ALBERT

Description: In contemporary ocean science, modeling systems that integrate understanding of complex multiscale phenomena and utilize efficient numerics are paramount. Many of today's fundamental ocean science questions involve multiple scales and multiple dynamics. A new generation of modeling systems would allow to study such questions quantitatively by being less restrictive dynamically and more efficient numerically than more traditional systems.

Description: Cephalopods have been utilised in neurosci- ence research for more than 100 years particularly because of their phenotypic plasticity, complex and centralised nervous system, tractability for studies of learning and cellular mechanisms of memory (e.g. long-term potentia- tion) and anatomical features facilitating physiological studies (e.g. squid giant axon and synapse). On 1 January 2013, research using any of the about 700 extant species of ‘‘live cephalopods’’ became regulated within the European Union by Directive 2010/63/EU on the ‘‘Protection of Animals used for Scientific Purposes’’, giving cephalopods the same EU legal protection as previously afforded only to vertebrates. The Directive has a number of implications, particularly for neuroscience research. These include: (1) projects will need justification, authorisation from local competent authorities, and be subject to review including a harm-benefit assessment and adherence to the 3Rs princi- ples (Replacement, Refinement and Reduction). (2) To support project evaluation and compliance with the new EU law, guidelines specific to cephalopods will need to be developed, covering capture, transport, handling, housing, care, maintenance, health monitoring, humane anaesthesia, analgesia and euthanasia. (3) Objective criteria need to be developed to identify signs of pain, suffering, distress and lasting harm particularly in the context of their induction by an experimental procedure. Despite diversity of views existing on some of these topics, this paper reviews the above topics and describes the approaches being taken by the cephalopod research community (represented by the authorship) to produce ‘‘guidelines’’ and the potential contribution of neuroscience research to cephalopod welfare.

Description: Developmental and reproductive parameters and their relationships were studied in the marine isopod Idotea linearis. We hypothesized that (1) the temporal patterns of molting and growth undergo complex and sex-specific changes with age as well as with the onset of sexual maturation, and that (2) sexual maturation (and dependent parameters) is controlled by the photoperiod. Both males and females were singly cultured in the laboratory at two alternative photoperiods (constant long and short days, respectively) from hatching until death. Males molted and grew throughout their life, showing a steady increase in stage duration and body size with each molt. Females, in contrast, showed much more complex modifications in molt chronology due to reproductive demands. There was some variability in the stage number, when females reached maturity. Reaching maturity early in the succession of molts was associated with smaller body size at maturity, smaller size of broods, but higher average number of broods per lifetime. Post-puberty molts in females occurred without further growth, and successive broods did not differ in size. The photoperiod strongly affected sexual maturation (and thus in turn molting and growth patterns) in females, while males remained completely unaffected by the photo regime.

Description: This study examines present-day changes of the Antarctic ice sheet (AIS) by means of different data sets. We make use of monthly gravity field solutions acquired by the Gravity Recovery and Climate Experiment (GRACE) to study mass changes of the AIS for a 10-year period. In addition to "standard" solutions of release 05, solutions based on radial base functions were used. Both solutions reveal an increased mass loss in recent years. For a 6-year period surface-height changes were inferred from laser altimetry data provided by the Ice, Cloud, and land Elevation Satellite (ICESat). The basin-scale volume trends were converted into mass changes and were compared with the GRACE estimates for the same period. Focussing on the Thwaites Glacier, Landsat optical imagery was utilised to determine ice-flow velocities for a period of more than two decades. This data set was extended by means of high-resolution synthetic aperture radar (SAR) data from the TerraSAR-X mission, revealing an accelerated ice flow of all parts of the glacier. ICESat data over the Thwaites Glacier were complemented by digital elevation models inferred from TanDEM-X data. This extended data set exhibits an increased surface lowering in recent times. Passive microwave remote sensing data prove the long-term stability of the accumulation rates in a low accumulation zone in East Antarctica over several decades. Finally, we discuss the main error sources of present-day mass-balance estimates: the glacial isostatic adjustment effect for GRACE as well as the biases between laser operational periods and the volume-mass conversion for ICESat.

Description: This article aims to address the challenges of sustainable earth system governance from a multi-scale level perspective. The local to regional system level reviews findings from a social-ecological system (SES) approach of a mangrove ecosystem in North Brazil. Seven challenges (Glaser et al. 2010) that could provide relevant knowledge to society were identified. Their respective justification and recommendations are presented here. Further, these “challenges from the field” are linked and discussed with those challenges on earth system level elaborated by the International Council for Science in 2010. There it was stressed that sustainability problems are increasingly caused by drivers from multiple spatial and institutional levels in a single global human-nature system. The comparison between the global and local to regional challenges shows that most of these are reappearing disregarding the level of analysis, indicating that there is a universal core of global change problems. However, there are gaps are visible which hamper the effective connections across the different spatial levels. These gaps pertain to i.e. the subjects of knowledge generation and stakeholder inclusion. The final section elaborates on these recognized gaps and their science-policy dimensions. The article closes with the identification of a number of factors which currently impede global sustainability efforts: shortcomings in inter- and transdisciplinary research practice, lack of consistent structures for earth system governance and shortcomings in dealing with up-scaling challenges whilst remaining locally relevant. A blueprint for a globally focused but regionally informed social-ecological analysis framework remains to be worked out.

Description: Milleporidae are of high ecological and economic importance, as, together with the scleractinian corals, they belong to the main reef builders of tropical coral reefs. Coral reefs face severe threats mainly due to anthropogenic disturbance. Understanding their population structure and dynamics is crucial for any conservation effort. Here we report the first microsatellite loci for the Milleporidae. Eleven polymorphic markers were developed for the hydrozoan corals Millepora dichotoma from the Great Barrier Reef (Australia) and tested for amplification in M. dichotoma from the Red Sea (Egypt), as well as for Millepora platyphylla from the Pacific Ocean (Moorea, French Polynesia). All loci were variable with 4–15 alleles per locus. Nine loci were transferable between geographic regions and species. These are the first microsatellites for hydrozoan corals. They will provide valuable tools for characterizing the population structure and genetic diversity of the group thereby benefitting coral reef conservation.

Description: We investigated microbial life preserved in a hydrothermally inactive silica–barite chimney in comparison with an active barite chimney and sediment from the Loki’s Castle low-temperature venting area at the Arctic Mid-Ocean Ridge (AMOR) using lipid biomarkers. Carbon and sulfur isotopes were used to constrain possible metabolic pathways. Multiple sulfur (δ34S, ∆33S) isotopes on barite over a cross section of the extinct chimney range between 21.1 and 22.5 ‰ in δ34S, and between 0.020 and 0.034 ‰ in Δ33S, indicating direct precipitation from seawater. Biomarker distributions within two discrete zones of this silica–barite chimney indicate a considerable difference in abundance and diversity of microorganisms from the chimney exterior to the interior. Lipids in the active and inactive chimney barite and sediment were dominated by a range of 13C-depleted unsaturated and branched fatty acids with δ13C values between −39.7 and −26.7 ‰, indicating the presence of sulfur-oxidizing and sulfate-reducing bacteria. The majority of lipids (99.5 %) in the extinct chimney interior that experienced high temperatures were of archaeal origin. Unusual glycerol monoalkyl glycerol tetraethers (GMGT) with 0–4 rings were the dominant compounds suggesting the presence of mainly (hyper-) thermophilic archaea. Isoprenoid hydrocarbons with δ13C values as low as −46 ‰ also indicated the presence of methanogens and possibly methanotrophs.

Description: Der Klimawandel, die Globalisierung der Märkte, der demografische Wandel, die rasanten technologischen Entwicklungen sowie die Veränderungen der Landnutzung sind verschiedene Facetten des sogenannten Globalen Wandels. Welchen Einfluss der Globale Wandel auf die verfügbaren Wasserressourcen hat, ist von Region zu Region unterschiedlich. In jedem Fall steigt der Nutzungsdruck auf die Georessource Wasser weiter an; bereits jetzt zeichnen sich regionale Konkurrenzen und Konflikte bei der Nutzung ab. So wird sich beispielsweise der Bewässerungsbedarf der Landwirtschaft durch die steigende globale Nachfrage nach Nahrungsmitteln und Rohstoffen weiter erhöhen. Infolge des Globalen Wandels und der Veränderungen der Flusslandschaften ist auch vermehrt mit Hochwasserereignissen zu rechnen. Ausreichende Wasserressourcen in hinreichender Qualität zu sichern, sowie der Gewässerschutz und die Hochwasservorsorge sind daher zentrale Anliegen unserer Gesellschaft. Innovative Anpassungsstrategien und neue Technologien können hierbei nicht nur zu einer nachhaltigen Wasser- und Bodenbewirtschaftung führen, sondern gleichzeitig auch wirtschaftliche Chancen auf dem Weltmarkt eröffnen. Gerade durch die Entwicklung und den Export von Technologien und Verfahrensweisen kann Deutschland einen Beitrag zur Lösung globaler Wasserprobleme leisten.

Description: Understanding phylogenetic relationship and patterns of contemporary population genetic structure is a prerequisite for conservation and management of potential fishery resources. In this study we report the isolation and characterization of 11 polymorphic microsatellite loci for the squat lobster Munida gregaria from around the Falkland Islands/Islas Malvinas. The number of alleles ranged from 3 to 31, observed heterozygosity varied from 0.130 to 0.870. Cross-amplification was 100 % successfully in the species/morph M. subrugosa and 36.4 % in another congeneric species M. gracilis. This set of microsatellites is useful for studies focused on taxonomy, genetic diversity and genetic connectivity further may provide stock assessment information for monitoring this important fishery resource.

Description: Marine habitats worldwide are increasingly pressurized by climate change, especially along the Antarctic Peninsula. Well-studied areas in front of rapidly retreating tidewater glaciers like Potter Cove are representative for similar coastal environments and, therefore, shed light on habitat formation and development on not only a local but also regional scale. The objective of this study was to provide insights into habitat distribution in Potter Cove, King George Island, Antarctica, and to evaluate the associated environmental processes. Furthermore, an assessment concerning the future development of the habitats is provided. To describe the seafloor habitats in Potter Cove, an acoustic seabed discrimination system (RoxAnn) was used in combination with underwater video images and sediment samples. Due to the absence of wave and current measurements in the study area, bed shear stress estimates served to delineate zones prone to sediment erosion. On the basis of the investigations, two habitat classes were identified in Potter Cove, namely soft-sediment and stone habitats that, besides influences from sediment supply and coastal morphology, are controlled by sediment erosion. A future expansion of the stone habitat is predicted if recent environmental change trends continue. Possible implications for the Potter Cove environment, and other coastal ecosystems under similar pressure, include changes in biomass and species composition.

Description: ICE BINDING PROTEINS FROM SEA ICE ALGAE Sea ice is mainly a two-phase system, and its porous structure is largely determinant for biological activity within ice. During ice formation, solutes in the seawater are excluded from the ice matrix and segregate into brine droplets or brine channels, generally defined as brine inclusions inside sea ice. Outflow of high salinity brine and inflow of seawater of lower salinity, as well as further cooling, cause brine inclusions to narrow and eventually separate into individual pockets divided by ice bridges. Despite the harsh conditions that govern within sea ice, where temperatures range from about -1.8°C on the bottom to -20°C or less on the top, and brine salinities can be as high as 200 on the Practical Salinity Scale, brine inclusions offer a habitat for a variety of microalgae. These algae play a crucial role for the ecology of the Polar Oceans, since they represent a concentrated food source in the low-productivity ice-covered sea, and in the months of melting they initiate blooms by seeding the water column. Algae have been found distributed within brine inclusions throughout the entire thickness of the ice column. The strategies adopted by ice microorganisms to cope with conditions in sea ice remain to be unraveled. Recent studies showed that several organisms that populate sea ice, spreading from bacteria to diatoms and a crustacean species, have ice binding proteins (IBPs). These proteins are common in polar species, but lack in temperate organisms, suggesting that IBPs play a key role in adaptation to subzero conditions. The nomenclature of these proteins varies, depending on authors, from ice binding to antifreeze or ice structuring. In the generally accepted adsorption–inhibition model describing the mechanism of action of IBPs, proteins bind to the ice lattice and locally inhibit ice growth by the Gibbs-Thomson effect. Recent publications showed that some IBPs organize water molecules into an ice-like structure that matches defined planes of the ice crystal and is then gradually frozen to the ice lattice. One of the most prominent and best described effects of IBPs is thermal hysteresis, which describes the lowering of the freezing point of a solution below the melting point. Another effect which defines IBPs is inhibition of recrystallization, which is the grain boundary migration resulting in a growth of larger crystals at the expenses of small grains. The biological role of IBPs from sea ice microalgae remains an open question. The importance of some IBP families, as observed in fishes or insects, lies in lowering the freezing point below environmental temperature, in order to avoid ice formation in cells or organs. Other IBPs have the function to inhibit recrystallization, as it has been suggested for plant IBPs. In the context of sea ice, it seems unlikely that the biological role of IBPs may be thermal hysteresis (measured in the order of 1°C) or recrystallization inhibition. Most of the IBPs from sea ice algae are active extracellularly. It has been suggested that they are trapped and accumulate within a layer of extracellular polysaccharide substances (EPS) secreted by several sea ice organisms. Microalgal IBPs produced recombinantly or collected from spent growth medium affect the structure of ice surface, causing pitting and characteristic microstructural features. This suggests that the proteins shape their frozen environment in order to increase their habitable space within sea ice. However, the characterization of IBPs is of relevance not only to understand their functional role in sea ice, but also in the frame of possible applications of IBPs in the medical field, in the food industry and in other fields related to a control of ice crystals. In the following we present some standard techniques to determine the protein activity in terms of thermal hysteresis (TH) and recrystallization inhibition (RI), which define the proteins as ice binding. Also, we present further methods (ice pitting assay, determination of the nucleating temperature) to characterize the activity of IBPs.

Description: Characteristics of cyclones (frequency, intensity and size) and their changes in the Arctic region in a warmer climate have been analyzed with the use of the HIRHAM regional climate model simulations with SRES-A1B anthropogenic scenario for the twenty first century. The focus was on cyclones for the warm (April–September) and cold (October–March) seasons. The present-day cyclonic characteristics from HIRHAM simulations are in general agreement with those from ERA–40 reanalysis data. Differences noted for the frequency of cyclones are related with different spatial resolution in the model simulations and reanalysis data. Potential future changes in cyclone characteristics at the end of the twenty first century have been analyzed. According to the model simulations, the frequency of cyclones is increasing in warm seasons and decreasing in cold seasons for a warmer climate in the twenty first century, but these changes are statistically insignificant. Noticeable changes were detected for the intensity and size of cyclones for the both seasons. Significant increase was found for the frequency of weak cyclones during cold season. Further, a general increase in the frequency of small cyclones was calculated in cold seasons, while its frequency decreases in warm seasons.

Description: Predation of eggs and nauplii by adult copepods is often used to explain unexpected death rates in population dynamics studies, but the phenomenon has been rarely investigated or quantified. Therefore, we studied the predatory feeding of adult females (Acartia clausi, Centropages hamatus, Centropages typicus, and Temora longicornis) on their own and other species’ eggs and young nauplii with different densities of single animal-prey, mixtures of animal-prey and in the presence of diatoms. All species preyed on eggs and nauplii of their own and all other species. Maximal egg predation varied between 7 and 64 eggs fem−1 day−1. Ingestion of Centropages spp. eggs was lowest, potentially due to the spiny egg surface. Maximal feeding rates on nauplii ranged from 5 to 45 nauplii fem−1 day−1. T. longicornis preferred eggs, when eggs and nauplii were offered together at the same densities, and the other predators selected for nauplii. At a diatom concentration of 60 μg C l−1 predation on eggs by C. typicus was higher than without algae, whereas A. clausi and T. longicornis did not change their uptake of eggs. Feeding on nauplii in the presence of diatoms was again enhanced in C. typicus, and unaffected in A. clausi and C. hamatus. T. longicornis reduced its feeding on nauplii in the presence of diatoms. Calculated predation rates, using field abundances of predators and prey, suggest that predation of copepods on their own young stages may account for ca. 30 % of total mortality of young stages in North Sea copepod populations.

Description: Young larval stages of many organisms represent bottlenecks in the life-history of many species. The high mortality commonly observed in, for example, decapod larvae has often been linked to poor nutrition, with most studies focussing on food quantity. Here, we focus instead on the effects of quality and have investigated its effects on the nutritional condition of lobster larvae. We established a tri-trophic food chain consisting of the cryptophyte Rhodomonas salina, the calanoid copepod Acartia tonsa and larvae of the European lobster Homarus gammarus. In a set of experiments, we manipulated the C:N:P stoichiometry of the primary producers, and accordingly those of the primary consumer. In a first experiment, R. salina was grown under N- and P-limitation and the nutrient content of the algae was manipulated by addition of the limiting nutrient to create a food quality gradient. In a second experiment, the effect on lobster larvae of long- and short-term exposure to food of varying quality during ontogenetic development was investigated. The condition of the lobster larvae was negatively affected even by subtle N- and P-nutrient limitations of the algae. Furthermore, younger lobster larvae were more vulnerable to nutrient limitation than older ones, suggesting an ontogenetic shift in the capacity of lobster larvae to cope with low quality food. The results presented here might have substantial consequences for the survival of lobster larvae in the field, as, in the light of future climate change and re-oligotrophication of the North Sea, lobster larvae might face marked changes in temperature and nutrient conditions, thus significantly altering their condition and growth.

Description: The digestive ability of four sympatric land crabs species (the gecarcinids, Gecarcoidea natalis and Discoplax celeste and the anomurans, Birgus latro and Coenobita perlatus) was examined by determining the activity of their digestive enzymes. The gecarcinids are detritivores that consume mainly leaf litter; the robber crab, B. latro, is an omnivore that preferentially consumes items high in lipid, carbohydrate and/or protein; C. perlatus is also an omnivore/detritivore. All species possess protease, lipase and amylase activity for hydrolysing ubiquitous protein, lipid and storage polysaccharides (glycogen and starch). Similarly all species possess enzymes such as N-acetyl-β-d-glucosaminidase, the cellulases, endo-β-1,4-glucanase and β-glucohydrolase and hemicellulases, lichenase and laminarinase for the respective hydrolysis of structural substrates chitin, cellulose and hemicelluloses, lichenan and laminarin. Except for the enzyme activities of C. perlatus, enzyme activity could not be correlated to dietary preference. Perhaps others factors such as olfactory and locomotor ability and metabolic status may determine the observed dietary preferences. The digestive fluid of C. perlatus possessed higher endo-β-1,4-glucanase, lichenase and laminarinase activities compared to that of the other species. Thus, C. perlatus may be efficient at digestion of cellulose and hemicellulose within plant material. Zymography indicated that the majority of protease, lipase, phosphatase, amylase, endo-β-1,4-glucanase, β-glucohydrolase and N-acetyl-β-d-glucosaminidase isozymes were common to all species, and hence were inherited from a common aquatic ancestor. Differences were observed for the phosphatase, lipase and endo-β-1,4-glucanase isozymes. These differences are discussed in relation to phylogeny and possible evolution to cope with the adoption of a terrestrial diet.

Description: Understanding the biogeochemical processes reg- ulating carbon cycling is central to mitigating atmospheric CO2 emissions. The role of living organisms has been accounted for, but the focus has traditionally been on contributions of plants and microbes. We develop the case that fully ‘‘animating’’ the carbon cycle requires broader consideration of the functional role of animals in mediating biogeochemical processes and quanti- fication of their effects on carbon storage and exchange among terrestrial and aquatic reservoirs and the atmosphere. To encourage more hypothesis-driven experimental research that quantifies animal effects we discuss the mecha- nisms by which animals may affect carbon ex- changes and storage within and among ecosystems and the atmosphere. We illustrate how those mechanisms lead to multiplier effects whose magnitudes may rival those of more tra- ditional carbon storage and exchange rate esti- mates currently used in the carbon budget. Many animal species are already directly managed. Thus improved quantitative understanding of their influence on carbon budgets may create oppor- tunity for management and policy to identify and implement new options for mitigating CO2 re- lease at regional scales.

Description: Seasonal dynamics in the activity of Arctic shelf benthos have been the subject of few local studies, and the pronounced among-site variability characterizing their results makes it difficult to upscale and generalize their conclusions. In a regional study encompassing five sites at 100–595 m water depth in the southeastern Beau- fort Sea, we found that total pigment concentrations in surficial sediments, used as proxies of general food supply to the benthos, rose significantly after the transition from ice-covered conditions in spring (March–June 2008) to open-water conditions in summer (June–August 2008), whereas sediment Chl a concentrations, typical markers of fresh food input, did not. Macrobenthic biomass (including agglutinated foraminifera [500 lm) varied significantly among sites (1.2–6.4 g C m-2 in spring, 1.1–12.6 g C m-2 in summer), whereas a general spring-to-summer increase was not detected. Benthic carbon remineralisation also ranged significantly among sites (11.9–33.2 mg C m-2 day-1 in spring, 11.6–44.4 mg C m-2 day-1 in summer) and did in addition exhibit a general significant increase from spring-to-summer. Multiple regression analysis suggests that in both spring and summer, sediment Chl a concentration is the prime determinant of benthic carbon remineralisation, but other factors have a significant secondary influence, such as foraminiferan biomass (negative in both seasons), water depth (in spring) and infaunal biomass (in summer). Our findings indicate the importance of the combined and dynamic effects of food supply and benthic community patterns on the carbon remineralisation of the polar shelf benthos in seasonally ice-covered seas.

Description: Why a chapter on Perspectives and Integration in SOLAS Science in this book? SOLAS science by its nature deals with interactions that occur: across a wide spectrum of time and space scales, involve gases and particles, between the ocean and the atmosphere, across many disciplines including chemistry, biology, optics, physics, mathematics, computing, socio-economics and consequently interactions between many different scientists and across scientific generations. This chapter provides a guide through the remarkable diversity of cross-cutting approaches and tools in the gigantic puzzle of the SOLAS realm. Here we overview the existing prime components of atmospheric and oceanic observing systems, with the acquisition of ocean–atmosphere observables either from in situ or from satellites, the rich hierarchy of models to test our knowledge of Earth System functioning, and the tremendous efforts accomplished over the last decade within the COST Action 735 and SOLAS Integration project frameworks to understand, as best we can, the current physical and biogeochemical state of the atmosphere and ocean commons. A few SOLAS integrative studies illustrate the full meaning of interactions, paving the way for even tighter connections between thematic fields. Ultimately, SOLAS research will also develop with an enhanced consideration of societal demand while preserving fundamental research coherency. The exchange of energy, gases and particles across the air-sea interface is controlled by a variety of biological, chemical and physical processes that operate across broad spatial and temporal scales. These processes influence the composition, biogeochemical and chemical properties of both the oceanic and atmospheric boundary layers and ultimately shape the Earth system response to climate and environmental change, as detailed in the previous four chapters. In this cross-cutting chapter we present some of the SOLAS achievements over the last decade in terms of integration, upscaling observational information from process-oriented studies and expeditionary research with key tools such as remote sensing and modelling. Here we do not pretend to encompass the entire legacy of SOLAS efforts but rather offer a selective view of some of the major integrative SOLAS studies that combined available pieces of the immense jigsaw puzzle. These include, for instance, COST efforts to build up global climatologies of SOLAS relevant parameters such as dimethyl sulphide, interconnection between volcanic ash and ecosystem response in the eastern subarctic North Pacific, optimal strategy to derive basin-scale CO2 uptake with good precision, or significant reduction of the uncertainties in sea-salt aerosol source functions. Predicting the future trajectory of Earth’s climate and habitability is the main task ahead. Some possible routes for the SOLAS scientific community to reach this overarching goal conclude the chapter.

Description: In this experimental study, we compared the embryonic respiration rate in air and water of six East African sesarmid species with intertidal, supratidal and arboreal habits, to highlight possible adaptations in embryonic metabolism to their different lifestyles. The embryos of all analysed crabs showed bimodal respiration, but we did not find a trend towards an enhanced embryonic oxygen uptake in air from the intertidal to the arboreal and supratidal species. However, the late-stage embryos of the most land-adapted species, Chiromantes spp., showed an enhanced metabolism when immersed in sea water that we interpreted as an adaptive recovery mechanism to cope with the storage of by-products due to marine-based metabolic pathways during long emersion periods. Thus, we showed that the embryos of land-adapted species, although still strongly water dependent, are well adapted to semi-terrestrial habitats and represent a minor limiting factor for females, which are not restricted in their emersion period by the oxygen requirements of their embryos.

Description: Mussels Mytilus galloprovincialis have been used as model bivalves to study the impacts of global warming on their physiological performance in Themaikos Gulf, North Greece. The studies have been conducted under laboratory and field conditions for more than 6 years and focused on the biochemical, metabolic, physiological and energetic responses of M. galloprovincialis to increases in the ambient temperature. Here we summarize the findings concerning the responses of mussels to environmental temperature, present an integrated model of their physiological performance during thermal stress and discuss these findings in the light of the predicted temperature changes in the Thermaikos Gulf from the regional climate trends and the mean global temperature projections for the period 1990–2100 based on IS92 emission scenarios of the Intergovernmental Panel for Climate Change (IPCC). Our findings indicate that mussels in Themaikos Gulf currently face the temperatures close to their upper thermal limits, especially during the summer, and thus are likely vulnerably to any further increase in the temperature such as expected during the global warming

Description: Symbiotic dinoflagellates of the genus Symbiodinium, also called zooxanthellae, are found in association with a wide diversity of shallow-water anthozoans. The Symbiodinium genus includes numerous lineages, also referred to as clades or phylotypes, as well as a wide diversity of genetic sub-clades and sub-phylotypes. There are few studies characterizing the genetic diversity of zooxanthellae in Mediterranean anthozoans. In this study, we included anthozoans from the Western Mediterranean Sea and by means of internal transcriber (ITS) and large sub-unit (LSU) rRNA markers we corroborate what has been previously identified, demonstrating that phylotype “Temperate A” is very common among host Cnidaria in this basin. Our finding of fixed differences in ITS and LSU markers that correspond to different host taxa, indicate that this clade may comprise several closely-related species. Previous studies have reported the occurrence of Symbiodinium psygmophilum (formerly subclade B2) associated with Oculina patagonica and Cladocora caespitosa in the Eastern Mediterranean. Here, we identify this association in O. patagonica from the Western Mediterranean but not in C. caespitosa, suggesting some differences in symbiotic combinations between the Western and Eastern Mediterranean Basins.

Description: The endemic Antarctic brown macroalga Desmarestia anceps colonizes the subtidal between 5 and 30 m in Potter Cove on King George Island (South Shetland Islands, Antarctica). Experiments were conducted to study photosynthetic activities, antioxidative enzymes and UV tolerance of field-grown individuals with respect to the light histories along different subtidal positions. Individuals collected from the upper (5.5 m) and mid-subtidal (9.0 m) are characterized by high maximum electron transport rates (ETRmax) measured by PAM-fluorometry and high activities of superoxide dismutase (SOD) supported by considerable activities of glutathione reductase. Individuals of this species from the upper subtidal are able to tolerate high irradiances of UV-B radiation because its photosynthetic apparatus is putatively well protected by phlorotannins. In contrast, individuals from lower subtidal positions (13.5 and 15.5 m) showed an opposite trend: lower ETRmax and SOD activities as well as a lower UV tolerance of photosynthesis. Moreover, a non-denaturing polyacrylamide gel electrophoresis (native PAGE) of a partially purified crude extract reveals that D. anceps has probably six isoforms of SOD. These intra-specific patterns imply a high phenotypical plasticity of D. anceps with respect to its photosynthesis and photoprotective mechanisms. Overall, photosynthesis, UV tolerance and antioxidative potential are highly regulated in D. anceps corresponding to the respective light regimes along its natural growth sites.

Description: © The Authors, 2009. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Estuaries and Coasts 33 (2010): 15-29, doi:10.1007/s12237-009-9244-y.

Description: Future estuarine geomorphic change, in response to climate change, sea-level rise, and watershed sediment supply, may govern ecological function, navigation, and water quality. We estimated geomorphic changes in Suisun Bay, CA, under four scenarios using a tidal-timescale hydrodynamic/sediment transport model. Computational expense and data needs were reduced using the morphological hydrograph concept and the morphological acceleration factor. The four scenarios included (1) present-day conditions; (2) sea-level rise and freshwater flow changes of 2030; (3) sea-level rise and decreased watershed sediment supply of 2030; and (4) sea-level rise, freshwater flow changes, and decreased watershed sediment supply of 2030. Sea-level rise increased water levels thereby reducing wave-induced bottom shear stress and sediment redistribution during the wind-wave season. Decreased watershed sediment supply reduced net deposition within the estuary, while minor changes in freshwater flow timing and magnitude induced the smallest overall effect. In all future scenarios, net deposition in the entire estuary and in the shallowest areas did not keep pace with sea-level rise, suggesting that intertidal and wetland areas may struggle to maintain elevation. Tidal-timescale simulations using future conditions were also used to infer changes in optical depth: though sea-level rise acts to decrease mean light irradiance, decreased suspended-sediment concentrations increase irradiance, yielding small changes in optical depth. The modeling results also assisted with the development of a dimensionless estuarine geomorphic number representing the ratio of potential sediment import forces to sediment export forces; we found the number to be linearly related to relative geomorphic change in Suisun Bay. The methods implemented here are widely applicable to evaluating future scenarios of estuarine change over decadal timescales.

Description: This study was supported by the US Geological Survey’s Priority Ecosystems Science program, CALFED Bay/ Delta Program, and the University of California Center for Water Resources.

Description: This paper is not subject to U.S. copyright. The definitive version was published in Geo-Marine Letters 31 (2011): 237-248, doi:10.1007/s00367-011-0228-0.

Description: Mechanisms and timescales responsible for pockmark formation and maintenance remain uncertain, especially in areas lacking extensive thermogenic fluid deposits (e.g., previously glaciated estuaries). This study characterizes seafloor activity in the Belfast Bay, Maine nearshore pockmark field using (1) three swath bathymetry datasets collected between 1999 and 2008, complemented by analyses of shallow box-core samples for radionuclide activity and undrained shear strength, and (2) historical bathymetric data (report and smooth sheets from 1872, 1947, 1948). In addition, because repeat swath bathymetry surveys are an emerging data source, we present a selected literature review of recent studies using such datasets for seafloor change analysis. This study is the first to apply the method to a pockmark field, and characterizes macro-scale (〉5 m) evolution of tens of square kilometers of highly irregular seafloor. Presence/absence analysis yielded no change in pockmark frequency or distribution over a 9-year period (1999–2008). In that time pockmarks did not detectably enlarge, truncate, elongate, or combine. Historical data indicate that pockmark chains already existed in the 19th century. Despite the lack of macroscopic changes in the field, near-bed undrained shear-strength values of less than 7 kPa and scattered downcore 137Cs signatures indicate a highly disturbed setting. Integrating these findings with independent geophysical and geochemical observations made in the pockmark field, it can be concluded that (1) large-scale sediment resuspension and dispersion related to pockmark formation and failure do not occur frequently within this field, and (2) pockmarks can persevere in a dynamic estuarine setting that exhibits minimal modern fluid venting. Although pockmarks are conventionally thought to be long-lived features maintained by a combination of fluid venting and minimal sediment accumulation, this suggests that other mechanisms may be equally active in maintaining such irregular seafloor morphology. One such mechanism could be upwelling within pockmarks induced by near-bed currents.

Description: Graduate support for Brothers came from a Maine Economic Improvement Fund Dissertation Fellowship.

Description: © The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chinese Science Bulletin 56 (2011): 2828-2838, doi:10.1007/s11434-011-4619-4.

Description: During January–May in 2007, the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR). This was also the first active hydrothermal field found along an ultraslow-spreading ridge. We analyzed mineralogical, textural and geochemical compositions of the sulfide chimneys obtained from the 49°39′E field. Chimney samples show a concentric mineral zone around the fluid channel. The mineral assemblages of the interiors consist mainly of chalcopyrite, with pyrite and sphalerite as minor constitunets. In the intermediate portion, pyrite becomes the dominant mineral, with chalcopyrite and sphalerite as minor constitunets. For the outer wall, the majority of minerals are pyrite and sphalerite, with few chalcopyrite. Towards the outer margin of the chimney wall, the mineral grains become small and irregular in shape gradually, while minerals within interstices are abundant. These features are similar to those chimney edifices found on the East Pacific Rise and Mid-Atlantic Ridge. The average contents of Cu, Fe and Zn in our chimney samples were 2.83 wt%, 45.6 wt% and 3.28 wt%, respectively. The average Au and Ag contents were up to 2.0 ppm and 70.2 ppm respectively, higher than the massive sulfides from most hydrothermal fields along mid-ocean ridge. The rare earth elements geochemistry of the sulfide chimneys show a pattern distinctive from the sulfides recovered from typical hydrothermal fields along sediment-starved mid-ocean ridge, with the enrichment of light rare earth elements but the weak, mostly negative, Eu anomaly. This is attributed to the distinct mineralization environment or fluid compositions in this area.

Description: This work was supported by the China Ocean Mineral Resources Research and Development Association Program (DY115- 02-1-01) and the State Oceanic Administration Youth Science Fund (2010318).

Description: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Plant and Soil 356 (2012): 405-417, doi:10.1007/s11104-012-1130-x.

Description: Soil warming from global climate change could increase decomposition of fine woody debris (FWD), but debris size and quality may mitigate this effect. The goal of this study was to investigate the effect of soil warming on decomposition of fine woody debris of differing size and quality. We placed FWD of two size classes (2 × 20 cm and 4 × 40 cm) and four species (Acer saccharum, Betula lenta, Quercus rubra and Tsuga canadensis) in a soil warming and ambient area at Harvard Forest in central Massachusetts. We collected the debris from each area over two years and measured mass loss and lignin concentration. Warming increased mass loss for all species and size classes (by as much as 30%), but larger debris and debris with higher initial lignin content decomposed slower than smaller debris and debris with lower initial lignin content. Lignin degradation did not follow the same trends as mass loss. Lignin loss from the most lignin-rich species, T. canadensis, was the highest despite the fact that it lost mass the slowest. Our results suggest that soil warming will increase decomposition of FWD in temperate forests. It is imperative that future models and policy efforts account for this potential shift in the carbon storage pool.

Description: © The Author(s), 2010. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Natural Hazards 63 (2012): 51-84, doi:10.1007/s11069-010-9622-6.

Description: Waters from the Atlantic Ocean washed southward across parts of Anegada, east-northeast of Puerto Rico, during a singular event a few centuries ago. The overwash, after crossing a fringing coral reef and 1.5 km of shallow subtidal flats, cut dozens of breaches through sandy beach ridges, deposited a sheet of sand and shell capped with lime mud, and created inland fields of cobbles and boulders. Most of the breaches extend tens to hundreds of meters perpendicular to a 2-km stretch of Anegada’s windward shore. Remnants of the breached ridges stand 3 m above modern sea level, and ridges seaward of the breaches rise 2.2–3.0 m high. The overwash probably exceeded those heights when cutting the breaches by overtopping and incision of the beach ridges. Much of the sand-and-shell sheet contains pink bioclastic sand that resembles, in grain size and composition, the sand of the breached ridges. This sand extends as much as 1.5 km to the south of the breached ridges. It tapers southward from a maximum thickness of 40 cm, decreases in estimated mean grain size from medium sand to very fine sand, and contains mud laminae in the south. The sand-and-shell sheet also contains mollusks—cerithid gastropods and the bivalve Anomalocardia—and angular limestone granules and pebbles. The mollusk shells and the lime-mud cap were probably derived from a marine pond that occupied much of Anegada’s interior at the time of overwash. The boulders and cobbles, nearly all composed of limestone, form fields that extend many tens of meters generally southward from limestone outcrops as much as 0.8 km from the nearest shore. Soon after the inferred overwash, the marine pond was replaced by hypersaline ponds that produce microbial mats and evaporite crusts. This environmental change, which has yet to be reversed, required restriction of a former inlet or inlets, the location of which was probably on the island’s south (lee) side. The inferred overwash may have caused restriction directly by washing sand into former inlets, or indirectly by reducing the tidal prism or supplying sand to post-overwash currents and waves. The overwash happened after A.D. 1650 if coeval with radiocarbon-dated leaves in the mud cap, and it probably happened before human settlement in the last decades of the 1700s. A prior overwash event is implied by an inland set of breaches. Hypothetically, the overwash in 1650–1800 resulted from the Antilles tsunami of 1690, the transatlantic Lisbon tsunami of 1755, a local tsunami not previously documented, or a storm whose effects exceeded those of Hurricane Donna, which was probably at category 3 as its eye passed 15 km to Anegada’s south in 1960.

Description: The work was supported in part by the Nuclear Regulatory Commission under its project N6480, a tsunami-hazard assessment for the eastern United States.

Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecosystems 16 (2013): 1550-1564, doi:10.1007/s10021-013-9701-0.

Description: We examined controls of benthic dinitrogen (N2) fixation and primary production in oligotrophic lakes in Arctic Alaska, Toolik Field Station (Arctic Long-Term Ecological Research Site). Primary production in many oligotrophic lakes is limited by nitrogen (N), and benthic processes are important for whole-lake function. Oligotrophic lakes are increasingly susceptible to low-level, non-point source nutrient inputs, yet the effects on benthic processes are not well understood. This study examines the results from a whole-lake fertilization experiment in which N and P were added at a relatively low level (4 times natural loading) in Redfield ratio to a shallow (3 m) and a deep (20 m) oligotrophic lake. The two lakes showed similar responses to fertilization: benthic primary production and respiration (each 50–150 mg C m−2 day−1) remained the same, and benthic N2 fixation declined by a factor of three- to fourfold by the second year of treatment (from ~0.35 to 0.1 mg N m−2 day−1). This showed that the response of benthic N2 fixation was de-coupled from the nutrient limitation status of benthic primary producers and raised questions about the mechanisms, which were examined in separate laboratory experiments. Bioassay experiments in intact cores also showed no response of benthic primary production to added N and P, but contrasted with the whole-lake experiment in that N2 fixation did not respond to added N, either alone or in conjunction with P. This inconsistency was likely a result of nitrogenase activity of existing N2 fixers during the relative short duration (9 days) of the bioassay experiment. N2 fixation showed a positive saturating response when light was increased in the laboratory, but was not statistically related to ambient light level in the field, leading us to conclude that light limitation of the benthos from increasing water-column production was not important. Thus, increased N availability in the sediments through direct uptake likely caused a reduction in N2 fixation. These results show the capacity of the benthos in oligotrophic systems to buffer the whole-system response to nutrient addition by the apparent ability for significant nutrient uptake and the rapid decline in N2 fixation in response to added nutrients. Reduced benthic N2 fixation may be an early indicator of a eutrophication response of lakes which precedes the transition from benthic to water-column-dominated systems.

Description: This project was supported by NSF-OPP 9732281, NSF-DEB 9810222, NSF-DEB 0423385, and by a Doctoral Dissertation Improvement Grant NSF-DEB 0206173. Additional funding was provided by the Small Grants Program through the NSF-IGERT Program in Biogeochemistry and Environmental Change at Cornell University.

Description: © The Author(s), 2010. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Theoretical Ecology 5 (2012): 167-179, doi:10.1007/s12080-010-0106-9.

Description: Studies of time-invariant matrix metapopulation models indicate that metapopulation growth rate is usually more sensitive to the vital rates of individuals in high-quality (i.e., good) patches than in low-quality (i.e., bad) patches. This suggests that, given a choice, management efforts should focus on good rather than bad patches. Here, we examine the sensitivity of metapopulation growth rate for a two-patch matrix metapopulation model with and without stochastic disturbance and found cases where managers can more efficiently increase metapopulation growth rate by focusing efforts on the bad patch. In our model, net reproductive rate differs between the two patches so that in the absence of dispersal, one patch is high quality and the other low quality. Disturbance, when present, reduces net reproductive rate with equal frequency and intensity in both patches. The stochastic disturbance model gives qualitatively similar results to the deterministic model. In most cases, metapopulation growth rate was elastic to changes in net reproductive rate of individuals in the good patch than the bad patch. However, when the majority of individuals are located in the bad patch, metapopulation growth rate can be most elastic to net reproductive rate in the bad patch. We expand the model to include two stages and parameterize the patches using data for the softshell clam, Mya arenaria. With a two-stage demographic model, the elasticities of metapopulation growth rate to parameters in the bad patch increase, while elasticities to the same parameters in the good patch decrease. Metapopulation growth rate is most elastic to adult survival in the population of the good patch for all scenarios we examine. If the majority of the metapopulation is located in the bad patch, the elasticity to parameters of that population increase but do not surpass elasticity to parameters in the good patch. This model can be expanded to include additional patches, multiple stages, stochastic dispersal, and complex demography.

Description: Financial support was provided by the Woods Hole Oceanographic Institution Academic Programs Office; National Science Foundation grants OCE-0326734, OCE- 0215905, OCE-0349177, DEB-0235692, DEB-0816514, DMS- 0532378, OCE-1031256, and ATM-0428122; and by National Oceanic and Atmospheric Administration National Sea Grant College Program Office, Department of Commerce, under Grant No. NA86RG0075 (Woods Hole Oceanographic Institution Sea Grant Project No. R/0-32), and Grant No. NA16RG2273 (Woods Hole Oceanographic Institution Sea Grant Project No. R/0-35).

Description: © The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estuaries and Coasts 35 (2012): 401-415, doi:10.1007/s12237-011-9417-3.

Description: Although the Arctic Ocean is the most riverine-influenced of all of the world’s oceans, the importance of terrigenous nutrients in this environment is poorly understood. This study couples estimates of circumpolar riverine nutrient fluxes from the PARTNERS (Pan-Arctic River Transport of Nutrients, Organic Matter, and Suspended Sediments) Project with a regionally configured version of the MIT general circulation model to develop estimates of the distribution and availability of dissolved riverine N in the Arctic Ocean, assess its importance for primary production, and compare these estimates to potential bacterial production fueled by riverine C. Because riverine dissolved organic nitrogen is remineralized slowly, riverine N is available for uptake well into the open ocean. Despite this, we estimate that even when recycling is considered, riverine N may support 0.5–1.5 Tmol C year−1 of primary production, a small proportion of total Arctic Ocean photosynthesis. Rapid uptake of dissolved inorganic nitrogen coupled with relatively high rates of dissolved organic nitrogen regeneration in N-limited nearshore regions, however, leads to potential localized rates of riverine-supported photosynthesis that represent a substantial proportion of nearshore production.

Description: Funding for this work was provided through NSFOPP- 0229302 and NSF-OPP-0732985.Support to SET was additionally provided by an NSERC Postdoctoral Fellowship.

Description: This paper is not subject to U.S. copyright. The definitive version was published in Ecosystems 15 (2012): 848-866, doi:10.1007/s10021-012-9551-1.

Description: Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland losses. However, ecosystem development and functional equivalence in restored and created mangrove wetlands are poorly understood. We compared a 20-year chronosequence of created tidal wetland sites in Tampa Bay, Florida (USA) to natural reference mangrove wetlands. Across the chronosequence, our sites represent the succession from salt marsh to mangrove forest communities. Our results identify important soil and plant structural differences between the created and natural reference wetland sites; however, they also depict a positive developmental trajectory for the created wetland sites that reflects tightly coupled plant-soil development. Because upland soils and/or dredge spoils were used to create the new mangrove habitats, the soils at younger created sites and at lower depths (10–30 cm) had higher bulk densities, higher sand content, lower soil organic matter (SOM), lower total carbon (TC), and lower total nitrogen (TN) than did natural reference wetland soils. However, in the upper soil layer (0–10 cm), SOM, TC, and TN increased with created wetland site age simultaneously with mangrove forest growth. The rate of created wetland soil C accumulation was comparable to literature values for natural mangrove wetlands. Notably, the time to equivalence for the upper soil layer of created mangrove wetlands appears to be faster than for many other wetland ecosystem types. Collectively, our findings characterize the rate and trajectory of above- and below-ground changes associated with ecosystem development in created mangrove wetlands; this is valuable information for environmental managers planning to sustain existing mangrove wetlands or mitigate for mangrove wetland losses.

Description: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Biology 159 (2012): 1833-1841, doi:10.1007/s00227-012-1973-y.

Description: The mesopelagic zone of the Red Sea represents an extreme environment due to low food concentrations, high temperatures and low oxygen waters. Nevertheless, a 38 kHz echosounder identified at least four distinct scattering layers during the daytime, of which the 2 deepest layers resided entirely within the mesopelagic zone. Two of the acoustic layers were found above a mesopelagic oxygen minimum zone (OMZ), one layer overlapped with the OMZ, and one layer was found below the OMZ. Almost all organisms in the deep layers migrated to the near-surface waters during the night. Backscatter from a 300 kHz lowered Acoustic Doppler Current Profiler indicated a layer of zooplankton within the OMZ. They carried out DVM, yet a portion remained at mesopelagic depths during the night. Our acoustic measurements showed that the bulk of the acoustic backscatter was restricted to waters shallower than 800 m, suggesting that most of the biomass in the Red Sea resides above this depth.

Description: This research is based in part on work supported by Award Nos. USA 00002, KSA 00011 and KSA 00011/02 made by KAUST to the Woods Hole Oceanographic Institution.

Description: This paper is not subject to U.S. copyright. The definitive version was published in Geo-Marine Letters 32 (2012): 279-288, doi:10.1007/s00367-012-0296-9.

Description: High-resolution seismic-reflection profiles collected across pro-glacial outwash deposits adjacent to the circa 18 ka b.p. Orient Point–Fishers Island end moraine segment in westernmost Block Island Sound reveal extensive deformation. A rhythmic seismic facies indicates the host outwash deposits are composed of fine-grained glaciolacustrine sediments. The deformation is variably brittle and ductile, but predominantly compressive in nature. Brittle deformation includes reverse faults and thrust faults that strike parallel to the moraine, and thrust sheets that extend from beneath the moraine. Ductile deformation includes folded sediments that overlie undisturbed deposits, showing that they are not drape features. Other seismic evidence for compression along the ice front consists of undisturbed glaciolacustrine strata that dip back toward and underneath the moraine, and angular unconformities on the sea floor where deformed sediments extend above the surrounding undisturbed correlative strata. Together, these ice-marginal glaciotectonic features indicate that the Orient Point–Fishers Island moraine marks a significant readvance of the Laurentide ice sheet, consistent with existing knowledge for neighboring coeval moraines, and not simply a stillstand as previously reported.

Description: This work was supported by the Connecticut Department of Environmental Protection, and the Atlantic Hydrographic Branch of the National Oceanic and Atmospheric Administration.

Description: 2013-06-29

Description: This paper is not subject to U.S. copyright. The definitive version was published in Estuaries and Coasts 35 (2012): 1285-1298, doi:10.1007/s12237-012-9515-x.

Description: Increased nutrient loading to estuaries has led to eutrophication, degraded water quality, and ecological transformations. Quantifying nutrient loads in systems with significant groundwater input can be difficult due to the challenge of measuring groundwater fluxes. We quantified tidal and freshwater fluxes over an 8-week period at the entrance of West Falmouth Harbor, Massachusetts, a eutrophic, groundwater-fed estuary. Fluxes were estimated from velocity and salinity measurements and a total exchange flow (TEF) methodology. Intermittent cross-sectional measurements of velocity and salinity were used to convert point measurements to cross-sectionally averaged values over the entire deployment (index relationships). The estimated mean freshwater flux (0.19 m3/s) for the 8-week period was mainly due to groundwater input (0.21 m3/s) with contributions from precipitation to the estuary surface (0.026 m3/s) and removal by evaporation (0.048 m3/s). Spring–neap variations in freshwater export that appeared in shorter-term averages were mostly artifacts of the index relationships. Hydrodynamic modeling with steady groundwater input demonstrated that while the TEF methodology resolves the freshwater flux signal, calibration of the index– salinity relationships during spring tide conditions only was responsible for most of the spring–neap signal. The mean freshwater flux over the entire period estimated from the combination of the index-velocity, index–salinity, and TEF calculations were consistent with the model, suggesting that this methodology is a reliable way of estimating freshwater fluxes in the estuary over timescales greater than the spring– neap cycle. Combining this type of field campaign with hydrodynamic modeling provides guidance for estimating both magnitude of groundwater input and estuarine storage of freshwater and sets the stage for robust estimation of the nutrient load in groundwater.

Description: Funding was provided by the USGS Coastal and Marine Geology Program and by National Science Foundation Award #0420575 from the Biocomplexity/Coupled Biogeochemical Cycles Program.

Description: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeochemistry 114 (2013): 11-23, doi:10.1007/s10533-012-9801-5.

Description: Human actions have both intentionally and unintentionally altered the global economy of nitrogen (N), with both positive and negative consequences for human health and welfare, the environment and climate change. Here we examine long-term trends in reactive N (Nr) creation and efficiencies of Nr use within the continental US. We estimate that human actions in the US have increased Nr inputs by at least ~5 times compared to pre-industrial conditions. Whereas N2 fixation as a by-product of fossil fuel combustion accounted for ~1/4 of Nr inputs from the 1970s to 2000 (or ~7 Tg N year−1), this value has dropped substantially since then (to 〈5 Tg N year−1), owing to Clean Air Act amendments. As of 2007, national N use efficiency (NUE) of all combined N inputs was equal to ~40 %. This value increases to 55 % when considering intentional N inputs alone, with food, industrial goods, fuel and fiber production accounting for the largest Nr sinks, respectively. We estimate that 66 % of the N lost during the production of goods and services enters the air (as NO x , NH3, N2O and N2), with the remaining 34 % lost to various waterways. These Nr losses contribute to smog formation, acid rain, eutrophication, biodiversity declines and climate change. Hence we argue that an improved national NUE would: (i) benefit the US economy on the production side; (ii) reduce social damage costs; and (iii) help avoid some major climate change risks in the future.

Description: This work resulted from a workshop supported by NSF Research Coordination Network Awards DEB-0443439 and DEB-1049744 and by the David and Lucille Packard Foundation.

Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Conservation Genetics Resources 5 (2013): 561-563, doi:10.1007/s12686-012-9852-x.

Description: A total of one hundred microsatellites loci were selected from the draft genome of Stylophora pistillata and evaluated in previously characterized samples of Stylophora cf pistillata from the Red Sea. 17 loci were amplified successfully and tested in 24 individuals from samples belonging to a single population from the central region of the Red Sea. The number of alleles ranged from 3 to 15 alleles per locus, while observed heterozygosity ranged from 0.292 to 0.95. Six of these loci showed significant deviations from Hardy–Weinberg equilibrium (HWE) expectations, and 4/136 paired loci comparisons suggested linkage disequilibrium after Bonferroni corrections. After excluding loci with significant HWE deviation and evidence of null alleles, average genetic diversity over loci in the population studied (N = 24, Nloci = 11) was 0.701 ± 0.380. This indicates that these loci can be used effectively to evaluate genetic diversity and undertake population genetics studies in Stylophora sp. populations.

Description: This research was funded by King Abdullah University of Science and Technology (KAUST), Saudi Arabia.

Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeochemistry 115 (2013): 299-315, doi:10.1007/s10533-013-9836-2.

Description: A series of eight watersheds on the Pacific coast of Panama where conversion of mature lowland wet forest to pastures by artisanal burning provided watershed-scale experimental units with a wide range of forest cover (23, 29, 47, 56, 66, 73, 73, 91, and 92%). We used these watersheds as a landscape-scale experiment to assess effects of degree of deforestation on within-watershed retention and hydrological export of atmospheric inputs of nutrients. Retention was estimated by comparing rainfall nutrient concentrations (volume-weighted to allow for evapotranspiration) to concentrations in freshwater reaches of receiving streams. Retention of rain-derived nutrients in these Panama watersheds averaged 77, 85, 80, and 62% for nitrate, ammonium, dissolved organic N, and phosphate, respectively. Retention of rain-derived inorganic nitrogen, however, depended on watershed cover: retention of nitrate and ammonium in pasture-dominated watersheds was 95 and 98%, while fully forested watersheds retained 65 and 80% of atmospheric nitrate and ammonium inputs. Watershed forest cover did not affect retention of dissolved organic nitrogen and phosphate. Exports from more forested watersheds yielded DIN/P near 16, while pasture-dominated watersheds exported N/P near 2. The differences in magnitude of exports and ratios suggest that deforestation in these Panamanian forests results in exports that affect growth of plants and algae in the receiving stream and estuarine ecosystems. Watershed retention of dissolved inorganic nitrogen calculated from wet plus dry atmospheric deposition varied from 90% in pasture- to 65% in forest-dominated watersheds, respectively. Discharges of DIN to receiving waters from the watersheds therefore rose from 10% of atmospheric inputs for pasture-dominated watersheds, to about 35% of atmospheric inputs for fully forested watersheds. These results from watersheds with no agriculture or urbanization, but different conversion of forest to pasture by burning, show significant, deforestation-dependent retention within tropical watersheds, but also ecologically significant, and deforestation-dependent, exports that are biologically significant because of the paucity of nutrients in receiving tropical stream and coastal waters.

Description: This work was funded by NSF Grant BIO- 0842413

Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Climatic Change 121 (2013): 381-395, doi:10.1007/s10584-013-0873-6.

Description: Anthropogenic climate change has triggered impacts on natural and human systems world-wide, yet the formal scientific method of detection and attribution has been only insufficiently described. Detection and attribution of impacts of climate change is a fundamentally cross-disciplinary issue, involving concepts, terms, and standards spanning the varied requirements of the various disciplines. Key problems for current assessments include the limited availability of long-term observations, the limited knowledge on processes and mechanisms involved in changing environmental systems, and the widely different concepts applied in the scientific literature. In order to facilitate current and future assessments, this paper describes the current conceptual framework of the field and outlines a number of conceptual challenges. Based on this, it proposes workable cross-disciplinary definitions, concepts, and standards. The paper is specifically intended to serve as a baseline for continued development of a consistent cross-disciplinary framework that will facilitate integrated assessment of the detection and attribution of climate change impacts.

Description: Modeling Program of the Office of Biological and Environmental Research in the Department of Energy Office of Science under contract number DE-AC02-05CH11231. GH was supported by a grant from the German Ministry for Education and Research.

Description: © The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution-Noncommercial License. The definitive version was published in Ecosystems 13 (2010): 239-248, doi:10.1007/s10021-010-9315-8.

Description: Ecosystem nutrient budgets often report values for pools and fluxes without any indication of uncertainty, which makes it difficult to evaluate the significance of findings or make comparisons across systems. We present an example, implemented in Excel, of a Monte Carlo approach to estimating error in calculating the N content of vegetation at the Hubbard Brook Experimental Forest in New Hampshire. The total N content of trees was estimated at 847 kg ha−1 with an uncertainty of 8%, expressed as the standard deviation divided by the mean (the coefficient of variation). The individual sources of uncertainty were as follows: uncertainty in allometric equations (5%), uncertainty in tissue N concentrations (3%), uncertainty due to plot variability (6%, based on a sample of 15 plots of 0.05 ha), and uncertainty due to tree diameter measurement error (0.02%). In addition to allowing estimation of uncertainty in budget estimates, this approach can be used to assess which measurements should be improved to reduce uncertainty in the calculated values. This exercise was possible because the uncertainty in the parameters and equations that we used was made available by previous researchers. It is important to provide the error statistics with regression results if they are to be used in later calculations; archiving the data makes resampling analyses possible for future researchers. When conducted using a Monte Carlo framework, the analysis of uncertainty in complex calculations does not have to be difficult and should be standard practice when constructing ecosystem budgets.

Description: © The Authors 2009. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Biogeochemistry 99 (2010): 1-13, doi:10.1007/s10533-009-9392-y.

Description: Human activities have profoundly altered the global nitrogen (N) cycle. Increases in anthropogenic N have had multiple effects on the atmosphere, on terrestrial, freshwater and marine ecosystems, and even on human health. Unfortunately, methodological limitations challenge our ability to directly measure natural N inputs via biological N fixation (BNF)—the largest natural source of new N to ecosystems. This confounds efforts to quantify the extent of anthropogenic perturbation to the N cycle. To address this gap, we used a pair of indirect methods—analytical modeling and N balance—to generate independent estimates of BNF in a presumed hotspot of N fixation, a tropical rain forest site in central Rondônia in the Brazilian Amazon Basin. Our objectives were to attempt to constrain symbiotic N fixation rates in this site using indirect methods, and to assess strengths and weaknesses of this approach by looking for areas of convergence and disagreement between the estimates. This approach yielded two remarkably similar estimates of N fixation. However, when compared to a previously published bottom-up estimate, our analysis indicated much lower N inputs via symbiotic BNF in the Rondônia site than has been suggested for the tropics as a whole. This discrepancy may reflect errors associated with extrapolating bottom-up fluxes from plot-scale measures, those resulting from the indirect analyses, and/or the relatively low abundance of legumes at the Rondônia site. While indirect methods have some limitations, we suggest that until the technological challenges of directly measuring N fixation are overcome, integrated approaches that employ a combination of model-generated and empirically-derived data offer a promising way of constraining N inputs via BNF in natural ecosystems.

Description: We acknowledge and are grateful for financial support from the Andrew W. Mellon Foundation (C.C. and B.H.), the National Science Foundation (NSF DEB-0515744 to C.C. and A.T. and DEB-0315656 to C.N.), and the NASA LBA Program (NCC5-285 to C.N.).

Description: © The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Theoretical Ecology 5 (2012): 403-417, doi:10.1007/s12080-011-0132-2.

Description: Matrix population models in which individuals are classified by both age and stage can be constructed using the vec-permutation matrix. The resulting age-stage models can be used to derive the age-specific consequences of a stage-specific life history or to describe populations in which the vital rates respond to both age and stage. I derive a general formula for the sensitivity of any output (scalar, vector, or matrix-valued) of the model, to any vector of parameters, using matrix calculus. The matrices describing age-stage dynamics are almost always reducible; I present results giving conditions under which population growth is ergodic from any initial condition. As an example, I analyze a published stage-specific model of Scotch broom (Cytisus scoparius), an invasive perennial shrub. Sensitivity analysis of the population growth rate finds that the selection gradients on adult survival do not always decrease with age but may increase over a range of ages. This may have implications for the evolution of senescence in stage-classified populations. I also derive and analyze the joint distribution of age and stage at death and present a sensitivity analysis of this distribution and of the marginal distribution of age at death.

Description: This research was supported by National Science Foundation Grant DEB-0816514 and by a Research Award from the Alexander von Humboldt Foundation.

Description: © The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Biological Invasions 13 (2011): 2513-2531, doi:10.1007/s10530-011-0078-8.

Description: The spiny water flea (Bythotrephes longimanus) is spreading from Great Lakes coastal waters into northern inland lakes within a northern temperature-defined latitudinal band. Colonization of Great Lakes coastal embayments is assisted by winds and seiche surges, yet rapid inland expansion across the northern states comes through an overland process. The lack of invasions at Isle Royale National Park contrasts with rapid expansion on the nearby Keweenaw Peninsula. Both regions have comparable geology, lake density, and fauna, but differ in recreational fishing boat access, visitation, and containment measures. Tail spines protect Bythotrephes against young of the year, but not larger fish, yet the unusual thick-shelled diapausing eggs can pass through fish guts in viable condition. Sediment traps illustrate how fish spread diapausing eggs across lakes in fecal pellets. Trillions of diapausing eggs are produced per year in Lake Michigan and billions per year in Lake Michigamme, a large inland lake. Dispersal by recreational fishing is linked to use of baitfish, diapausing eggs defecated into live wells and bait buckets, and Bythothephes snagged on fishing line, anchor ropes, and minnow seines. Relatively simple measures, such as on-site rinsing of live wells, restricting transfer of certain baitfish species, or holding baitfish for 24 h (defecation period), should greatly reduce dispersal.

Description: Study of Lakes Superior and Michigan was funded from NSF OCE-9726680 and OCE-9712872 to W.C.K., OCE-9712889 to J. Churchill. Geographic survey sampling and Park studies in the national parks during 2008-2010 were funded by a grant from the National Park Service Natural Resource Preservation Program GLNF CESU Task Agreement No. J6067080012.

Description: © The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Oecologia 168 (2012): 819-828, doi:10.1007/s00442-011-2133-7.

Description: Global climate change is expected to affect terrestrial ecosystems in a variety of ways. Some of the more well-studied effects include the biogeochemical feedbacks to the climate system that can either increase or decrease the atmospheric load of greenhouse gases such as carbon dioxide and nitrous oxide. Less well-studied are the effects of climate change on the linkages between soil and plant processes. Here, we report the effects of soil warming on these linkages observed in a large field manipulation of a deciduous forest in southern New England, USA, where soil was continuously warmed 5°C above ambient for 7 years. Over this period, we have observed significant changes to the nitrogen cycle that have the potential to affect tree species composition in the long term. Since the start of the experiment, we have documented a 45% average annual increase in net nitrogen mineralization and a three-fold increase in nitrification such that in years 5 through 7, 25% of the nitrogen mineralized is then nitrified. The warming-induced increase of available nitrogen resulted in increases in the foliar nitrogen content and the relative growth rate of trees in the warmed area. Acer rubrum (red maple) trees have responded the most after 7 years of warming, with the greatest increases in both foliar nitrogen content and relative growth rates. Our study suggests that considering species-specific responses to increases in nitrogen availability and changes in nitrogen form is important in predicting future forest composition and feedbacks to the climate system.

Description: This work was supported by the National Institute for Climate Change Research (DOE-DE-FCO2-06-ER64157), DOE BER (DE-SC0005421) and the Harvard Forest Long-Term Ecological Research program (NSF-DEB-0620443).

Description: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estuaries and Coasts 35 (2012): 1036-1048, doi:10.1007/s12237-012-9501-3.

Description: We used high-resolution in situ measurements of turbidity and fluorescent dissolved organic matter (FDOM) to quantitatively estimate the tidally driven exchange of mercury (Hg) between the waters of the San Francisco estuary and Browns Island, a tidal wetland. Turbidity and FDOM—representative of particle-associated and filter-passing Hg, respectively—together predicted 94 % of the observed variability in measured total mercury concentration in unfiltered water samples (UTHg) collected during a single tidal cycle in spring, fall, and winter, 2005–2006. Continuous in situ turbidity and FDOM data spanning at least a full spring-neap period were used to generate UTHg concentration time series using this relationship, and then combined with water discharge measurements to calculate Hg fluxes in each season. Wetlands are generally considered to be sinks for sediment and associated mercury. However, during the three periods of monitoring, Browns Island wetland did not appreciably accumulate Hg. Instead, gradual tidally driven export of UTHg from the wetland offset the large episodic on-island fluxes associated with high wind events. Exports were highest during large spring tides, when ebbing waters relatively enriched in FDOM, dissolved organic carbon (DOC), and filter-passing mercury drained from the marsh into the open waters of the estuary. On-island flux of UTHg, which was largely particle-associated, was highest during strong winds coincident with flood tides. Our results demonstrate that processes driving UTHg fluxes in tidal wetlands encompass both the dissolved and particulate phases and multiple timescales, necessitating longer term monitoring to adequately quantify fluxes.

Description: This work was supported by funding from the California Bay Delta Authority Ecosystem Restoration and Drinking Water Programs (grant ERP-00- G01) and matching funds from the United States Geological Survey Cooperative Research Program.

Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Reviews in Fish Biology and Fisheries 23 (2013): 317-364, doi:10.1007/s11160-012-9297-z.

Description: A recent survey lists more than 100 papers utilizing the auditory evoked potential (AEP) recording technique for studying hearing in fishes. More than 95 % of these AEP-studies were published after Kenyon et al. introduced a non-invasive electrophysiological approach in 1998 allowing rapid evaluation of hearing and repeated testing of animals. First, our review compares AEP hearing thresholds to behaviorally gained thresholds. Second, baseline hearing abilities are described and compared in 111 fish species out of 51 families. Following this, studies investigating the functional significance of various accessory hearing structures (Weberian ossicles, swim bladder, otic bladders) by eliminating these morphological structures in various ways are dealt with. Furthermore, studies on the ontogenetic development of hearing are summarized. The AEP-technique was frequently used to study the effects of high sound/noise levels on hearing in particular by measuring the temporary threshold shifts after exposure to various noise types (white noise, pure tones and anthropogenic noises). In addition, the hearing thresholds were determined in the presence of noise (white, ambient, ship noise) in several studies, a phenomenon termed masking. Various ecological (e.g., temperature, cave dwelling), genetic (e.g., albinism), methodical (e.g., ototoxic drugs, threshold criteria, speaker choice) and behavioral (e.g., dominance, reproductive status) factors potentially influencing hearing were investigated. Finally, the technique was successfully utilized to study acoustic communication by comparing hearing curves with sound spectra either under quiet conditions or in the presence of noise, by analyzing the temporal resolution ability of the auditory system and the detection of temporal, spectral and amplitude characteristics of conspecific vocalizations.

Description: Support from the Austrian Science Fund (FWF grant 22319 to F.L.).

Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Biodiversity 43 (2013): 237-241, doi:10.1007/s12526-013-0151-x.

Description: Despite the ubiquitous role sponges play in reef ecosystem dynamics, little is known about population-level connectivity in these organisms. The general field of population genetics in sponges remains in its infancy. To date, microsatellite markers have only been developed for few sponge species and no sponge population genetics studies using microsatellites have been conducted in the Red Sea. Here, with the use of next-generation sequencing, we characterize 12 novel polymorphic loci for the common reef sponge, Stylissa carteri. The number of alleles per loci ranged between three and eight. Observed heterozygosity frequencies (Ho) ranged from 0.125 to 0.870, whereas expected (He) heterozygosity frequencies ranged from 0.119 to 0.812. Only one locus showed consistent deviations from Hardy-Weinberg equilibrium (HWE) in both populations and two loci consistently showed the possible presence of null alleles. No significant linkage disequilibrium was detected for any pairs of loci. These microsatellites will be of use for numerous ecological studies focused on this common and abundant sponge.

Description: This work was funded by the King Abdullah University of Science and Technology.

Description: The South Atlantic magnetic Anomaly (SAA) is an important feature of the present geomagnetic field. In this paper we model the space–time evolution of this anomaly over the past 400 years in terms of the resultant between a decrease of a global axial dipole and an increase of a virtual local monopole source. Certain characteristics of this evolution are investigated and some considerations are made in the light of a possible special state of the global geomagnetic field dynamical regime. Among the possible speculations, one is made regarding the topography of the coremantle boundary (CMB) and its possible aspect beneath the SAA region in terms of simple sinusoidal undulations met by the monopole source during its centennial motion.

Description: Published

Description: 339-347

Description: 3.4. Geomagnetismo

Description: JCR Journal

Description: reserved

Description: Understanding the historical and future response of the global climate system to anthropogenic emissions of radiatively active atmospheric constituents has become a timely and compelling concern. At present, however, there are uncertainties in: the total radiative forcing associated with changes in the chemical composition of the atmosphere; the effective forcing applied to the climate system resulting from a (temporary) reduction via ocean-heat uptake; and the strength of the climate feedbacks that subsequently modify this forcing. Here a set of analyses derived from atmospheric general circulation model simulations are used to estimate the effective and total radiative forcing of the observed climate system due to anthropogenic emissions over the last 50 years of the twentieth century. They are also used to estimate the sensitivity of the observed climate system to these emissions, as well as the expected change in global surface temperatures once the climate system returns to radiative equilibrium. Results indicate that estimates of the effective radiative forcing and total radiative forcing associated with historical anthropogenic emissions differ across models. In addition estimates of the historical sensitivity of the climate to these emissions differ across models. However, results suggest that the variations in climate sensitivity and total climate forcing are not independent, and that the two vary inversely with respect to one another. As such, expected equilibrium temperature changes, which are given by the product of the total radiative forcing and the climate sensitivity, are relatively constant between models, particularly in comparison to results in which the total radiative forcing is assumed constant. Implications of these results for projected future climate forcings and subsequent responses are also discussed.

Description: Published

Description: 1461-1475

Description: 3.7. Dinamica del clima e dell'oceano

Description: JCR Journal

Description: open

Description: In this paper, a high-resolution digital elevation model (DEM) of the Ischia Island has been created, and a digital terrain analysis has been carried out to identify of morphostructural elements of this landscape. Ischia is an active volcano located in the Western sector of the Gulf of Naples that is characterized by historical and recent volcano-tectonic activity. The local kinematics is unclear, and so identification of tectonic lineaments might elucidate recent tectonic processes. We identify morphostructural features using geomorphic parameters derived from analysis of the high-resolution DEM. Successively, the comparison with known geologic features provides validation of the extracted morphotectonic data.We found that one of the main directions of the morphostructural lineaments extracted is consistent with the regional NE–SW extensional stress field; moreover, the lineaments on the northern flank of Mt. Epomeo are strictly correlated with the mapped faults that have a history of strong and moderate earthquakes. The technique implemented for this study area allowed us to identify new original morphostructural lineaments in a reproducible way that may be useful for investigating various landscapes where field survey is not possible. Indeed, the extracted lineaments represent potential active faults near the northern coast of the Ischia Island, where both seismicity and intense urbanization delineate a high seismic risk.

Description: Published

Description: 73-82

Description: 3.2. Tettonica attiva

Description: N/A or not JCR

Description: reserved

Description: Destructive volcaniclastic flows are among the most recurrent and dangerous natural phenomena in volcanic areas. They can originate not only during or shortly after an eruption (syn-eruptive) but also during a period of volcanic quiescence (inter-eruptive), when heavy and/or persistent rains remobilize loose pyroclastic deposits. The area in Italy most prone to such flows is that of the Apennine Mountains bordering the southern Campania Plain. These steep slopes are covered by pyroclastic material of variable thickness (a few cm to several m) derived from the explosive activity of the Somma-Vesuvius and Campi Flegrei volcanoes a few tens of kilometers to the west. The largest and most recent devastating event occurred on May 5, 1998, causing the death of more than 150 people and considerable damage to villages at the foot of the Apennine Mountains. This tragic event was only the most recent of a number of volcaniclastic flows affecting the area in both historical and prehistoric times. Historical accounts report that more than 500 events have occurred in the last five centuries and that more than half of these occurred in the last 100 years, causing hundreds of deaths. In order to improve volcaniclastic flow hazard zonation and risk mitigation in the study area, we produced a zonation map that identifies the drainage basins potentially prone to disruption. This map was obtained by combining morphological characteristics (concavity and basin shape factor) and the mean slope distribution of drainage basins derived from a digital elevation model with a 10-m resolution. These parameters allowed for the classification of 1,069 drainage basins, which have been grouped into four different classes of proneness to disruption: low, moderate, high and very high. The map compiled in a GIS environment, as well as the linked database, can be rapidly queried.

Description: Published

Description: 371-387

Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi

Description: 4.3. TTC - Scenari di pericolosità vulcanica

Description: JCR Journal

Description: reserved

Description: We describe analytical details and uncertainty evaluation of a simple technique for the measurement of the carbon isotopic composition of CO2 in volcanic plumes. Data collected at Solfatara and Vulcano, where plumes are fed by fumaroles which are accessible for direct sampling, were first used to validate the technique. For both volcanoes, the plume-derived carbon isotopic compositions are in good agreement with the fumarolic compositions, thus providing confidence on the method, and allowing its application at volcanoes where the volcanic component is inaccessible to direct sampling. As a notable example, we applied the same method to Mount Etna where we derived a δ13C of volcanic CO2 between −0.9 ± 0.27‰ and −1.41 ± 0.27‰ (Bocca Nuova and Voragine craters). The comparison of our measurements to data reported in previous work highlights a temporal trend of systematic increase of δ13C values of Etna CO2 from ~ −4‰, in the 1970’s and the 1980’s, to ~ −1‰ at the present time (2009). This shift toward more positive δ13C values matches a concurrent change in magma composition and an increase in the eruption frequency and energy. We discuss such variations in terms of two possible processes: magma carbonate assimilation and carbon isotopic fractionation due to magma degassing along the Etna plumbing system. Finally, our results highlight potential of systematic measurements of the carbon isotopic composition of the CO2 emitted by volcanic plumes for a better understanding of volcanic processes and for improved surveillance of volcanic activity.

Description: In press

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: JCR Journal

Description: reserved

Description: The development of the new Italian strong-motion database ITACA (ITalian AC-celerometric Archive, http://itaca.mi.ingv.it) is in progress under the sponsorship of the National Department of Civil Protection (DPC) within Project S4, in the framework of DPC-INGV 2007–2009 research agreement. This work started from the alpha version of ITACA [8], where 2,182 3-component records from 1,004 earthquakes, mainly recorded by the National Accelerometric Network, RAN, operated by DPC, were processed and included in the database. Earthquake metadata, recording station information and reports on the available geologicalgeophysical information of 452 recording sites, corresponding to about 70% of the total, were also included. Subsequently, ITACA has been updated and will reach its final stage by the end of Project S4, around mid-2010, with additional features, improved information about recording stations, and updated records, including the Mw6.3 L’Aquila earthquake. All records were re-processed with respect to the alpha version [9], with a special care to preserve information about late-triggered events and to ensure compatibility of corrected records, i.e., velocity and displacement traces obtained by the first and second integral of the corrected acceleration should not be affected by unrealistic trends. After a short introduction of ITACA and its most relevant features and statistics, this paper mainly deals with the newly adopted processing scheme, with reference to the problems encountered and the solutions that have been devised.

Description: Published

Description: 99-114

Description: 5.2. TTC - Banche dati di sismologia strumentale

Description: open

Description: Italy is a country characterized by high seismic hazard so strong-motion monitoring represents a relevant issue. Several strong-motion networks have been installed in the Italian territory during the last decades, with the aim of recording the ground motion generated by moderate to strong events or to monitor single regions. The collection of the strong-motion recordings of the Italian earthquakes was recently fulfilled and data are distributed through the ITACA database (http://itaca.mi.ingv.it). The new data set was used to develop a set of ground motion prediction equations (hereinafter GMPEs) for the Italian territory (Bindi et al., 2009), in order to update the well known GMPEs developed by Sabetta and Pugliese. The recent Mw 6.3 earthquake that occurred in central Italy on April 2009 and the upgrades of the ITACA database gave us the possibility to validate the predictive capability of the newly developed GMPEs and to explore the regional variability inside the Italian territory.

Description: Published

Description: 53-70

Description: 4.1. Metodologie sismologiche per l'ingegneria sismica

Description: reserved

Description: In this paper, in an attempt to reveal possible changes connected to natural or anthropogenic causes, the main results of hydrogeochemical monitoring carried out at Mount Etna are evaluated. We report on the salinity contents of the groundwaters that flow in fractured volcanics, which make up the flanks of the volcano. These waters, analyzed for major ion chemistry, were sampled regularly from 1994 to 2004. Basing on nonparametric Sen’s slope estimator, time series of groundwater composition reveal that the salinity of most of the Etnean aquifers increased by 0.5% to 3.5% each year during this period. This change in the water chemistry is clearly referable to the overexploitation of the aquifers. This increasing trend needs to be inverted urgently; otherwise, it will cause a shortage of water in the near future, because the maximum admissible concentration of salinity for drinking water will be exceeded.

Description: Published

Description: 431-446

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: JCR Journal

Description: restricted

Description: The Mw 5.7 earthquake that occurred on 12 May 1802 is the only one with Mw ≥ 5.5 located west of Lake Garda in the central-northern part of the Po Plain, Northern Italy, and the strongest event located in the seismic zone 907 of the ZS9 seismogenic zonation of Italy. Current parametric earthquake catalogs locate the event not far from important cities (e.g., Milan) and to sites where nuclear power plants were to be built in the 1980s or could be built in a near future. Although the earthquake parameters seemed sufficiently well constrained, a detailed investigation of documentary sources was performed, in repositories storing the documents of the Napoleonic departments to which the area affected by the earthquake belonged at that time. In the surviving archival series, we found the officers’ correspondence on all the administrative aspects raised by the earthquake. The newly collected records allowed the authors to significantly increase the number of macroseismic intensity data, including new observations in the most damaged area. The results have been then interpreted in terms of both Mercalli–Cancani–Sieberg and EMS98 macroseismic scales. The earthquake parameters were derived applying two different methods in order to get two independent estimates. Earthquake location is confirmed, although the still scarce data available in the area to the east of the epicenter do not permit to reduce the uncertainty to a minimum. According to the Boxer method, the magnitude is now slightly higher, and the source model shows a good agreement with the tectonic setting of the area.

Description: Published

Description: 629-651

Description: 3.10. Storia ed archeologia applicate alle Scienze della Terra

Description: JCR Journal

Description: reserved

Description: On 30 December 2002, a 25-30 × 106 m3 landslide on the NW flank of Stromboli volcano produced a tsunami that caused relevant damage to the Stromboli village and to the neighboring islands of the Aeolian archipelago. The NW flank of Stromboli has been the site of several, cubic kilometer-scale, landslides during the past 13 ka. In this paper we present sedimentological and compositional data of deep-sea cores recovered from a site located about 24 km north of the island. Our preliminary results indicate that: (i) turbidity currents were effectively generated by the large-scale failures and (ii) volcanogenic turbidity current deposits retain clues of the landslide source and slope failure dynamics. By analogy with Hawaii and the Canary islands we confirm that deep-sea sediments can be effectively used to assess the age and scale of past landslide events giving an important contribution to the tsunami hazard assessment of this region.

Description: Published

Description: 719-731

Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi

Description: 4.3. TTC - Scenari di pericolosità vulcanica

Description: reserved

Description: Large variations of the CO2 flux through the soil were observed between November 2002 and January 2006 at Mt. Etna volcano. In many cases, the CO2 flux was strongly influenced by changes in air temperature and atmospheric pressure. A new filtering method was then developed to remove the atmospheric influences on soil CO2 flux and, at the same time, to highlight the variations strictly related to volcanic activity. Successively, the CO2 corrected data were quantitatively compared with the spectral amplitude of the volcanic tremor by cross correlation function, cross-wavelet spectrum and wavelet coherence. These analyses suggested that the soil CO2 flux variations preceded those of volcanic tremor by about 50 days. Given that volcanic tremor is linked to the shallow (a few kilometer) magma dynamics and soil CO2 flux related to the deeper (*12 km b.s.l.) magma dynamics, the ‘‘delayed similarity’’ between the CO2 flux and the volcanic tremor amplitude was used to assess the average speed in the magma uprising into the crust, as about 170–260 mper day. Finally, the large amount of CO2 released before the onset of the 2004–2005 eruption indicated a deep ingression of new magma, which might have triggered such an eruption.

Description: Published

Description: 477–489

Description: 3.6. Fisica del vulcanismo

Description: JCR Journal

Description: reserved

Description: The AND-2A drillcore (Antarctic Drilling Program—ANDRILL) was successfully completed in late 2007 on the Antarctic continental margin (Southern McMurdo Sound, Ross Sea) with the aim of tracking ice proximal to shallow marine environmental fluctuations and to document the 20-Ma evolution of the Erebus Volcanic Province. Lava clasts and tephra layers from the AND-2A drillcore were investigated from a petrographic and stratigraphic point of view and analyzed by the 40Ar–39Ar laser technique in order to constrain the age model of the core and to gain information on the style and nature of sediment deposition in the Victoria Land Basin since Early Miocene. Ten out of 17 samples yielded statistically robust 40Ar–39Ar ages, indicating that the AND-2A drillcore recovered ≤230 m of Middle Miocene (∼128–358 m below sea floor, ∼11.5–16.0 Ma) and 〉780 m of Early Miocene (∼358–1093 m below sea floor, ∼16.0–20.1 Ma). Results also highlight a nearly continuous stratigraphic record from at least 358 m below sea floor down hole, characterized by a mean sedimentation rate of ∼19 cm/ka, possible oscillations of no more than a few hundreds of ka and a break within ∼17.5–18.1 Ma. Comparison with available data from volcanic deposits on land, suggests that volcanic rocks within the AND-2A core were supplied from the south, possibly with source areas closer to the drill site for the upper core levels, and from 358 m below sea floor down hole, with the “proto-Mount Morning” as the main source.

Description: Published

Description: 487-505

Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce

Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi

Description: JCR Journal

Description: reserved

Description: Recent stratigraphic studies at Vesuvius have revealed that, during the past 4,000 years, long lasting,moderate to low-intensity eruptions, associated with continuous or pulsating ash emission, have repeatedly occurred. The present work focuses on the AS1a eruption, the first of a series of ash-dominated explosive episodes which characterized the period between the two Subplinian eruptions of 472 AD and 1631 AD. The deposits of this eruption consist of an alternation of massive and thinly laminated ash layers and minor well sorted lapilli beds, reflecting the pulsatory injection into the atmosphere of variably concentrated ash-plumes alternating with Violent Strombolian stages. Despite its nearly constant chemical composition, the juvenile material shows variable external clast morphologies and groundmass textures, reflecting the fragmentation of a magma body with lateral and/or vertical gradients in both vesicularity and crystal content. Glass compositions and mineralogical assemblages indicate that the eruption was fed by rather homogeneous phonotephritic magma batches rising from a reservoir located at ~ 4 km (100 MPa) depth, with fluctuations between magma delivery and magma discharge. Using crystal size distribution (CSD) analyses of plagioclase and leucite microlites, we estimate that the transit time of the magma in the conduit was on the order of ~ 2 days, corresponding to an ascent rate of around 2× 10−2 ms−1. Accordingly, assuming a typical conduit diameter for this type of eruption, the minimum duration of the AS1a event is between about 1.5 and 6 years. Magma fragmentation occurred in an inertially driven regime that, in a magma with low viscosity and surface tension, can act also under conditions of slow ascent.

Description: In press

Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi

Description: JCR Journal

Description: reserved

Description: Etna’s 2001 basaltic lava flow provided a good example of the distal flow segment between the flow front and stable channel, across which the flow evolves from channel-contained to dispersed. This zone was mapped with meter precision using LIDAR data collected during 2004 and 2005. These data, supported by field mapping, show that the flow front comprised eight lobes each 10 to 20 m high. The flow front appears to have advanced not as a single unit, but as a series of lobes moving forward one lobe at a time. Primary lobes were centered on the channel axis and marginal lobes were off-axis. The lobes advanced as breakouts of low-yield-strength lava from the flow core of the stalled flow front. Marginal lobes were abandoned and contributed to marginal levees flanking the transitional channel. For Etna’s 2001 flow, the transitional channel is 140 m wide, 700 m long and fed a 240-m-long zone of dispersed flow; the change from stable to transitional channel occurred at a major reduction in slope. Above this, the stable channel is 5.2 km long, 55 to 105 m wide and bounded by 15- to 25-m-high levees, and the stable channel is located over a previous channel. In a final stage of activity, lava ponding at the break-in-slope that marks the terminus of the stable channel put pressure on the eastern levee, causing it to fail. Liberated lava then fed a final break-out to the east. Similar flow front-features occur at other volcanoes, indicating that similar processes are characteristic of dispersed flow zones.

Description: Published

Description: 119-127

Description: 1.10. TTC - Telerilevamento

Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi

Description: 3.6. Fisica del vulcanismo

Description: JCR Journal

Description: reserved

Description: In this work we present and discuss the results of ambient seismic noise analyses computed at four sites where seismic stations, managed by the INGV (Italian Institute for Geophysics and Vulcanology) and the DPC (Italian Department of Civil Protection), are installed inside buildings. The experiments were performed considering different types of installation: sensor located at the bottom of a school, directly installed on rock (case 1); sensor located at the bottom of a medieval fortress, built on an isolate hill, directly installed on rock (case 2); sensor installed on the foundations of a medieval fortress, built on an isolate hill (case 3); sensor installed on the foundations of a school, built on alluvial deposits (case 4). Since recent works proposed the use of spectral ratio techniques to study the dynamic characterization of buildings, ambient seismic-noise measurements were performed for each site close to the stations (at the base of the structures), at the top of the structures and outside the buildings. In order to check the source of vibrations both horizontal to vertical spectral ratio (HVNR) and standard spectral ratio (SSR) techniques were applied. For all stations the results from ambient seismic noise were compared to those obtained from earthquakes (HVSR). In order to detect preferential directions of amplification, for each site average HVNRs and HVSRs were computed considering one azimuth for each set of 5°. We obtain different results for different types of installation: in cases 1 and 2, where the sensors are directly installed on rock, the vibrations of the structure do not affect the noise measures performed close to the stations, which show flat HVNR in the whole frequency range: in both cases the eigenfrequency of the building is given by the HVNR calculated from the measures performed at the top of the structure. In cases 3 and 4, where the sensors are installed on the foundations of the considered structures, both the amplification peaks between 5 and 9 Hz (case 3) and between 5.5 and 7 Hz (case 4) include the contribution of the free oscillations of the buildings. In particular, in case 4, HVNRs performed outside building highlight possible soil–structure resonance effects in case of an earthquake.

Description: Published

Description: 723-738

Description: 4.1. Metodologie sismologiche per l'ingegneria sismica

Description: JCR Journal

Description: open

Description: The necessity of a dense network in Northern Italy started from the lack of available data after the occurrence of the 24th November 2004, Ml 5.2, Salò earthquake. Since 2006, many efforts have been made by the INGV (Italian National Institute for Geophysic and Vulcanology), Department of Milano-Pavia (hereinafter INGV MI-PV), to improve the strong-motion monitoring of the Northern Italy regions. This activity led to the installation of a strong-motion network composed by 20 accelerometers, 4 coupled with 20-bits Lennartz Mars88 recorders, 12 coupled with 24-bits Reftek 130 recorders and 4 coupled with 24-bits Gaia2 recorders. The network allow us to reduce, in the area under study, the average inter-distances between strong-motion stations from about 40 km (at November 2004) to 15 km. At present the network includes nine 6-channels stations where velocity sensors work together the strong-motion ones. The data transmission is assured by modem-gsm, with the exception of four stations that send data in real time through a TCP/IP protocol. In order to evaluate different site responses, the stations have been installed both in free field and near (or inside) public buildings, located in the center of small villages. From June 2006 to December 2008 a dataset of 94 events with local magnitude range from 0.7 to 5.1 has been collected. An ad hoc data-processing system have been created in order to provide, after each recorded event, engineering parameters such as peak ground acceleration (PGA) and velocity (PGV), response spectra (SA and PSV), Arias and Housner intensities. Data dissemination is achieved through the web site http://rais.mi.ingv.it, while the waveforms are distributed through the Italian strong motion database (http://itaca.mi.ingv.it).

Description: Published

Description: 1091-1104

Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale

Description: JCR Journal

Description: open

Description: The definition of the aftershocks sequence is still a debated topic. We here propose a study of the spatial and temporal variation of the earthquakes clustering and rate decay. We used five different seismic catalogues, characterized by specific spatial and magnitude ranges. They are respectively: world one, for a global analysis, Greek, Japanese, Californian and Italian regional catalogues in order to investigate different seismo-tectonic settings. A stacking procedure has been applied to characterize a typical sequence behavior and allowing the evaluation of changes over time intervals (

Description: Published

Description: 323-337

Description: 3.1. Fisica dei terremoti

Description: open

Description: A repeat station is a site whose position is AQ1 accurately known and where accurate measurements of the geomagnetic field vector are made at regular intervals in order to provide information about the secular variation of the geomagnetic field. In this chapter we begin by giving a brief history of the development of repeat station networks. We then describe the instruments used to make measurements at a repeat station. These include fixing the position of the station, finding the direction of true north and measuring the components of the geomagnetic field. Emphasis is given to techniques and instruments that are in current use. We next discuss the procedures that are used to reduce the measurements to a usable form and consider the uses to which the reduced data are put. Finally, we discuss the continued importance of such data in the present era of satellite geomagnetic surveys.

Description: Submitted

Description: In press

Description: 1.6. Osservazioni di geomagnetismo

Description: restricted

Description: Using the characteristic earthquake model, we calculate the probability of occurrence of earthquakes Mw 〉 5.5 for individual fault sources in the Central Apennines for the 30-year period (2007–2037). We show the effect of timedependent and time-independent occurrence (Brownian passage time (BPT) and Poisson) models together with uncertain slip rates and uncertain maximum magnitudes and, hence, uncertain recurrence times. In order to reduce the large prior geological slip rate uncertainty distribution for most faults, we obtain a posterior slip rate uncertainty distribution using a likelihood function obtained from regional historical seismicity. We assess the uncertainty of maximum magnitude by assuming that the uncertainty in fault width and length are described by a normal distribution with standard deviation equal to ±20% of the mean values. We then estimate the uncertainties of the 30-year probability of occurrence of a characteristic event using a Monte Carlo procedure. Uncertainty on each parameter is represented by the 16th and the 84th percentiles of simulated values. These percentiles bound the range that has a 68% probability of including the real value of the parameter. We do these both for the Poisson case and for the BPT case by varying the aperiodicity parameter (α value) using the values 0.3, 0.5, and 0.7. The Bayesian posterior slip rate uncertainties typically differ by a factor of about 2 from the 16th to the 84th percentile. Occurrence probabilities for the next 30 years at the 84th percentile typically range from 1% to 2% for faults where the Poisson model dominates and from 2% to 21% where one of the BPT models dominates. The uncertainty in occurrence probability under the time-dependent hypothesis is very large, when measured by the ratio of the 84th to the 16th percentile, frequently being as much as two orders of magnitude. On the other hand, when measured by standard deviation, these standard deviations range from 2% to 6% for those faults whose elapsed time since previous event is large, but always 2% or less for faults with relatively recent previous occurrence, because the probability of occurrence is always small.

Description: Published

Description: 95-117

Description: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale

Description: JCR Journal

Description: reserved

Description: Natural precipitation and water samples from passive devices were collected at Mt. Vesuvius and Vulcano Island, Italy, during the period 2004–2006, in order to investigate its possible interactions with fumarolic gases. Evidence of chemical reactions between fumarolic fluids and rain samples before and after its deposition into the sampling devices was found at Vulcano Island. Very low pH values (down to 2.5) and significant amounts of chlorine and sulfate (up to 22 mEq/l) were measured at sampling points located close to the fumarolic field. In contrast, anthropogenic contributions and/or dissolution of aerosols (both maritime and continental) influence the chemistry of rainwaters at Mt. Vesuvius, which show inter-annual variations that are highly consistent with those recorded at the coastal site at Vulcano Island. Chemistry of waters directly exposed to fumarolic fluids may then give useful information about its temporal evolution, holding the signal of the ‘‘maximum’’ chemical event occurred in the meanwhile. In addition, the observation of the health status of vegetation colonizing the immediate surroundings of the fumarolic fields, due to its strong dependence on the interactions with these fluids, may work as a possible biomarker of volcanic activity.

Description: Published

Description: 159-171

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: JCR Journal

Description: restricted

Description: We report on the paleomagnetism of ten sites in the products of the most recent silicic eruptive cycle of Pantelleria, Strait of Sicily. Previously radiometrically dated at 5–10 ka, our comparison with proxies for geomagnetic field directions allows us to narrow considerably the time window during which these eruptions occurred. The strongly peralkaline composition causes the magmas to have low viscosities, locally resulting in strong agglutination of proximal fall deposits. This allows successful extraction of paleomagnetic directions from the explosive phases of eruptions. One of our sites was located in the Serra della Fastuca fall deposit, produced by the first explosive event of the eruptive cycle. The other nine sites were located in the most recent explosive (pumice fall and agglutinate from Cuddia del Gallo and Cuddia Randazzo) and effusive (Khaggiar lava) products. The (very similar) paleomagnetic directions gathered from eight internally consistent sites were compared to reference geomagnetic field directions of the last 5–10 ka. Directions from Cuddia del Gallo agglutinate and Khaggiar flows translate into 5.9- to 6.2-ka ages, whereas the Fastuca pumices yield a slightly older age of 6.2–6.8 ka. Hence, the most recent silicic eruptive cycle lasted at most a millennium and as little as a few centuries around 6.0 ka. Paleomagnetically inferred ages are in good agreement with published (and calibrated by us) 14C dates from paleosols/charcoals sampled below the studied volcanic units, whereas K/Ar data are more scattered and yield ∼30% older ages. Our data show that the time elapsed since the most recent silicic eruptions at Pantelleria is comparable to the quiescence period separating the two latest volcanic cycles.

Description: Published

Description: 847-858

Description: 2.2. Laboratorio di paleomagnetismo

Description: JCR Journal

Description: reserved

Description: A temporary network of 33 seismic stations was deployed in the area struck by the 6th April 2009, Mw 6.3, L’Aquila earthquake (central Italy), with the aim to investigate the site amplification within the Aterno river Valley. The seismograms of 18 earthquakes recorded by 14 of the 33 stations were used to evaluate the average horizontal to vertical spectral ratio (HVSR) for each site and the standard horizontal spectral ratio (SSR) between a site and a reference station. The obtained results have been compared to the geological and geophysical information in order to explain the resonance frequencies and the amplification levels with respect to surface geology of the valley. The result indicate that there is no uniform pattern of amplification, due to the complex geologic setting, as the thickness and degree of cementation of the deposits is highly variable. As consequence, a large number of the local site response is observed, therefore it is very difficult to elaborate a unique model that can explain such a variability of the amplification.

Description: Published

Description: 697-715

Description: 4.1. Metodologie sismologiche per l'ingegneria sismica

Description: JCR Journal

Description: partially_open

Description: Changes of the susceptibility to lava flow invasion at Mount Etna are quantified by using lava flow simulations on four Digital Elevation Models documenting the morphostructural modifications of the volcano in the time interval 1986–2007. The probabilistic code DOWNFLOW is used to derive the areas invaded by several thousands of lava flows obtaining, for each DEM, maps of the susceptibility to lava flow invasion and of the lava flow hazard. These maps show, for the first time, the evolution of these surficial properties with time, and render a quantitative image of the effects of topographic changes on the preferential lava flow drainage paths. The results illustrate how the emplacement of new lava flows and the growth of scoria cones affect the probability of inundation by lava flows. We conclude that the persistent activity of this volcano requires a frequent updating of the topography for a reliable lava flow hazard assessment.

Description: Published

Description: 537-546

Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi

Description: 4.3. TTC - Scenari di pericolosità vulcanica

Description: JCR Journal

Description: reserved

Description: Strong ground-shaking mapping soon after a moderate-to-large earthquake is crucial to recognize the areas that have suffered the largest damage and losses. These maps have a fundamental role for emergency services, loss estimation and planning of emergency actions by the Civil Protection Authorities. This is particularly important for areas with high seismic risk levels, such as the Campania-Lucania Region in southern Italy. Taking advantage of the Irpinia Seismic Network (ISNet), a recently installed dense and wide dynamic seismic network, we have developed a procedure for rapid estimation of ground-shaking maps after moderate-to-large earthquakes (GRSmap). This uses an optimal data gridding scheme designed to account for bi-dimensional features of strong groundmotion fields, such as directivity, radiation patterns and focal mechanisms, to which most damage can be correlated. The basis of the mapping technique is a triangulation procedure to locally correct predicted data at the triangle barycentres where their vertices correspond to seismic stations. The method has been tested off-line using a simulated M 6.6 earthquake located at the centre of ISNet and applied to data of the 23 November 1980 Irpina M 6.9 earthquake recorded by a sparse network. This has highlighted its ability to predict peak ground-motion parameters of large magnitude earthquakes with respect to the attenuation relationships.

Description: Published

Description: 97–115

Description: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale

Description: JCR Journal

Description: reserved

Description: Experimental data and numerical modelling were used to study the effect of local geology on the seismic response of the Catania area. The town extends on a marly clays bedrock and terraced deposits made up by coastal sands and alluvial conglomerates. This sedimentary substratum is deeply entrenched by paleo-valleys filled by lava flows and pyroclastics. Available borehole data and elastic parameters were used to reconstruct a geotechnical model in order to perfome 1D numerical modeling. Seismic urban scenarios were simulated considering destructive (Mw = 7.0), strong (Mw = 6.2) and moderate (Mw = 5.7) earthquakes to assess the shaking level of the different outcropping formations. For each scenario seven real accelerograms were selected from the European Strong Motion Database to assess the expected seismic input at the bedrock. PGA and spectral acceleration at different periods were obtained in the urban area through the equivalent linear numerical code EERA, and contour maps of different levels of shaking were drawn. Standard and horizontal-to-vertical spectral ratios were achieved making use of a dataset of 172 seismic events recorded at ten sites located on the main outcropping lithotypes. Spectral ratios inferred from earthquake data were compared with theoretical transfer functions. Both experimental and numerical results confirm the role of the geological and morphologic setting of Catania. Amplification of seismic motion mainly occurs in three different stratigraphic conditions: (a) sedimentary deposits mainly diffused in the south of the study area; (b) spots of soft sediments surrounded by lava flows; (c) intensely fractured and scoriaceous basaltic lavas.

Description: In press

Description: 4.1. Metodologie sismologiche per l'ingegneria sismica

Description: JCR Journal

Description: restricted

Description: Studying the climate dynamics of past interglacials (IGs) may help to better assess the anthropogenically influenced dynamics of the current IG, the Holocene. We select IG sections from the longest ice core archive, EPICA Dome C (EDC), which covers the past 800 thousand years, and study as well several long, high-resolution marine sediment records. We analyze records of Antarctic temperature, radiative forcing (greenhouse gases and other factors), and sea-surface temperature (SST). Change-point regressions inform about longer-term climate changes and trends within IGs. Comparing trends in temperature with trends in forcing allows inference of longer-term IG climate sensitivities. Results from many records indicate deviations from a “Holocene climate optimum”. IG sensitivities are found to be comparable to estimates for the instrumental period; warming or cooling phases during Marine Isotope Stage (MIS) 5 or 11 do not show significant differences in climate sensitivity.

Description: Samples of surface snow were collected for stable isotope analysis along the traverse route from Zhongshan to Dome A (East Antarctica) from Dec 28th, 2007 to Feb. 8th, 2008. The local relationship between dD and surface temperature is established to be 6.4 ± 0.2 % per °C, very similar to the average for East Antarctic. The deuterium excess shows a pattern of high values over Antarctica, particularly at Dome A. We compare our data with an atmospheric general circulation model which includes stable water isotopes (ECHAM5-wiso). The model simulation captures the right levels of dD, but overestimates d18O. This study provides support for the ongoing deep ice core project at Dome A.

Description: We investigated the effects of warming on a natural phytoplankton community from the Baltic Sea, based on six mesocosm experiments conducted 2005–2009. We focused on differences in the dynamics of three phytoplankton size groups which are grazed to a variable extent by different zooplankton groups. While small-sized algae were mostly grazer-controlled, light and nutrient availability largely determined the growth of medium- and large-sized algae. Thus, the latter groups dominated at increased light levels. Warming increased mesozooplankton grazing on medium-sized algae, reducing their biomass. The biomass of small-sized algae was not affected by temperature, probably due to an interplay between indirect effects spreading through the food web. Thus, under the higher temperature and lower light levels anticipated for the next decades in the southern Baltic Sea, a higher share of smaller phytoplankton is expected. We conclude that considering the size structure of the phytoplankton community strongly improves the reliability of projections of climate change effects.

Description: Polygon tundra characterizes large areas of arctic lowlands. The micro-relief pattern within polygons offers differentiated habitats for testate amoeba (testacean)communities. The objective of this study was to relate testacean species distribution within a polygon to the environmental setting. Therefore, testaceans from four cryosol pits dug at different locations within a low-centered polygon were studied in the context of pedological and pedochemical data, while ground temperature and ground moisture were measured over one summer season. The study site is located on the Berelekh River floodplain (Indigirka lowland, East Siberia). The environmental data sets reflect variations along the rim-to-center transect of the polygon and in different horizons of each pit. The testacean species distribution is mainly controlled by the soil moisture regime and pH. Most of the identified testaceans are cosmopolitans; eight species are described from an arctic environment for the first time. Differences in environmental conditions are controlled by the micro-relief of polygon tundra and must be considered in arctic lowland testacean research because they bias species composition and any further (paleo-)ecological interpretation.

Description: Gene rally, the intensity and magnitude of explosive volcanic activity increase in parallel with SiO2 content. Pyro clasti cflow-forming eruptions in the Colli Albani ultrapotassic volcanic district (Italy) repres ent the most striking exception on a global scale, with volumes on the order of tens of cubic kilometres and K-foiditic compositions (SiO2 even〈42 wt.%). Here, we reconstruct the pre-eruptive scenario and event dynamics of the ~456 ka Pozzolane Rosse (PR) eruption, the largest mafic explosive event of the Colli Albani district. In particular, we focus on the driving mechanisms for the unusually explosive eruption of a low-viscosity, mafic magma. Geologic, petrographic and geochemical data with mass balance calculations, supported by experimental data for Colli Albani magma compositions, provide evidence for significant ingestion of carbonate wall rocks by the Pozzolane Rosse K-foiditic magma. Moreover, the scattered occurrence of cored bombs in Pozzolane Rosse pyroclastic-flow deposits records carbonate entrainment even at the eruptive time scale, as also tested quantitatively by thermal modelling of magma–carbonate interaction and carbonate assimilation experiments. We suggest that the addition of free CO2 from decarbonation of country rocks was the major factor controlling magma explosivity. High CO2 activity in the volatile component, coupled with magma depressurisation, produced extensive leucite crystallisation at short time scal s, resulting in a dramatic increase in magma viscosity and volatile pressurisation, which was manifested a change of eruptive dynamics from early effusion to the Pozzolane Rosse's highly explosive eruption climax.

Description: Published

Description: 241-256

Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce

Description: JCR Journal

Description: restricted

Description: © The Authors 2009. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Functional & Integrative Genomics 10 (2010): 97-110, doi:10.1007/s10142-009-0142-y.

Description: Bacteria of the genus Shewanella can thrive in different environments and demonstrate significant variability in their metabolic and ecophysiological capabilities including cold and salt tolerance. Genomic characteristics underlying this variability across species are largely unknown. In this study, we address the problem by a comparison of the physiological, metabolic, and genomic characteristics of 19 sequenced Shewanella species. We have employed two novel approaches based on association of a phenotypic trait with the number of the trait-specific protein families (Pfam domains) and on the conservation of synteny (order in the genome) of the trait-related genes. Our first approach is top-down and involves experimental evaluation and quantification of the species’ cold tolerance followed by identification of the correlated Pfam domains and genes with a conserved synteny. The second, a bottom-up approach, predicts novel phenotypes of the species by calculating profiles of each Pfam domain among their genomes and following pair-wise correlation of the profiles and their network clustering. Using the first approach, we find a link between cold and salt tolerance of the species and the presence in the genome of a Na+/H+ antiporter gene cluster. Other cold-tolerance-related genes include peptidases, chemotaxis sensory transducer proteins, a cysteine exporter, and helicases. Using the bottom-up approach, we found several novel phenotypes in the newly sequenced Shewanella species, including degradation of aromatic compounds by an aerobic hybrid pathway in Shewanella woodyi, degradation of ethanolamine by Shewanella benthica, and propanediol degradation by Shewanella putrefaciens CN32 and Shewanella sp. W3-18-1.

Description: This research was supported by the U.S. Department of Energy (DOE) Office of Biological and Environmental Research under the Genomics: GTL Program via the Shewanella Federation consortium.

Description: National seismic risk maps are an important risk mitigation tool as they can be used for the prioritization of regions within a country where retrofitting of the building stock or other risk mitigation measures should take place. The production of a seismic risk map involves the convolution of seismic hazard data, vulnerability predictions for the building stock and exposure data. The seismic risk maps produced in Italy over the past 10 years are compared in this paper with recent proposals for seismic risk maps based on state-of-the-art seismic hazard data and mechanics-based vulnerability assessment procedures. The aim of the paper is to open the discussion for the way in which future seismic risk maps could be produced, making use of the most up-to-date information in the fields of seismic hazard evaluation and vulnerability assessment.

Description: Published

Description: 149–180

Description: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale

Description: JCR Journal

Description: open

Description: The April 6, 2009 L’Aquila earthquake was responsible for an “anomalous”, relatively high degree of damage (i.e. Is 7 MCS scale) at Castelvecchio Subequo (CS). Indeed, the village is located at source-to-site distance of about 40 km, and it is surrounded by other inhabited centres to which considerably lower intensities, i.e. Is 5-6, have been attributed. Moreover, the damage was irregularly distributed within CS, being mainly concentrated in the uppermost portion of the old village. Geophysical investigations (ambient seismic noise and weak ground motions analyses) revealed that site effects occurred at CS. Amplifications of the ground motion, mainly striking NE-SW, have been detected at the uppermost portion of the carbonate ridge on which the village is built. Geological/structural and geomechanical field surveys defined that the CS ridge is affected by sets of fractures, joints and shear planes – mainly roughly NW-SE and N-S trending – that are related to the deformation zone of the Subequana valley fault system and to transfer faults linking northward the mentioned tectonic feature with the Middle Aterno Valley fault system. In particular, our investigations highlight that seismic amplifications occur where joints set NW-SE trending are open. On the other hand, no amplification is seen in portions of the ridge where the bedrock is densely fractured but no open joints occur. The fracture opening seems related to the toppling tendency of the bedrock slabs, owing to the local geomorphic setting. These investigations suggest that the detected amplification of the ground motion is probably related to the polarization of the seismic waves along the Castelvecchio Subequo ridge, with the consequent oscillation of the rock slabs perpendicularly to the fractures azimuth.

Description: Published

Description: 841-868

Description: 4.1. Metodologie sismologiche per l'ingegneria sismica

Description: JCR Journal

Description: open

Description: The 2009 Mw 6.3 L’Aquila event caused extensive damage in the city of L’Aquila and in some small towns in its vicinity. The most severe damage was recognized SE of L’Aquila town along the Aterno river valley. Although building vulnerability and near-source effects are strongly responsible for the high level of destruction, site effects have been invoked to explain the damage heterogeneities and the similarities between the 2009 macroseismic field with the intensities of historical earthquakes. The small village of Onna is settled on quaternary alluvium and suffered during the L’Aquila event an extremely heavy damage in the masonry structures with intensity IX–X on the Mercalli-Cancani-Sieberg (MCS) scale. The village of Monticchio, far less than 1.3 km from Onna, is mostly situated on Meso- zoic limestone and suffered a smaller level of damaging (VI MCS). In the present paper, we analyze the aftershock recordings at seismic stations deployed in a small area of the middle-Aterno valley including Onna and Monticchio. The aim is to investigate local ampli-fication effects caused by the near-surface geology. Because the seismological stations are close together, vulnerability and near-source effects are assumed to be constant. The wave- form analysis shows that the ground motion at Onna is systematically characterized by large high-frequency content. The frequency resonance is varying from 2 to 3 Hz and it is related to alluvial sediments with a thickness of about 40 m that overlay a stiffer Pleistocene substrate. The ground motion recordings of Onna are well reproduced by the predictive equation for the Italian territory.

Description: Published

Description: 783-807

Description: 2T. Sorgente Sismica

Description: JCR Journal

Description: reserved

Description: © The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Biogeochemistry 103 (2011): 109-124, doi:10.1007/s10533-010-9451-4.

Description: As the planet warms, widespread changes in Arctic hydrology and biogeochemistry have been documented and these changes are expected to accelerate in the future. Improved understanding of the behavior of water-borne constituents in Arctic rivers with varying hydrologic conditions, including seasonal variations in discharge–concentration relationships, will improve our ability to anticipate future changes in biogeochemical budgets due to changing hydrology. We studied the relationship between seasonal water discharge and dissolved organic carbon and nitrogen (DOC and DON) and nutrient concentrations in the upper Kuparuk River, Arctic Alaska. Fluxes of most constituents were highest during initial snowmelt runoff in spring, indicating that this historically under-studied period contributes significantly to total annual export. In particular, the initial snowmelt period (the stream is completely frozen during the winter) accounted for upwards of 35% of total export of DOC and DON estimated for the entire study period. DOC and DON concentrations were positively correlated with discharge whereas nitrate (NO3 −) and silicate were negatively correlated with discharge throughout the study. However, discharge-specific DOC and DON concentrations (i.e. concentrations compared at the same discharge level) decreased over the summer whereas discharge-specific concentrations of NO3 − and silicate increased. Soluble reactive phosphorus (SRP) and ammonium (NH4 +) were negatively correlated with discharge during the spring thaw, but were less predictable with respect to discharge thereafter. These data provide valuable information on how Arctic watershed biogeochemistry will be affected by future changes in temperature, snowfall, and rainfall in the Arctic. In particular, our results add to a growing body of research showing that nutrient export per unit of stream discharge, particularly NO3 −, is increasing in the Arctic.

Description: Funding provided by the National Science Foundation, NSF-OPP- 0436118.

Description: © The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Coral Reefs 30 (2011): 23-38, doi:10.1007/s00338-010-0705-3.

Description: Sediment traps are commonly used as standard tools for monitoring “sedimentation” in coral reef environments. In much of the literature where sediment traps were used to measure the effects of “sedimentation” on corals, it is clear from deployment descriptions and interpretations of the resulting data that information derived from sediment traps has frequently been misinterpreted or misapplied. Despite their widespread use in this setting, sediment traps do not provide quantitative information about “sedimentation” on coral surfaces. Traps can provide useful information about the relative magnitude of sediment dynamics if trap deployment standards are used. This conclusion is based first on a brief review of the state of knowledge of sediment trap dynamics, which has primarily focused on traps deployed high above the seabed in relatively deep water, followed by our understanding of near-bed sediment dynamics in shallow-water environments that characterize coral reefs. This overview is followed by the first synthesis of near-bed sediment trap data collected with concurrent hydrodynamic information in coral reef environments. This collective information is utilized to develop nine protocols for using sediment traps in coral reef environments, which focus on trap parameters that researchers can control such as trap height (H), trap mouth diameter (D), the height of the trap mouth above the substrate (z o ), and the spacing between traps. The hydrodynamic behavior of sediment traps and the limitations of data derived from these traps should be forefront when interpreting sediment trap data to infer sediment transport processes in coral reef environments.

Description: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Biology 160 (2013): 1773-1787, doi:10.1007/s00227-012-2031-5.

Description: Ocean acidification is increasingly recognized as a component of global change that could have a wide range of impacts on marine organisms, the ecosystems they live in, and the goods and services they provide humankind. Assessment of these potential socio-economic impacts requires integrated efforts between biologists, chemists, oceanographers, economists and social scientists. But because ocean acidification is a new research area, significant knowledge gaps are preventing economists from estimating its welfare impacts. For instance, economic data on the impact of ocean acidification on significant markets such as fisheries, aquaculture and tourism are very limited (if not non-existent), and non-market valuation studies on this topic are not yet available. Our paper summarizes the current understanding of future OA impacts and sets out what further information is required for economists to assess socio-economic impacts of ocean acidification. Our aim is to provide clear directions for multidisciplinary collaborative research.

Description: This paper is not subject to U.S. copyright. The definitive version was published in Environmental Biology of Fishes 97 (2014): 881-896, doi:10.1007/s10641-013-0189-4.

Description: Age and growth estimates for the dusky shark, Carcharhinus obscurus, were derived from vertebral centra collected in the northwestern Atlantic Ocean. Sample collection spanned the years prior to and following the implementation of management measures (1963–2010). Growth was compared pre- and post- population depletion and pre- and post- management to investigate the possibility of density-mediated shifts in age and growth parameters over time. There was no evidence of difference between periods for either sex. Additionally, bomb radiocarbon dating was used to determine the periodicity of band pair formation. Results support the traditional interpretation of annual band pairs up to approximately 11 years of age. After this time, vertebral counts considerably underestimate true age. Maximum validated ages were estimated to be between 38 and 42 years of age (an increase of 15 to 19 years over the band count estimates), confirming longevity to at least 42 years of age. Growth curves estimated using only validated data were compared to those generated using band pair counts. Logistic growth parameters derived from validated vertebral length-at-age data were L ∞  = 261.5 cm FL, L o  = 85.5 cm, t o  = 4.89 year and g = 0.15 year−1 for the sexes combined. Revised estimates of age at maturity were 17.4 years for males and 17.6 years for females.

Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ocean Dynamics 64 (2014): 1767-1781, doi:10.1007/s10236-014-0781-y.

Description: Locations along the inner-continental shelf offshore of Fire Island, NY, are characterized by a series of shoreface-connected ridges (SFCRs). These sand ridges have approximate dimensions of 10 km in length, 3 km spacing, and up to ∼8 m ridge to trough relief and are oriented obliquely at approximately 30° clockwise from the coastline. Stability analysis from previous studies explains how sand ridges such as these could be formed and maintained by storm-driven flows directed alongshore with a key maintenance mechanism of offshore deflected flows over ridge crests and onshore in the troughs. We examine these processes both with a limited set of idealized numerical simulations and analysis of observational data. Model results confirm that alongshore flows over the SFCRs exhibit offshore veering of currents over the ridge crests and onshore-directed flows in the troughs, and demonstrate the opposite circulation pattern for a reverse wind. To further investigate these maintenance processes, oceanographic instruments were deployed at seven sites on the SFCRs offshore of Fire Island to measure water levels, ocean currents, waves, suspended sediment concentrations, and bottom stresses from January to April 2012. Data analysis reveals that during storms with winds from the northeast, the processes of offshore deflection of currents over ridge crests and onshore in the troughs were observed, and during storm events with winds from the southwest, a reverse flow pattern over the ridges occurred. Computations of suspended sediment fluxes identify periods that are consistent with SFCR maintenance mechanisms. Alongshore winds from the northeast drove fluxes offshore on the ridge crest and onshore in the trough that would tend to promote ridge maintenance. However, alongshore winds from the southwest drove opposite circulations. The wind fields are related to different storm types that occur in the region (low-pressure systems, cold fronts, and warm fronts). From the limited data set, we identify that low-pressure systems drive sediment fluxes that tend to promote stability and maintain the SFCRs while cold front type storms appear to drive circulations that are in the opposite sense and may not be a supporting mechanism for ridge maintenance.

Description: This research was funded by the U.S. Geological Survey, Coastal and Marine Geology Program, and conducted by the Coastal Change Processes Project.

Description: This paper is not subject to U.S. copyright. The definitive version was published in Natural Hazards 74 (2014): 123-142, doi:10.1007/s11069-014-1294-1.

Description: A probabilistic technique is developed to assess the hazard from meteotsunamis. Meteotsunamis are unusual sea-level events, generated when the speed of an atmospheric pressure or wind disturbance is comparable to the phase speed of long waves in the ocean. A general aggregation equation is proposed for the probabilistic analysis, based on previous frameworks established for both tsunamis and storm surges, incorporating different sources and source parameters of meteotsunamis. Parameterization of atmospheric disturbances and numerical modeling is performed for the computation of maximum meteotsunami wave amplitudes near the coast. A historical record of pressure disturbances is used to establish a continuous analytic distribution of each parameter as well as the overall Poisson rate of occurrence. A demonstration study is presented for the northeast U.S. in which only isolated atmospheric pressure disturbances from squall lines and derechos are considered. For this study, Automated Surface Observing System stations are used to determine the historical parameters of squall lines from 2000 to 2013. The probabilistic equations are implemented using a Monte Carlo scheme, where a synthetic catalog of squall lines is compiled by sampling the parameter distributions. For each entry in the catalog, ocean wave amplitudes are computed using a numerical hydrodynamic model. Aggregation of the results from the Monte Carlo scheme results in a meteotsunami hazard curve that plots the annualized rate of exceedance with respect to maximum event amplitude for a particular location along the coast. Results from using multiple synthetic catalogs, resampled from the parent parameter distributions, yield mean and quantile hazard curves. Further refinements and improvements for probabilistic analysis of meteotsunamis are discussed.