabled reappraisal of the Cotentin coastal sequences. From bottom to top, the N Cotentin sequence includes four previously recognized Pleistocene marine terraces (T1 to T4) at elevations 〈 40 m as well as four higher and older rasas (R1 to R4) reaching 200 ± 5 m in elevation. Low-standing marine terraces are not observed in the central part of the Peninsula and a limited number of terraces are described to the south. The high-standing rasas are widespread all over the peninsula. Such strandline distributions reveal major changes during the Late Cenozoic. Progressive uplift of an irregular sea-floor led to subaerial exposure of bathymetric highs that were carved into rocky platforms, rasas and marine terraces. Eventually, five main islands coalesced and connected to the mainland to the south to form the Cotentin Peninsula. On the basis of previous dating of the last interglacial maximum terrace (i.e. Marine Isotopic Stage, MIS 5e), sequential morphostratigraphy and modelling, we have reappraised uplift rates and derived: (i) mean Upper Pleistocene (i.e. since MIS 5e ~ 122 +/− 6 ka, i.e. kilo annum) apparent uplift rates of 0.04 ± 0.01 mm/yr, (ii) mean Middle Pleistocene eustasy-corrected uplift rates of 0.09 ± 0.03 mm/yr, and (iii) low mean Pleistocene uplift rates of 0.01 mm/yr. Extrapolations of these slow rates combined with geological evidence implies that the formation of the sequences from the Cotentin Peninsula occurred between 3 Ma (Pliocene) and 15 Ma (Miocene), which cannot be narrowed down further without additional research. Along the coasts of Western Europe, sequences of marine terraces and rasas are widespread (169 preserve the MIS 5e benchmark). In Spain, Portugal, S England and other parts of western France, the sequences morphostratigraphy is very similar to that of Cotentin. The onset of such Western European sequences occurred during the Miocene (e.g. Spain) or Pliocene (e.g. Portugal). We interpret this Neogene-Quaternary coastal uplift as a symptom of the increasing lithospheric compression that accompanies Cenozoic orogenies.
    Description: Published
    Description: 338-356
    Description: 2T. Deformazione crostale attiva
    Description: JCR Journal
    Keywords: Cotentin and Western Europe; Marine terrace; Neogene and Quaternary coastal uplift; Rasa
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 164
    Publication Date: 2023-01-18
    Description: This work describes the development of an underwater anti-intrusion system based on a magnetometer self-informed network, whose purpose is to detect the presence of threats in the proximity of critical infrastructures (e.g, terrorist divers in harbours). In this context, the magnetic network fills the gaps of sonar systems at the critical boundaries of the water volume to be controlled (sea bed, docks, …), where acoustic performances deteriorate due to reflections and attenuations. The system operates in a port-protection scenario, characterized by a medium-high environmental magnetic noise that can hide the diver signal (a diver is a weak, quasi-point-like, moving source). The magnetometer network processes two inputs: the environmental magnetic noise and a signal including the target magnetic signal superimposed to the same noise; the frequencies of a diver signal lie within the noise band, hence frequency filtering proves inadequate for noise removal. The basic idea underlying the system is to measure and use the noise itself to filter the overall signal; measuring noise supports a background-subtraction process that allows to extract the target signal and therefore detect the threat presence. The effectiveness of the procedure depends on the positions of magnetometers: sensors must be close enough to one another to measure the common background noise, and, at the same time, should be distant enough from one another so that just one sensor can measure the target signal. To generate alarms when a threat is detected, a real-time software application processes data and activates a visual and acoustic alarm upon identification of a magnetic anomaly. Sea trials carried out in port areas provided extremely satisfactory results in the detection of intruders. The paper presents experimental results obtained during the method validation tests, when intruders were moving in the surrounding undersea environment.
    Description: Published
    Description: 104743
    Description: 1A. Geomagnetismo e Paleomagnetismo
    Description: 3A. Geofisica marina e osservazioni multiparametriche a fondo mare
    Description: 7SR AMBIENTE – Servizi e ricerca per la società
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 165
    Publication Date: 2023-01-18
    Description: The structure of a caldera may influence its activity, making its understanding crucial for hazard assessment. Here, we analysed high-resolution seismic profiles in the Campi Flegrei (southern Italy) offshore sector. We recognised two main fault systems, including those associated with the formation of the caldera and those affecting the resurgent dome. The former system comprises three broadly concentric fault zones (inner, medial and outer ring fault zones) depicting a nested caldera geometry. Considering the relations between faults and seismic units that represent the marine and volcaniclastic successions filling the caldera, all ring faults were formed during the Campanian Ignimbrite eruption (40 ka) and subsequently reactivated during the Neapolitan Yellow Tuff eruption (15 ka). In this last caldera-forming event, the inner and medial fault zones accommodated most of the collapse and were episodically reactivated during the younger volcano-tectonic activity. The second fault system occurs in the apical zone of the resurgent dome and comprises dominantly high-angle normal faults that are mainly related to the volcanotectonic collapse that followed the Agnano-Monte Spina Plinian eruption (4.55 ka). Finally, we provide a volcano-tectonic evolutionary model of the last 40 kyr, considering the interplay among ring and dome faults activity, volcaniclastic sedimentation, ground deformation and sea-level changes.
    Description: Published
    Description: 104723
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 166
    Publication Date: 2023-01-19
    Description: Argnani (2021, hereinafter ARG2021) commented on the paper by Barreca et al. (2021, hereinafter BRC2021) titled: “The Strait of Messina: Seismotectonics and the source of the 1908 earthquake”, in which a new seismotectonic model and constraints on the possible source fault (the so-called W-Fault) for the 1908 disastrous seismic event were provided. Results from BRC2021 led to a revision of most of the previously published papers on the issue. ARG2021 commented both on the recent activity of the W-Fault and even about its existence in the offshore. In fact, according to the author's inferences: “it may belong to a fault system that is no longer active” and, contradictorily, “the offshore occurrence of the W-Fault is not supported by the data”. The comment is mostly based on a new tectonic interpretation that the author performed directly on the BRC2021 figures, where the offshore portion of the W-fault is illustrated. In this reply, we demonstrate that the interpretation provided by ARG2021 is affected by several oversights that led the author to erroneous conclusions about the issue. Accordingly, we strongly confirm both the occurrence of the W-Fault in the offshore and the present-day activity of this structure, the only active fault capable of producing large earthquakes in the Strait of Messina area.
    Description: Published
    Description: 103962
    Description: 3T. Fisica dei terremoti e Sorgente Sismica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 167
    Publication Date: 2023-03-30
    Description: Seismic Probabilistic Tsunami Hazard Assessment (SPTHA) is a framework for calculating the probability that seismically induced tsunami waves exceed a specific threshold height, over a given time span and a specific region (i.e. regional SPTHA) or site (i.e. local SPTHA). To account for the uncertainty of the possible sources, SPTHA must integrate the results of a large number of computationally demanding tsunami simulations In this work, we innovatively use Parallel density scanned Adaptive Kriging (P-ds AK) to overcome the computational efficiency challenge of local SPTHA within a framework that consists in modeling/retrieving the full spectrum of possible earthquake triggering events at the regional level, filtering sources not relevant for the target, adopting a clustering procedure to select “representative scenarios” for inundation modeling, and, finally, adopt P-ds AK to identify the clusters centroids that most influence the hazard intensity (i.e., wave height) in the areas of interest. This approach is applied in the area of the oil refinery located in Milazzo (Italy). The application shows a consistent reduction of the number of high-resolution tsunami simulations required for the evaluation of the hazard curves over a set of inland Point of Interest (PoIs), either concentrated in one specific area or distributed along the coast.
    Description: Published
    Description: 108441
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 168
    Publication Date: 2023-03-31
    Description: The Colli Albani volcanic district emplaced huge pyroclastic-flow deposits up to 20 m thick in the southeastern suburbs of the City of Rome. The soil quality onto the gentle slopes of the Colli Albani has certainly contribute to the growth of Ancient Rome, a city with one million inhabitants as early as 2000 years ago. Interestingly, the Colli Albani soils developed on K-foiditic pyroclastic rocks with peculiar low silica, high alkali and high CaO composition. In the past, the productivity of the Colli Albani soils was maximized without the understanding of the unique physical, chemical, and mineralogical properties of these soils; now an in-depth knowledge of the Colli Albani soils is necessary to respond to the current and increasingly demand of sustainable soil use.
    Description: Published
    Description: 105430
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 169
    Publication Date: 2023-03-31
    Description: Through the analysis of seven 15 to 30 m deep boreholes drilled in the western sector of the Circus Maximus we reconstruct the aggradational history of one main tributary valley of the Tiber River in Rome, the Murcia Valley ( Vallis Murcia) .
    Description: Published
    Description: 44-53
    Description: 5A. Ricerche polari e paleoclima
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 170
    Publication Date: 2023-03-31
    Description: The Acheulian and early Middle Paleolithic assemblages from Torre in Pietra (Latium, Italy) were never securely dated before. We have now 49 Ar/39Ar dates and ESR-U-series dates which support corrrelations to marine isotope stages. The Acheulian (previously correlated to MIS 9) is now dated to MIS 10 while the Middle Paleolithic is dated to MIS 7. The analysis and comparisons of the two assemblages and comparisons with the Acheulian small tools of Castel di Guido show a culturally transmitted pattern of technology that was shared by the craftsmen of the region.
    Description: Published
    Description: 1-11
    Description: 5A. Ricerche polari e paleoclima
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 171
    Publication Date: 2023-04-04
    Description: With the aim of deepening our understanding of deep-seated fluids upwelling and mixing in large regional aquifers, we performed a hydrogeochemical study of twenty-two springs in the Contursi area (upper Sele river valley, southern Apennines) by means of the measurements of chemical-physical parameters, major ions, trace elements, and stable and radioactive isotopes. Besides, we realized two updated geo-structural cross-sections inorder to reconstruct the groundwater flowpath in the study area. The hydrogeochemical composition, as well a the water temperature allow to identify-three main groups of groundwater: Cold and Low salinity Groundwater (CLGW), Intermediate Salinity Groundwater (ISGW), and Thermal Salinity Groundwater (TSGW). The CLGW group, mostly emerging at the boundary of carbonate aquifers, is characterized by alkaline earth-bicarbonate hydrofacies. Instead, ISGW and TSGW, situated in the inner zone of the valley, show gradually a hydrogeochemical evolution towards sodium-chloride type hydrofacies domain with the highest salinity value. Stable isotope (δ18O-δD) of CLGW reveal the local meteoric origin of groundwater, while isotopic signatures of ISGW and TSGW is associated with the deep fluids inflow. CLGW hydrogeochemistry is clearly related to dissolution of carbonate rocks. On the other hand, for ISGW and TSGW an additional contribution from evaporitic rocks is supported by saturation indices values (gypsum and anhydrite) and validated by isotopic signature of dissolved sulphate (δ34S-δ18O). The application of two models based on tritium data (i.e., the piston-flow and well-mixed reservoir) attributes longer and deeper groundwater flowpaths to TSGW. Through geothermometric calculations (e,g., K-Mg and SiO2-quartz), the equilibrium temperature of deep fluids reservoir is also extrapolated (i.e., 75–96 ◦C). The results of the adopted hydrogeochemical multi-component approach allowed us to propose an interpretative model of groundwater flowpath for the Contursi area, where deep-seated tectonic discontinuities play a significant role for the upwelling of saline deep thermal fluids in shallow aquifers.
    Description: Published
    Description: 129258
    Description: 9T. Geochimica dei fluidi applicata allo studio e al monitoraggio di aree sismiche
    Description: JCR Journal
    Keywords: fluids ; earthquakes ; crust ; geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 172
    Publication Date: 2023-10-25
    Description: Boron (B) and Lithium (Li) concentrations were studied in the Platani river, one of the most important catchments of South-Central Sicily which is under semiarid climatic conditions for roughly eight months to a year. In this area, evaporites result in potential B and Li sources for surface waters. Results from river waters have measured ionic strength values between 0.1 and 4.54 M. B and Li distributions in these waters were studied in colloidal (CF, extracted by ultrafiltration from the 0.45 μm filtrate) and total dissolved (TDF) fractions and in fractions extracted from corresponding riverbed sediments, according to changes of the B/Li ratio. In river waters, CF and TDF showed very similar B/Li values, suggesting that only negligible fractionation occurs between Li and B in the aqueous phase. Similar evidence was observed between B/Li values in TDF and the labile sediment fraction, whereas an inverse relationship arose between B/Li values in TDF and in the easily reducible sediment fraction. This relationship indicates that Mn oxy-hydroxides preferentially react with aqueous B species relative to Li at the riverbed sediment interface. The extent of the B-Mn oxy-hydroxide reactions is influenced by the ionic strength, so that only B/Li values below 4 are measured in river waters with ionic strength values above 0.5 M. Comparing B/Li and ionic strength values measured in the Platani river with those from oxic brines worldwide, the same preferential B removal relative to Li is observed. This evidence suggests that B is removed as positively-charged borate ion-pairs, formed in the aqueous phase under higher ionic strength conditions, reacting with negatively charged surfaces of Mn oxy-hydroxides. The observed B reactivity relative to Li could be exploited to bring down the B excess from natural or waste waters, allowing the natural reactions with Mn oxy-hydroxides to take place under natural conditions.
    Description: Published
    Description: 135509
    Description: 1T. Struttura della Terra
    Description: JCR Journal
    Keywords: B/Li ratio; Ionic strength; Mine drainage; Mn-oxyhydroxides; Salt minerals
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 173
    Publication Date: 2023-10-24
    Description: Although explosivity is linked with high decompression rates induced by magma ascent, the quantitative relationships between decompression rate and eruption energy have yet to be properly assessed, especially for open-conduit basaltic volcanoes, where ordinary weak activity can rapidly evolve into more intense eruptions. Here, we selected three eruptions of different explosivity from Mt. Etna’s recent activity to study the relationships between the observed explosive intensities and decompression rates determined through diffusion chronometry, which is based on modeling volatile diffusion along olivine-hosted melt embayments. The approach used in this study has provided important indications on differences in the timescales of decompression-driven degassing for magmas emitted with markedly distinct eruptive dynamics, starting from similar physical and chemical conditions of the magmas involved in the three eruptions. The intense paroxysmal activity at Voragine Crater on December 3, 2015, was fostered by high decompression rate (∼0.36-0.74 MPa/s), slightly higher than in the less energetic paroxysm that occurred on February 19, 2013, at New South-East Crater (NSEC) (∼0.14-0.29 MPa/s). Decompression rates of magmas emitted during lava fountaining are one order of magnitude greater than values obtained for the mild flank eruption that occurred in December 2018 (∼0.045-0.094 MPa/s). Our results indicate that degassing kinetics controlled the intensity of activity at Mt. Etna, thus suggesting that the explosivity does not depend exclusively on the degree of overpressurization of the shallowest reservoir due to injection of gas from the deepest levels of the plumbing system.
    Description: Published
    Description: 117821
    Description: 4V. Processi pre-eruttivi
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 174
    Publication Date: 2023-10-24
    Description: •Anthropogenic CO2 flux can be estimated by stable isotopic surveying. •Gas emissions from human activities force the atmospheric CO2. •The monitoring of stable isotopes allows identifying the CO2 sources in the air. •Several tons per day of CO2 flow through the geosphere in urban zones. •Transient in the air CO2 occurs owing to changes in weather variables.
    Description: Atmospheric carbon dioxide (CO2) concentrations increase due to volcanic emissions, diffuse degassing from fault zones, and various human-caused gas emissions, especially in densely populated urban zones, which play a pivotal role in the ongoing climate change. This study aims to examine changes in the concentration and stable isotopic composition of atmospheric CO2. A laser-based analyzer provided the δ13C and δ18O values based on concentration measurements for various CO2 isotopologues. Multiple linear regression (MLR) showed that almost 30% of the atmospheric CO2 changes are caused by weather variations, while ~70% of the changes involve CO2 from various gas sources related to human activities. The Keeling plot approach was used to identify the isotopic signature of the extra CO2, which points to the gas produced by hydrocarbon combustion. An isotopic mass balance model was designed to show the relation between excess atmospheric CO2 and the flux of human-related gas emissions. Calculating the CO2 flux in the atmosphere based on this isotopic mass balance model showed that several tons of CO2 move daily between geospheres. This study shows that surveying atmospheric CO2 in urban zones allows quantifying the CO2 emissions from various sources.
    Description: Published
    Description: 119302
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: 1TR. Georisorse
    Description: 1IT. Reti di monitoraggio e sorveglianza
    Description: 2IT. Laboratori analitici e sperimentali
    Description: 6IT. Osservatori non satellitari
    Description: JCR Journal
    Keywords: CO2 flux ; Carbon stable isotopes ; Oxygen isotope composition ; Atmospheric CO2 ; Geochemical modeling ; Gas Hazard ; Stable isotopes ; Isotopes ; 01.01. Atmosphere ; 04.08. Volcanology ; environmental geochemistry
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  • 175
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    Unknown
    Elsevier
    In:  EPIC3Ecological Indicators, Elsevier, 156, pp. 111129-111129, ISSN: 1470-160X
    Publication Date: 2023-11-23
    Description: The performance of herbivore consumers in freshwater ecosystems is influenced by food quality and quantity, which are crucial factors in understanding energy flow. However, the comprehensive effects of these factors on consumer growth based on natural food research remain unclear. To address this gap, we conducted a growth experiment culturing the Cladocera Daphnia similis in natural lake water collected from 30 subtropical lakes. Our results showed that the seston concentration (SC), seston phosphorus (seston P), and seston carbon: phosphorus ratio (seston C:P, in moles) were the most important factors in influencing the growth rate of D. similis according to the Random Forest model. Specifically, the growth rate of D. similis was significantly positive correlated with SC and seston P, and significantly negative correlated with seston C:P. D. similis exhibited the optimal growth performance within the seston C:P range of 32.8 to 69.8, with a sharp decline in growth rate observed at a break point of seston C:P of 70. The combined effect of food quality and quantity on growth rate was that higher SC (≥0.26 mg C/L), lower seston C:P (≤69.80), and higher P (≥0.11 mmol/g) were associated with significantly higher growth rates. Additionally, the growth rate increased significantly with the biomass of cryptophyte, indicating the importance of food composition. Our study shows that the growth rate of D. similis is co-affected by the quality and quantity of natural food. SC, seston C:P, seston P and algae composition are reliable indicators for assessing the growth rate of consumer in freshwater ecosystems. The inhibitory effect of low C:P on consumer growth should be applied with caution when assessing the development of herbivore consumers in natural lakes.
    Repository Name: EPIC Alfred Wegener Institut
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  • 176
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    Unknown
    Elsevier
    In:  EPIC3Regional Studies in Marine Science, Elsevier, 66, pp. 103147-103147, ISSN: 2352-4855
    Publication Date: 2023-11-23
    Description: Zooplankton communities vary in space and time. Their composition is strongly influenced by lower trophic levels that are dependent on the availability of light and nutrients. As all marine ecosystems are relying on zooplankton as intermediate trophic step between primary production and higher trophic levels, changes in the zooplankton community composition and biomass can cascade through the food web with important impacts on fish communities and through that on fisheries yields. An intense fisheries exist around the Falkland Islands in the SW Atlantic Ocean, around 51° S, but to the best of our knowledge, no previous study has to date investigated the seasonal variation in zooplankton community composition in these waters. We show that copepods (39.2%), the larvae of the anomurid Grimothea gregaria (33.1%) and euphausiids (10.9%) dominate the local mesozooplankton community by biomass. All species showed seasonal patterns, including ontogenetic behaviour of G. gregaria migrating to deeper waters with development, which were significantly explained by temperature (p 〈 0.001). While overall biomass significantly decreased with distance from shore (p 〈 0.001), mesozooplankton diversity was highest at 30 km from shore. The presented study is the first assessment of the mesozooplankton biomass off the Falkland Islands and provides a first baseline to aid future ecosystem studies in the context of ecosystem based fisheries management in the region.
    Repository Name: EPIC Alfred Wegener Institut
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  • 177
    Publication Date: 2023-12-05
    Description: Water and sediment supply are essential to the health of deltaic ecosystems. Diverse datasets were integrated to better understand how climate change is shifting the supply of water and sediment to the largest polar distributary channel pattern – the Lena River Delta. Here the increase in warming rate from an average air temperature is from 4.1 °C for the period 1950–99 to 6.1 °C during 2000–21, which is higher than in the adjacent polar regions. Streamflow and sediment yield entering the Lena Delta have increased since 1988 by 56.3 km3 and 6.1×106 t, respectively; meanwhile, the Lena River’s increases in water temperature in June, July–August and September were found to be as much as 1.1, 0.6 and 0.05 °C. These changes have a pronounced effect on sediment regimes in particular parts of the delta. Based on analyses of correlations between various hydroclimatic drivers and sediment concentration changes across particular distributaries of the Lena Delta extracted from Landsat datasets, bank degradation driven by thermal erosional processes (which are in turn related to air and soil temperature increases) is proved to be the primary factor of the sediment regime in the delta. The study also highlights that sediment load changes are sensitive to wind speed due to remobilization of bottom sediment. Sums of daily air temperature and wind speed over 3 days are correlated with sediment concentration changes in the delta. The results also indicate that carbon transport across the delta (both POC and DOC) depends on sediment transport conditions and water discharge and might increase by up to 10 %. We conclude that the Lena Delta can be recognized as the global hot spot in terms of the hydrological consequences of climate change, which is altering sediment regimes, stream hydromorphology and carbon transport.
    Repository Name: EPIC Alfred Wegener Institut
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  • 178
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    Unknown
    Elsevier
    In:  EPIC3Physics Reports, Elsevier, 1031, pp. 1-59, ISSN: 0370-1573
    Publication Date: 2023-12-05
    Description: It is a fundamental challenge to understand how the function of a network is related to its structural organization. Adaptive dynamical networks represent a broad class of systems that can change their connectivity over time depending on their dynamical state. The most important feature of such systems is that their function depends on their structure and vice versa. While the properties of static networks have been extensively investigated in the past, the study of adaptive networks is much more challenging. Moreover, adaptive dynamical networks are of tremendous importance for various application fields, in particular, for the models for neuronal synaptic plasticity, adaptive networks in chemical, epidemic, biological, transport, and social systems, to name a few. In this review, we provide a detailed description of adaptive dynamical networks, show their applications in various areas of research, highlight their dynamical features and describe the arising dynamical phenomena, and give an overview of the available mathematical methods developed for understanding adaptive dynamical networks.
    Repository Name: EPIC Alfred Wegener Institut
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  • 179
    Publication Date: 2023-02-22
    Description: The understanding of the Earth’s magnetic field variations over time on the African continent is fundamental for several reasons. For instance, the most important feature of the present geomagnetic field, the South Atlantic Anomaly (SAA) characterized by weaker geomagnetic strength values than those expected for their latitudes, may have emerged in South Africa at the beginning of the second millennium CE. Here, we first selected the available volcanic and archaeomagnetic data following a set of three criteria inspired by the FAIR principles. We then built a first regional geomagnetic model for Africa covering the last 4000 years, using a revised version of the spherical cap harmonic (SCH) analysis in 2 dimensions. The new regional model shows, at the Earth’s surface, the westward migration of the SAA from the Indian Ocean over Africa since 1100 CE. In addition, the regional model is tested as a paleomagnetic dating tool by re-dating previous archaeomagnetic data from Africa and thus can be used to date other African archeological sites and the numerous active and dormant volcanoes of the East African System.
    Description: Published
    Description: 106855
    Description: 1A. Geomagnetismo e Paleomagnetismo
    Description: JCR Journal
    Keywords: geomagnetic modeling ; Africa
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 180
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    Unknown
    Elsevier
    In:  Spiess, R., Langone, A., Caggianelli, A., Stuart, F.M., Zucchi, M., Bianco, C., et al., 2021. Unveiling ductile deformation during fast exhumation of a granitic pluton in a transfer zone. J. Struct. Geol. 147, 104326.
    Publication Date: 2023-02-27
    Description: In their paper, Spiess et al. (2021) published structural, geochronological, and EBSD data on one of the monzogranite apophyses (Capo Bianco) of the buried Porto Azzurro Pluton (island of Elba, Northern Apennines, Italy), a pluton emplaced in the upper crust (P 〈 0.2 GPa; e.g. Papeschi et al., 2019). The authors published a new U/Pb age of 6.4 ± 0.4 Ma, associated with the thermal peak, and a U-Th/He apatite age of 5.0 ± 0.6 Ma, indicating cooling below 60 ◦C. Spiess et al. (2021) use these ages to model the exhumation of the pluton controlled, in their model, by the Zuccale Fault, a subhorizontal fault with 6 km of eastward displacement (ZF; Keller & Coward, 1996). Their structural dataset from the macro to the microscale and EBSD analyses relies on a small section (about 100 m wide) in the NE part of the Calamita Peninsula. Based on their documentation of (1) vertical dykes in the monzogranite, (2) vertical to low-angle top-to-the-E extensional faults, and (3) later NWstriking oblique faults, they interpret the Porto Azzurro Pluton as emplaced in an extensional to transcurrent tectonic setting, extrapolating their findings to the entire Eastern Elba.
    Description: Published
    Description: 104499
    Description: 1T. Struttura della Terra
    Description: JCR Journal
    Keywords: Upper crustal deformation ; Magmatic intrusion ; 04.04. Geology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 181
    Publication Date: 2023-02-27
    Description: Crystal zoning plays a fundamental role in modern volcanology as a key to unravel the geometry and the dynamics of plumbing systems. In this study, a detailed textural and compositional study of clinopyroxene crystals entrained in intrusive, hypabyssal and effusive products from Cima Pape (Dolomites) is coupled with thermobarometric-hygrometricmodels to reconstruct the geometry and evolution of the feeding systembeneath Middle Triassic volcanic edifices. Whole-rock major, trace element distribution and Sr-Nd isotopic signature (87Sr/86Sri = 0.7045–0.7050; 143Nd/144Ndi = 0.51223–0.51228) show that the rocks from Cima Pape are SiO2- saturated and have shoshonitic affinity, and likely belong to the acme of the Mid-Triassic magmatismthat shaped the Southern Alps between 239 and 237.6Ma. Highly porphyritic trachybasaltic to basaltic trachyandesitic volcanic rocks contain a large number of concentric-zoned clinopyroxene crystals. Here, high-Mg# and -Cr2O3, REEdepleted bands (Mg# 80–91; Cr2O3 up to 1.2 wt%) with variable thickness grew between relatively low-Mg# and -Cr2O3 (Mg# 70–77; Cr2O3 〈 0.1 wt%) augitic cores and rims. In contrast, the gabbroic to monzodioritic 50- to 300-m-thick sill cropping out belowthe volcanic sequences, though to represent a relic of the shallowest portion of the plumbing system, is mostly made up of unzoned clinopyroxene crystals. Thermobarometric and hygrometric models allowed us to define that a small “mush-type” batchwas located beneath the Cima Pape volcano at depths between 7 and 14 km. Here, augitic clinopyroxene formed in equilibrium with a slightly evolved (basaltic trachyandesitic), H2O-rich melt (Mg# = 43–45; T = 1035–1075 °C; H2O = 2.6–3.8 wt%). Periodic replenishments of the magma batch by primitive (Mg# = 65–70), hotter and relatively H2O-poor (T = 1130–1150 °C; H2O = 2.1–2.8 wt%) basaltic magmas led to the formation of diopsidic bands mantling the already formed augitic cores. Later on, re-equilibration of clinopyroxene with the mixed melt resulted in the formation of low-Mg#, LILE- and LREE-enriched rims. The most Mg-poor micro-phenocrystic clinopyroxene in the volcanic rocks and in the sill records the ultimate and shallowest conditions of crystallization, occurring at T of 975–1010 °C and P comprised between 50 and 150 MPa. Based on the presence of similar zoning in clinopyroxene phenocrysts, a comparison between the Mid-Triassic Cima Pape and active volcanoes was put forward to highlight the potential of studying ancient, entirely exposed volcanic systems for interpreting the feeding systemprocesses acting beneath active volcanoes. At a regional scale, this approach represents a new, powerful tool for investigating the evolution of the Mid-Triassic magmatism in the Southern Alps and shedding light on the interactions between mantle-derived melts and differentiated batches ponding in the crust.
    Description: Published
    Description: 107459
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 182
    Publication Date: 2023-02-25
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hudson, A. R., Peters, D. P. C., Blair, J. M., Childers, D. L., Doran, P. T., Geil, K., Gooseff, M., Gross, K. L., Haddad, N. M., Pastore, M. A., Rudgers, J. A., Sala, O., Seabloom, E. W., & Shaver, G. Cross-site comparisons of dryland ecosystem response to climate change in the US long-term ecological research network. Bioscience, 72(9), (2022): 889–907, https://doi.org/10.1093/biosci/biab134.
    Description: Long-term observations and experiments in diverse drylands reveal how ecosystems and services are responding to climate change. To develop generalities about climate change impacts at dryland sites, we compared broadscale patterns in climate and synthesized primary production responses among the eight terrestrial, nonforested sites of the United States Long-Term Ecological Research (US LTER) Network located in temperate (Southwest and Midwest) and polar (Arctic and Antarctic) regions. All sites experienced warming in recent decades, whereas drought varied regionally with multidecadal phases. Multiple years of wet or dry conditions had larger effects than single years on primary production. Droughts, floods, and wildfires altered resource availability and restructured plant communities, with greater impacts on primary production than warming alone. During severe regional droughts, air pollution from wildfire and dust events peaked. Studies at US LTER drylands over more than 40 years demonstrate reciprocal links and feedbacks among dryland ecosystems, climate-driven disturbance events, and climate change.
    Description: Funding was provided by the USDA-ARS SCINet Big Data Project (grant no. 0500–00093–001–00-D), and the National Science Foundation US LTER Program to New Mexico State University for the Jornada Basin (grant no. DEB 20–25166), Kansas State University for the Konza Prairie (grant no. DEB 2025849), the Kellogg Biological Station (grant no. DEB 1832042), Cedar Creek Ecosystem Science Reserve (grants no. DEB-1234162 and no. DEB-1831944), ARC (grant no. DEB-1637459), MCM (grant no. OPP-1637708), CAP (grant no. DEB-1832016), and SEV (grant no. DEB-1655499). Support was also provided by the Minnesota Supercomputer Institute and the University of Minnesota, Michigan State University AgBioResearch.
    Repository Name: Woods Hole Open Access Server
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  • 183
    Publication Date: 2023-02-23
    Description: Trace metals and Rare Earth Element (REE) are amply discharged by submarine hydrothermal vents, sometimes leading to the formation of ore deposits of economic interest. We report on first data on the geochemical processes involving REE and trace metals, at the solid-liquid interface, in the hydrothermal area of Levante Bay at Vulcano Island (Aeolian Archipelago, Italy). Samples were collected from several submarine springs and seeps, a mud pool and one thermal well, and analyzed for Al, Si, Ti, V, Cr, Mn, Fe, Co, As, Rb, Sr, Cs, Ba, U and REE, besides major ions. Within the bay, hydrothermal fluids contaminate seawater and promote the leaching of metals from sediments through the dissolution of CO2 and H2S, while the particulate matter removes several elements from the water. The leaching of the bottom sediments and the contribution of steam-heated water produce an enrichment of some metals and REE in the Levante Bay with respect to the concentrations expected in the ambient seawater. An enrichment up to one order of magnitude is measured for Fe, Al, Ba, Cs and Rb, and up to two orders of magnitude for Mn in the submarine samples. Other transition metals (Ti, V, Co, Cr), U, As and Sr have concentrations similar or slightly lower than the ambient seawater. REE are in concentrations higher than in ambient seawater up to two orders of magnitude. Despite being significantly higher than uncontaminated seawater, the concentrations of some metals (namely Fe, Al, Ti, Cr, V, Co, U) and REE in most samples are lower than expected by the mixing between seawater and the steam-heated water, discharging from submarine springs. Indeed, equilibrium and reaction path modeling indicate the likely precipitation of Fe-oxyhydroxides, able to remove minor elements, such as Ti, Cr, Co, V and As, and REE. The last ones are significantly removed by newly-forming solid phases, due to the presence of a large amount of Fe released by the acidic fluids through the leaching of sediments. The low pH limits the formation of solution complexes of REE with carbonate ions (the main complexing agent for REE in seawater), whereas the sorption onto particles is still effective, even at close distance from the submarine springs and seeps. This study brings new insights on the geochemical processes occurring in submarine hydrothermal systems, in particular, those in subduction-related context.
    Description: Fondo Sociale Europeo (PO FSE 2014-2020)
    Description: Published
    Description: 120756
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: JCR Journal
    Keywords: REE ; Trace metals ; Hydrothermal system ; Seawater ; 03.02. Hydrology ; 03.04. Chemical and biological ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 184
    Publication Date: 2023-02-23
    Description: Hydrogeological resources in the semiarid regions of Mexico support the economy and essential domestic activities of around 17 million people. However, adverse climatic conditions and overexploitation of aquifers affect the quantity and quality of the resource, added to problems of anthropogenic pollution and the salinity of water bodies. The Region Carbonífera aquifer represents the primary hydrogeological system in the most important coal-mining region in Mexico, located in the state of Coahuila. In this work, we present a complete dataset of 157 samples from surface and groundwaters sites have been used to characterizethe physicochemical and isotopic processes responsible for the composition of circulating waters, clarifying their origin, and to evaluate the water quality in terms of human consumption and irrigation use. The aquifer is mostly represented by Ca2+-Mg2+-SO42- and Ca2+-Mg2+-Cl- type waters, that supports salinization problems in 76% of the samples as well as sulfate excess. The origin of this chemical behavior seems to be the result of three main processes: 1) dissolution of soluble salts (gypsum, anhydrite and halite), 2) high surface evaporation under semiarid climate conditions, and 3) ionic and reverse ionic exchange. Processes 1 and 2 are also supported by the enrichment trends in the δ18O and δD signatures. For human consumption, 21% of the samples show high concentrations above the maximum permissible limits of the Official Mexican Standard (NOM-127-SSA1-1994) in total dissolved solids, Cl−, Na+, and SO42−. Additionally, 80% of the waters have some irrigation limitations due to excess sodicity or salinity. The worst quality waters for human or irrigation uses are located south of the aquifer in the municipalities of Juárez and Progreso. This study exhibits the complex hydric situation of the aquifer, raising awareness of the need to seek alternative sources, rational exploitation of resources, the use of crops that better adapt to these semiarid conditions, and intensifying hydrochemical monitoring in the region.
    Description: Published
    Description: 105307
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 185
    Publication Date: 2023-02-21
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Lozier, M., Bower, A., Furey, H., Drouin, K., Xu, X., & Zou, S. Overflow Water pathways in the North Atlantic. Progress In Oceanography, (2022): 102874, https://doi.org/10.1016/j.pocean.2022.102874.
    Description: As part of the international Overturning in the Subpolar North Atlantic Program (OSNAP), 135 acoustically-tracked deep floats were deployed to track the spreading pathways of Iceland-Scotland Overflow Water (ISOW) and Denmark Strait Overflow Water (DSOW) from 2014 to 2018. These water masses, which originate in the Nordic Seas, are transported by the deepest branch of the Atlantic Meridional Overturning Circulation (AMOC). The OSNAP floats provide the first directly-observed, comprehensive Lagrangian view of ISOW and DSOW spreading pathways throughout the subpolar North Atlantic. The collection of OSNAP float trajectories, complemented by model simulations, reveals that their pathways are (a) not restricted to western boundary currents, and (b) remarkably different from each other in character. The spread of DSOW from the Irminger Sea is primarily via the swift deep boundary currents of the Irminger and Labrador Seas, whereas the spread of ISOW out of the Iceland Basin is slower and along multiple export pathways. The characterization of these Overflow Water pathways has important implications for our understanding of the AMOC and its variability. Finally, reconstructions of AMOC variability from proxy data, involving either the strength of boundary currents and/or the property variability of deep waters, should account for the myriad pathways of DSOW and ISOW, but particularly so for the latter.
    Description: MSL gratefully acknowledges the support from the Physical Oceanography Program of the U.S. National Science Foundation (Grant OCE-2017522). ASB, HHF and SZ gratefully acknowledge the support from the Physical Oceanography Program of the U.S. National Science Foundation (Grant OCE-1756361). KLD gratefully acknowledges the support from the Physical Oceanography Program of the U.S. National Science Foundation (Grant OCE-1851075). XX gratefully acknowledges the support from the Physical Oceanography Program of the U.S. National Science Foundation (Grant OCE-2038449). RAFOS float data can be accessed at Woods Hole Open Access Server (https://doi.org/10.26025/1912/24388).
    Repository Name: Woods Hole Open Access Server
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  • 186
    Publication Date: 2023-02-24
    Description: We use the tidal deformations of the Moon induced by the Earth and the Sun as a tool for studying the inner structure of our satellite. Based on measurements of the degree-two tidal Love numbers $k_2$ and $h_2$ and dissipation coefficients from the GRAIL mission, Lunar Laser Ranging and Laser Altimetry on board of the LRO spacecraft, we perform Monte Carlo samplings for 120,000 possible combinations of thicknesses and viscosities for two classes of the lunar models. The first one includes a uniform core, a low viscosity zone (LVZ) at the core-mantle boundary, a mantle and a crust. The second one has an additional inner core. All models are consistent with the lunar t otal mass as well as its moment of inertia. By comparing predicted and observed parameters for the tidal deformations we find that the existence of an inner core cannot be ruled out. Furthermore, by deducing temperature profiles for the LVZ and an Earth-like mantle, we obtain stringent constraints on the radius (500 $\pm$ 1) km, viscosity, $(4.5 \pm 0.8) \times10^{16}$ Pa$\cdot$s and the density (3400 $\pm$ 10) kg/m$^3$ of the LVZ. We also infer the first estimation for the outer core viscosity, (2.07 ± 1.03) × 10$^{17}$ Pa·s, for tw o different possible structures: a Moon with a 70 km thick outer core and large inner core (290 km radius with a density of 6000 kg/m$^{3}$), and a Moon with a thicker outer core (169 km thick) but a denser and smaller inner core (219 km radius for 8000 kg/m$^{3}$).
    Description: Published
    Description: 115426
    Description: 5IT. Osservazioni satellitari
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 187
    Publication Date: 2023-02-21
    Description: Intra-oceanic arcs are typically associated with intermediate (andesitic) cone volcanoes. However, caldera volcanoes may also form in these settings from very large eruptions, resulting in sudden changes to the magma reservoir. These reservoirs can then produce either semi-continuous or intermittent low-intensity volcanism between major caldera-producing or caldera-deepening eruptions, providing insights into the post-caldera evolution of the system. Hunga volcano (Kingdom of Tonga, Southwest Pacific) is a large mainly submarine edifice that produced a series of caldera-forming eruptions ~900 years ago. Since then, numerous smaller-scale subaerial and submarine eruptions occurred, the most recent forming new islands in 2009 and 2014/15. Pyroclastic deposits associated with these latest eruptions have identical (range ~ 0.1 wt% of all major oxides) andesitic composition that overlap with the primitive end of the slightly wider compositional range of the caldera-forming episodes. Texturally simple plagioclase, clinopyroxene and orthopyroxene phenocrysts in pre-, syn- and post-caldera pyroclasts point to a single shallow storage reservoir at 5–8 km depth. Lack of complex zonation indicates that this reservoir is constantly resupplied by low-flux inputs of basaltic andesite magma and is large enough that convective mixing rapidly homogenises new inputs. The reservoir feeds intermittent, low-intensity, post-caldera volcanism with constant andesite composition, driven possibly by magmatic overpressure and “leakage” of gas-rich magma pockets around the edges of the caldera. More primitive and compositionally variable basaltic andesites formed a lava-dominated edifice prior to the caldera-forming event. This suggests a causal link between magma supply dynamics and caldera priming relating to the maturing of the plumbing system and formation of a sustained subvolcanic andesite magma reservoir.
    Description: This research was funded by the Faculty Research Development Fund, The University of Auckland to MB and SJC. We are grateful for financial and logistic support from ICON Films, Bristol, UK. We are especially grateful for the help and company of Lucy Meadows and Alex Holden, ICON Films, UK, during the field studies.
    Description: Published
    Description: 106614
    Description: 1V. Storia eruttiva
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: 4V. Processi pre-eruttivi
    Description: JCR Journal
    Keywords: Andesite caldera, mafic ignimbrite ; Lava Explosive volcanism ; Hunga Tonga Arc volcanism ; South Pacific volcanism ; 04.08. Volcanology
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  • 188
    Publication Date: 2023-02-21
    Description: Many vertical seismic velocity anomalies observed below different parts of the Eurasian plate are rooted in the transition zone between the upper and lower mantle (410–660 km), forming so-called secondary plumes. These anomalies are interpreted as the result of thermal effects of large-scale thermal upwelling (primary plume) in the lower mantle or deep dehydration of fluid-rich subducting oceanic plates. We present the results of thermo-mechanical numerical modelling to investigate the dynamics of such small-scale thermal and chemical (hydrous) anomalies rising from the lower part of the Earth’s upper mantle. Our objective is to determine the conditions that allow thermo-chemical secondary plumes of moderate size (initial radius of 50 km) to penetrate the continental lithosphere, as often detected in seismo-tomographic studies. To this end, we examine the effect of the following parameters: (1) the compositional deficit of the plume density due to the presence of water and hydrous silicate melts, (2) the width of the weak zone in the overlying lithosphere formed because of plume-induced magmatic weakening and/or previous tectonic events, and (3) a tectonic regime varied from neutral to extensional. In our models, secondary plumes of purely thermal origin do not penetrate the overlying plate, but flatten at its base, forming “mushroom”-shaped structures at the level of the lithosphere-asthenosphere boundary. On the contrary, plumes with enhanced density contrast due to a chemical (hydrous) component are shown to be able to pass upwards through the lithospheric mantle to shallow depths near the Moho when (1) the compositional density contrast is ≥ 100 kg m−3 and (2) the width of the lithospheric weakness zone above the plume is ≥ 100 km. An extensional tectonic regime facilitates plume penetration into the lithosphere but is not mandatory. Our findings can explain observations that have long remained enigmatic, such as the “arrow”-shaped zone of low seismic velocities below the Tengchong volcano in south-western China and the columnar (“finger”-shaped) anomaly within the lithospheric mantle discovered more than two decades ago beneath the Eifel volcanic fields in north-western Germany. It appears that a chemical component is a characteristic feature not only of conventional hydrous plumes located over presently downgoing oceanic slabs, but also of upper mantle plumes in other tectonic settings.
    Description: Published
    Description: 117819
    Description: 1T. Struttura della Terra
    Description: JCR Journal
    Keywords: plume-lithosphere interaction ; secondary plumes ; hydrous plumes ; lithosphere rheology ; mantle transition zone ; numerical modelling
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 189
    Publication Date: 2023-02-21
    Description: Continental ultramafic rock systems, through the process of serpentinization, provide chemical and biochemical pathways that lead to the production of methane. The extent to which rock-water-gas reactions and organisms supply methane in these systems is a matter of considerable discussion and debate. Deciphering the interplay of abiotic and microbial methane observed at the surface requires several lines of reasoning as well as a variety of analyses. Despite using multiple models and interpretative tools, conclusions for the origin of methane at a particular site may vary or diverge from regional or global observations. Here, we critically address how possible conclusions of microbial versus abiotic methane in continental serpentinization systems may be interpreted and reinterpreted. We review fundamental concepts, advantages and limits, for three major methane origin models: (a) abiotic CO2 hydrogenation supplying gas reservoirs, (b) derivation from fluid inclusions in olivine-rich rocks, and (c) microbialgenesis in aquifers. We use the case of methane in the Samail ophiolite of Oman as an emblematic example of multiple interpretations; we identify ambiguous information offered by methane clumped isotopes and molecular gas compositions (e.g., the meaning of gaseous hydrocarbons heavier than methane), and suggest key tools, such as radiocarbon (14C) in methane, which may solve interpretative issues. The major constraint in any model of methane origin is the capability to sustain continuous gas flows, in terms of methane emission intensity, longevity and spatial extension, such as in natural gas sedimentary systems. Overall, this review suggests that any site interpretation can benefit from a holistic approach, integrating geochemical, geological and biological data with gas flow dynamics, as well as including regional and global contextualization.
    Description: Published
    Description: 105373
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 190
    Publication Date: 2023-02-21
    Description: Sector-zoned clinopyroxene records kinetic effects imposed by variable degrees of magma undercooling, ΔT, and can be utilised to track the dynamics of magmatic systems. The partitioning of trace elements into sectors grown in different crystallographic orientations can be used as a proxy for ΔT. However, an experimental assessment of the relationship between trace element zoning and ΔT has been lacking to date. Here we present trace element data from a series of undercooling crystallisation experiments on a primitive trachybasalt from Mt. Etna (Italy), at conditions of crustal storage (400 MPa, NNO + 2), and ΔT ranging from 23 to 173 °C. Changes in ΔT were modulated by varying both resting and liquidus temperatures, the latter via the melt-H2O content of the experiments. The resting temperature was retained for 24 h to ensure the attainment of near-equilibrium conditions. High-resolution elemental mapping reveals the distribution of trace elements in individual clinopyroxene zones. Increasing ΔT drives a shift from polyhedral morphologies with Al-rich prism and Al-poor hourglass sectors (ΔT = 23–25 °C), to skeletal (ΔT = 75–123 °C) and dendritic (ΔT = 132–173 °C) crystals with Al-rich skeletons and Al-poor overgrowths. Aluminium-rich zones have higher concentrations of rare earth elements (REE) and high field strength elements (HFSE) than Al-poor zones across all investigated ΔT conditions, and overall, Al, REE and HFSE contents increase with ΔT. This indicates that tetrahedral aluminium (TAl) and associated charge-balancing mechanisms govern the incorporation of REE and HFSE within clinopyroxene. Lattice strain parameters for REE in the M2 site indicate the incorporation of light relative to heavy REE in clinopyroxene is controlled by competing effects between the strain-free partition coefficient, D0, and the optimum cation radius, r0. Critically, the middle and heavy REE switch from incompatible to compatible with increasing ΔT. Used to model fractional crystallisation, our data demonstrate that fractionation of clinopyroxene at low ΔT controls pre-eruptive melt evolution. Importantly, this indicates crystallisation of clinopyroxene in the deep portions of Mt. Etna’s plumbing system is not rapid and is unlikely to result in the early formation of dendrites. We develop a parameterisation of ΔT based on REE partitioning between experimental clinopyroxene and coexisting melt, which can be applied to sector-zoned augite crystallising from mafic alkaline magmas, to reconstruct dynamic processes and thermal pathways during magma transport and storage. Applied to sector-zoned clinopyroxene microphenocrysts and groundmass microcrysts from the 1974 eccentric eruption at Mt. Etna, our parameterisation tracks an increase in ΔT with magma ascent and eruption, following recharge of Cr-rich mafic magma at depth. Sector-zoned clinopyroxene can track ΔT variations leading to volcanism at Mt. Etna and could be applied to quantify magma dynamics in other active volcanoes.
    Description: This work was supported by a Foundation Research Excellence Award from The University of Queensland (UQ-FREA RM2019001828, T.U.), the Advance Queensland Women’s Research Assistance Program from the Queensland Government (WRAP109-2019RD1 RM2020002371, T.U.) and the HP-HT laboratory of Experimental Geophysics and Volcanology (INGV, Rome). A.M. was supported by the Australian Government Research Training Program (RTP). S.M, M.M. and A.P. were supported by the MIUR project “Time scales of solidification in magmas: Applications to Volcanic Eruptions, Silicate Melts, Glasses, Glass- Ceramics” (PRIN 2017J277S9).
    Description: Published
    Description: 249-268
    Description: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
    Description: 4V. Processi pre-eruttivi
    Description: JCR Journal
    Keywords: Clinopyroxene ; Sector Zoning ; Trace element partitioning ; Undercooling ; Dendritic crystals ; Rare earth elements ; LA ICP-MS Mapping ; Mt. Etna ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 191
    Publication Date: 2023-02-21
    Description: We compute a high-resolution topographic model of the Moho beneath the fault system activated during the 2016–2017 Central Italy seismic sequence, using Receiver Function (RF) analyses. We document that Ps conversions recorded in RF data-set varies abruptly at very short distance across the crustal lineament called Ancona-Anzio Line (AAL). Moho depth varies from about 25-30 km in the Tyrrhenian domain on the West to 35- 40 km in the Adriatic domain in the East. Where the two domains are juxtaposed along the AAL, Moho depth values cluster around 50 km depth, in a stripe-like area 20 km wide. Such unique feature marks the deformation zone in the lithosphere and testifies the abrupt change in delamination style in the two sectors of the Apennines. Intermittent large normal faulting earthquakes driven by across-belt extension break through such inherited strong structural changes, conditioned by localized barriers to fluids migration and overpressuring.
    Description: Published
    Description: 229237
    Description: 1T. Struttura della Terra
    Description: 4T. Sismicità dell'Italia
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 192
    Publication Date: 2023-03-22
    Description: Volcanic plume aerosol following the paroxysmal event of Mount Etna (Italy) in February 21st - 26th, 2021 was detected in Naples area (Italy), together with transport of Saharan dust aerosol, combining lidar, sunphotometer and satellite observations with back-trajectories and dispersion models simulations. Lidar data allowed to clearly distinguish the two main aerosol components, to investigate the spectral dependence of the aerosol optical properties and to retrieve their microphysical properties, essential for a detailed aerosol characterization. A new Monte Carlo algorithm, capable of retrieving the particle size distribution from lidar measurements, was applied. Lidar results are in good agreement with columnar integrated sunphotometer data. This combination of novel lidar observations of the vertically-resolved aerosol microphysics, column observations and modelling allows for a more complete description of multi-layered aerosol conditions.
    Description: Published
    Description: 106099
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 193
    Publication Date: 2023-03-22
    Description: Quantification of the subsurface geothermal potential primarily relies on the assessment of the thermal and mechanical configuration of the lithosphere. Such investigations require a detailed knowledge of the geological and tectonic forcing on the regional thermal, stress and hydraulic regimes and their counter feedback mechanisms. This approach becomes even more relevant in complex and active tectonic settings. In this regard, the Sicily region, which is located in the Central-Western Mediterranean, is an exceptional case study due to its almost unexplored geothermal potential hosted in a complex geodynamic setting. The present-day geological configuration resulted from the collision between the African and European plates, which led to the coexistence of compressional phases, beginning with the Oligocene-Miocene clockwise rotation of Corsica-Sardinia and alternated extensional phases in the Tyrrhenian basin due to the southward progression of the Sicilian- Maghrebian chain towards areas of the internal foreland (Hyblean domain). In this study, we attempt a reconstruction of the present-day lithospheric state of Sicily to quantify its thermal regime at shallow and intermediate depths. We have carried out a 3D lithospheric-scale gravity modelling in order to define the main geological units and their lithology-dependent rock properties, then integrated into a 3D geological model consistent with available borehole and seismic datasets. We have used the constructed geological model with its lithologydependent density, thermal conductivity, and radiogenic heat production to derive the present-day conductive thermal field as a whole and for individual tectonic or geological units, thereby considering different boundary conditions. We have finally validated results of the modelling against a shallow temperature dataset derived from hydrocarbon explorations. Our results indicate that the thermal field at depths shallower than 10 km is largely controlled by variability in sedimentary thickness in the foreland and the orogen, while deeper temperatures are primarily controlled by the distribution of the heat transferred from the mantle together with the radiogenic contribution of the shallow crystalline basement rocks and deeper crustal layers. The thermal modelling portrays a rather heterogenous Moho heat flow, locally higher than 80 mW/m2, revealing a particular geodynamic setting with specific areas characterized by high-to-medium enthalpy geothermal potential. As such, our modelling provides new perspectives for the exploration of geothermal resources in Sicily and helps to better constrain the thermal structure of the complex Sicilian collisional setting.
    Description: Published
    Description: 103976
    Description: 1TR. Georisorse
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 194
    Publication Date: 2023-03-27
    Description: The Calabrian Arc represents one of the most active sectors of the upper plate of the Tyrrhenian-Ionian subduction system. This research aims to reconstruct the evolution of the Squillace Basin (Ionian offshore of the Calabrian Arc) from the Late Miocene to Recent times and recognise active shallow and deep structures using a multiscale approach. The latter is based on interpreting high-penetration and high-resolution seismic reflection profiles, calibrated with well-log data coupled with bathymetric data and the distribution of instrumental earthquakes. Data highlight three steps in the evolution of the Squillace Basin. A Late Miocene extensional event led to the formation of WNW-ESE oriented horst and half-graben structures. During the Pliocene, deformation was localised in the central and northern sectors of the basin and expressed by a WNW-ESE oriented strike-slip fault and NW-SE normal to trastensional faults, respectively. A transpressional event started in the Early Pleistocene, causing the positive inversion of deep (〉 3 km) extensional faults and the formation of NW-SE to WNW-ESE oriented transpressional/reverse faults and related anticlines. The kinematics of these faults agree with the NW-SE oriented left-lateral Albi-Cosenza, Lamezia-Catanzaro and Petilia-Sosti crustal fault zones developed in north Calabria. The results of this work suggest that the transpressional structures in the northwestern sector of the basin likely represent the offshore prolongation of the Albi-Cosenza fault zone. NW-SE to WNW-ESE trending, shallow (〈2 km) high-angle normal faults offset the younger deposits. Their depth and direction indicate that these faults are secondary structures formed in the extrados of the anticlines associated with the transpressional faults. The distribution of earthquakes shows events with M 〉 3 and depth 〈15 km located in the hanging wall of transpressional faults. The integrated data suggest that these structures are active and probably responsible for the major earthquakes that affected the Ionian offshore.
    Description: Published
    Description: 229772
    Description: 2T. Deformazione crostale attiva
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 195
    Publication Date: 2023-03-20
    Description: Published in https://www.sciencedirect.com/science/article/pii/S0012821X22004617
    Description: Earthquake forecasting and prediction have long and in some cases sordid histories but recent work has rekindled interest based on advances in early warning, hazard assessment for induced seismicity and successful prediction of laboratory earthquakes. In the lab, frictional stick-slip events provide an analog for earthquakes and the seismic cycle. Labquakes are ideal targets for machine learning (ML) because they can be produced in long sequences under controlled conditions. Recent works show that ML can predict several aspects of labquakes using fault zone acoustic emissions. Here, we generalize these results and explore deep learning (DL) methods for labquake prediction and autoregressive (AR) forecasting. DL improves existing ML methods of labquake prediction. AR methods allow forecasting at future horizons via iterative predictions. We demonstrate that DL models based on Long-Short Term Memory (LSTM) and Convolution Neural Networks predict labquakes under several conditions, and that fault zone stress can be predicted with fidelity, confirming that acoustic energy is a fingerprint of fault zone stress. We predict also time to start of failure (TTsF) and time to the end of Failure (TTeF) for labquakes. Interestingly, TTeF is successfully predicted in all seismic cycles, while the TTsF prediction varies with the amount of preseismic fault creep. We report AR methods to forecast the evolution of fault stress using three sequence modeling frameworks: LSTM, Temporal Convolution Network and Transformer Network. AR forecasting is distinct from existing predictive models, which predict only a target variable at a specific time. The results for forecasting beyond a single seismic cycle are limited but encouraging. Our ML/DL models outperform the state-of-the-art and our autoregressive model represents a novel framework that could enhance current methods of earthquake forecasting.
    Description: Published
    Description: 117825
    Description: 3T. Fisica dei terremoti e Sorgente Sismica
    Description: JCR Journal
    Keywords: Physics - Geophysics; Physics - Geophysics; Computer Science - Computer Vision and Pattern Recognition
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 196
    Publication Date: 2023-03-20
    Description: The footwall of the surface rupturing Paganica normal fault, the source of the 2009 L’Aquila earthquake (Mw 6.1) in the Central Apennines (Italy), was investigated using integrated geological and geomorphological approaches. The aim was to constrain the active tectonics by studying the Raiale River that orthogonally crosscuts the fault trace, where it provides a useful geomorphological marker of long-term fluvial incision and footwall uplift. Using morphostratigraphy and paleomagnetic analysis, the Plio–Pleistocene morphotectonic evolution of the area was reconstructed, comprising an ancient continental basin and paleolandforms that predate the footwall incision. Starting from the Late Early Pleistocene–Middle Pleistocene, fluvial dissection was mainly due to marked river downcutting triggered by significant activity of the Paganica Fault, which caused progressive base-level lowering. The Raiale River downcutting formed five Middle–Late Pleistocene fluvial terraces, that, along with absolute Optically Stimulated Luminescence (OSL) dating, allowed the identification of paleolongitudinal profiles with a diverging downstream configuration. Terrace dating yielded a minimum incision rate of 0.25 ± 0.02 mm/a, which only partially compensates the footwall uplift and can thus be considered as a minimum value for the Paganica Fault throw rate, which could reach up to ~0.45 mm/a. In parallel, using terrestrial cosmogenic nuclides, a denudation rate of 0.02–0.04 mm/a was measured on the summit of the footwall block. This denudation is in keeping with the drainage incision, suggesting a non-steady state for the fault footwall topography and a dominance of relief growth. Last, the analysis of the modern Raiale River longitudinal profile denoted an ungraded status, with two main knickzones that we interpret as transient forms due to tectonic perturbations, likely triggered by activity of the Paganica Fault during the end Early Pleistocene and the Late Pleistocene. Considering the 2009 L’Aquila earthquake coseismic rupture, we observe that the younger transience on the Raiale River longitudinal profile, if it is of tectonic origin, could have only been produced by much larger seismic events (i.e., Mw 〉 6.5) than those documented in the area by paleoseismological investigations. The collective results confirmed that in the Central Apennines, conditions of dynamic equilibrium are often not met, and that the persistence of transient perturbations induced by tectonics should be accounted for.
    Description: The work was financially supported by the MIUR (Italian Ministry of Education, University and Research) project “FIRB Abruzzo - High-resolution analyses for assessing the seismic hazard and risk of the areas affected by the 6 April 2009 earthquake”, ref. RBAP10ZC8K_005 and RBAP10ZC8K_007, and by Agreement INGV-DPC 2012-2021. The airborne LiDAR survey performedby the Civil Protection of Friuli Venezia Giulia (Italy) was kindly released by Italian Civil Protection Department Special thanks to Simone Atzori, who provided the InSAR data.
    Description: Published
    Description: 108411
    Description: 2T. Deformazione crostale attiva
    Description: JCR Journal
    Keywords: Earthquake geology ; Active faults ; L'Aquila earthquake ; Morphotectonics ; active faulting
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 197
    Publication Date: 2023-03-20
    Description: In seismically active regions with variable dominant focal mechanisms, there is considerable tsunami inundation height uncertainty. Basic earthquake source parameters such as dip, strike, and rake affect significantly the tsunamigenic potential and the tsunami directivity. Tsunami inundation is also sensitive to other properties such as bottom friction. Despite their importance, sensitivity to these basic parameters is surprisingly sparsely studied in literature. We perform suites of systematic parameter searches to investigate the sensitivity of inundation at the towns of Catania and Siracusa on Sicily to changes both in the earthquake source parameters and the Manning friction. The inundation is modelled using the Tsunami-HySEA shallow water code on a system of nested topo-bathymetric grids with a finest spatial resolution of 10 m. This GPU-based model, with significant HPC resources, allows us to perform large numbers of high- resolution tsunami simulations. We analyze the variability of different hydrodynamic parameters due to large earthquakes with uniform slip at different locations, focal depth, and different source parameters. We consider sources both near the coastline, in which significant near-shore co-seismic deformation occurs, and offshore, where near- shore co-seismic deformation is negligible. For distant offshore earthquake sources, we see systematic and intuitive changes in the inundation with changes in strike, dip, rake, and depth. For near-shore sources, the dependency is far more complicated and co- determined by both the source mechanisms and the coastal morphology. The sensitivity studies provide directions on how to resolve the source discretization to optimize the number of sources in Probabilistic Tsunami Hazard Analysis, and they demonstrate a need for a far finer discretization of local sources than for more distant sources. For a small number of earthquake sources, we study systematically the inundation as a function of the Manning coefficient. The sensitivity of the inundation to this parameter varies greatly for different earthquake sources and topo-bathymetry at the coastline of interest. The friction greatly affects the velocities and momentum flux and to a lesser but still significant extent the inundation distance from the coastline. An understanding of all these dependencies is needed to better quantify the hazard when source complexity increases.
    Description: Published
    Description: 757618
    Description: 6T. Studi di pericolosità sismica e da maremoto
    Description: 8T. Sismologia in tempo reale e Early Warning Sismico e da Tsunami
    Description: 1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami
    Description: 3IT. Calcolo scientifico
    Description: JCR Journal
    Keywords: tsunami ; inundation ; HPC ; earthquakes ; numerical simulations
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 198
    Publication Date: 2023-03-20
    Description: The present investigation provides measurements of radon (222Rn) concentration levels in 20 thermal waters at the Campi Flegrei volcanic caldera, an important geothermal system with hydrothermal manifestations in the Neapolitan area (Southern Italy). We used a RAD7® Radon-in-air detector equipped with Big Bottle RAD H2O and DRYSTIK accessories (Durridge Co. Inc.). Water samples with different chemical and/or physical conditions, not used as drink waters, are taken from continental thermal groundwaters, springs, lakes, pools and one sub merged thermal spring. The waters are mostly chlorine to bicarbonate, except of a few sulphate types sampled at the hydrothermal discharge areas of Solfatara and Pisciarelli, central in the caldera. Water temperature and pH values range from 18.1 to 91.3 ◦C and from 2 to 8, respectively. Sampling and measurement of radon in groundwater are complicated by the high volatility of the gas; a method is here proposed. In some of the 20 sites double or triple samples were collected by using different volume polyethylene terephthalate (PET) bottles, diluting sample with blank water, and modifying flow of pumped wells. We suggest that dilution can be considered when water is i) not enough to fill in the PET, resulting in large head space in the sampler, ii) too hot determining damage of the PET or iii) too saline to clog the Big Bottle System. Dissolved radon concentrations vary from 0.1 ± 0.1 to 1146 ± 57 Bq/L with an average value of 152 Bq/L, using the CAPTURE program, the default RAD7 data acquisition program. Similar values in radon concentration are obtained using the method proposed in De Simone et al. (2015) ranging between 0.1 ± 5.8 and 1286 ± 98 Bq/L with an average value of 167 Bq/L. The hottest and most acidic sulphate waters refer to a small boiling pool at Pisciarelli hydrothermal discharge area and have nearly zero 222Rn content. 222Rn concentrations from this study are mostly below the reference level of 1000 Bq/L recommended for human health protection by the European Commission and the most adopted in the scientific community (Catao ˜et al., 2022). No correlation has been observed between temperature, pH, major anions and radon content values, nor between rock composition since it is almost homogeneous trachyte at the study sites. 222Rn levels therefore appear to reflect the local sedimentological, structural or hydrogeological conditions. The levels of 222Rn here presented are an important background for the scientific community that will intend to define the natural fluctuations of dissolved 222Rn in relation with seasons, environment, hydrogeology or volcanic dynamics at the geohazardous Campi Flegrei area.
    Description: Published
    Description: 107641
    Description: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: 6SR VULCANI – Servizi e ricerca per la società
    Description: JCR Journal
    Keywords: 222Rn ; Campi Flegrei ; RAD7 ; Big Bottle RAD H2O ; DRYSTIK ; Dissolved radon
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 199
    Publication Date: 2023-03-20
    Description: The δ18O and δ2H of rivers and springs were investigated in order to characterize the groundwater recharge sources around Nyiragongo and Nyamulagira volcanoes, in the Democratic Republic of the Congo and Rwanda. Water samples were collected monthly between November 2013 and October 2014 from 5 major rivers, 3 major cold springs, 3 tepid springs and 1 hot spring. The temperatures of each spring were nearly constant over the sampling period attesting for their groundwater character, while the temperatures of the rivers were much more variable. The rivers monthly δ2H and δ18O range from 􀀀 6.8‰ to 1.9‰ and 􀀀 3.1‰ to 1.6‰, respectively, while springs showed depleted values that span from 􀀀 10.2 to 􀀀 1.1‰ for δ2H and 􀀀 3.6 to 􀀀 1.9‰ for δ18O. Catchment morphology (formed of depression, upper footslope and medium to high gradient-mountains) and the local tectonic discontinuity (fissures and faults) regulate the surface runoff and subsurface flow, control the precipitation infiltration zones and hence the aquifers recharge areas. Chemical and isotopic (δ18O and δ2H) compositions of springs and rivers reveal the presence of shallow and deep aquifers, with some waters having intermediate isotope composition. Three different recharge zones characterized by different altitudes were identified: the first is found at low altitude ranging from ~1800 m to ~2150 m, the second and intermediate recharge zone in the altitude range from ~2180 m to ~2500 m at the upper footslope area, while the third and highest recharge area is located in the altitudes range from ~2620 to ~3220 m. The two upper recharge areas are the most fractured and fissured zones allowing rapid infiltration of depleted precipitations which recharge deep aquifers found in the tepid and hot springs. Based on their chemical and isotopic composition, waters from the shallow and deep aquifers have been considered representative of mixing end members. During their ascent to the surface, water from the deep aquifer mixes with that of shallow aquifer yielding the tepid springs of intermediate chemical and isotopic composition, while the other keep their original fingerprint corresponding to the isotopically depleted hot spring.
    Description: Published
    Description: 120778
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 200
    Publication Date: 2023-03-20
    Description: Implicit integration of the viscous term can significantly improve performance in computational fluid dynamics for highly viscous fluids such as lava. We show improvements over our previous proposal for semi-implicit viscous integration in Smoothed Particle Hydrodynamics, extending it to support a wider range of boundary models. Due to the resulting loss of matrix symmetry, a key advancement is a more robust version of the biconjugate gradient stabilized method to solve the linear systems, that is also better suited for parallelization in both shared-memory and distributed-memory systems. The advantages of the new solver are demostrated in applications with both Newtonian and non-Newtonian fluids, covering both the numerical aspect (improved convergence thanks to the possibility to use more accurate boundary model) and the computing aspect (with excellent strong scaling and satisfactory weak scaling).
    Description: Published
    Description: 111413
    Description: 3IT. Calcolo scientifico
    Description: JCR Journal
    Keywords: SPH ; Low Reynods number ; Implicit integration ; BiCGSTAB ; GPU ; 05.01. Computational geophysics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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