ALBERT

Description: Gashydrate, auch „brennendes Eis“ genannt, sind faszinierende, eisähnliche Feststoffe, die aus Wasser- und Gasmolekülen aufgebaut sind und weltweit an allen aktiven und passiven Kontinentalhängen und in Permafrostgebieten vorkommen. Doch ihr unauffälliges Erscheinungsbild täuscht: Die Einschlussverbindungen können beachtliche Mengen Methangas enthalten. Daher besteht einerseits die Hoffnung auf einen möglichen neuen Energieträger und andererseits die Sorge um eine nicht zu unterschätzende Quelle an klimaschädlichem Methangas. Gashydrate, hat die neueste Forschung gezeigt, bieten zudem in vielen Bereichen industrieller Anwendung eine durchaus vielversprechende Alternative zu konventionellen Verfahren. Das vorliegende Buch gibt eine Einführung in die physikalisch-chemischen Grundlagen der Hydratbildung und die Strukturen der Gashydratphasen. Basierend auf diesem grundlegenden Verständnis erklärt es die natürlichen Gashydratvorkommen und zeichnet mögliche Methoden des Abbaus und der Gewinnung von Methangas auf. Es beleuchtet Risiken, die von den Gashydratvorkommen in der Natur ausgehen könnten, und führt in die Möglichkeiten der Nutzung dieser Einschlussverbindungen in verschiedenen industriellen Anwendungsbereichen wie z.B. der Aufbereitung von Abwässern oder der Speicherung von Gasen ein. Zielgruppe dieser kompakten Einführung in die verschiedenen Aspekte der Gashydratforschung sind Studierende der Chemie und Geowissenschaften, Ingenieure, Techniker oder auch Wissenschaftler.

Description: As the Arctic coast erodes, it drains thermokarst lakes, transforming them into lagoons and, eventually, integrates them into subsea permafrost. Lagoons represent the first stage of a thermokarst lake transition to a marine setting and possibly more saline and colder upper boundary conditions. In this research, borehole data, electrical resistivity surveying, and modelling of heat and salt diffusion were carried out at Polar Fox Lagoon on the Bykovsky Peninsula, Siberia. Polar Fox Lagoon is a seasonally isolated water body connected to Tiksi Bay through a channel, leading to hypersaline waters under the ice cover. The boreholes in the centre of the lagoon revealed floating ice and a saline cryotic bed underlain by a saline cryotic talik, a thin ice‐bearing permafrost layer, and unfrozen ground. The bathymetry showed that most of the lagoon was ice‐grounded in spring. In bedfast ice areas, the electrical resistivity profiles suggest that an unfrozen saline layer was underlain by a thick layer of refrozen talik. The modelling suggests thermokarst lake taliks refreeze when submerged in saltwater with mean annual bottom water temperatures below or slightly above 0 °C. This occurs, because the top‐down chemical degradation of newly formed ice‐bearing permafrost is slower than the cooling of the talik. Hence, lagoons may pre‐condition taliks with a layer of ice‐bearing permafrost before encroachment by the sea and this frozen layer may act as a cap on gas migration out of the underlying talik.

Description: Fram Strait in the northern North Atlantic is a key region for marine cold air outbreaks (MCAOs), southward discharges of polar air under northerly air flow, which have a strong impact on air-sea heat fluxes, boundary layer processes and severe weather. This study investigates climatologies and decadal trends of Fram Strait MCAOs of different intensity classes based on the ERA5 reanalysis product for 1979–2020. Among striking interannual variability, it is shown that the main MCAO season is December through March, when MCAOs occur around 2/3 of the time. We report on significant decadal MCAO decreases in December and January, and a significant increase in March. While the mid-winter decrease is mainly related to the different paces of warming between the surface and the lower atmosphere, the increase in March can be related to changes in synoptic circulation patterns. As an explanation for the latter, a possible feedback between retreating Barents Sea sea ice, enhanced cyclonic activity and Fram Strait MCAOs is postulated. Exemplifying the trend toward stronger MCAOs during March, the study details the recordbreaking MCAO season in early 2020, and an observational case study of an extreme MCAO event in March 2020 is conducted. Thereby, radiosonde observations are combined with kinematic air back-trajectories to provide rare observational evidence for the diabatic cooling and drying during the MCAO preconditioning phase.

Description: To provide a contribution to the Thematic Strategy for Soil Protection, here we present the results of a study focused on the potentially toxic elements (PTE) content in agricultural soils’ representative for the Mediterranean region. To reach this aim, samples of 22 Italian (NE Peloritani Mountains, Sicily) and 18 Turkish (Amik Plain, Hatay) soils were collected and analyzed to evaluate their PTE content. The Italian and Turkish sites have been selected because they represent very important cultivation zones. In Amik Plain (Turkey), the dominant crops consist of cotton, wheat, corn and olives, whereas in NE Peloritani Mountains, Sicily (Italy), an appreciate citrus variety, known as the “Interdonato lemon”, guaranteed by Protected Geographical Indication label, is produced. The collected results include: (1) the assessment of PTE levels in soils; (2) the identifcation of the PTE sources; (3) the relationships between PTE contents and soil properties (pH, electrical conductivity, organic matter, CaCO3, and clay). Several multivariate statistical methods such as correlation matrix, cluster analysis and main component analysis were applied to individuate the anthropogenic vs natural origin of the PTE sources. The detected PTE levels are in decreasing order Mn〉Zn〉V〉Cr〉Cu〉Ni〉As〉Pb〉Co〉Sb〉Se〉Cd for the Italian soils, and Mn〉 Ni〉V〉Zn〉Cr〉Cu〉Pb〉Co〉As〉Se〉Sb〉Cd for the Turkish soils. The overall obtained results allowed to defne: (a) a main lithogenic source for PTE detected in the Italian soils, except for Zn which origin is also associated to anthropogenic input; (b) a lithogenic origin for all of the PTE detected for the Turkish soils, with an associate anthropogenic contribution for Cr, Ni, V, Cu and V. The results obtained in this work enhance the knowledge in the individuation of PTE pollution sources in agricultural soils of the European Mediterranean region.

Description: Published

Description: 499

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: Fjords are recognized as hotspots of organic carbon (OC) burial in the coastal ocean. In fjords with glaciated catchments, glacier discharge carries large amounts of suspended matter. This sedimentary load includes OC from bedrock and terrigenous sources (modern vegetation, peat, soil deposits), which is either buried in the fjord or remineralized during export, acting as a potential source of CO2 to the atmosphere. In sub-Antarctic South Georgia, fjord-terminating glaciers have been retreating during the past decades, likely as a response to changing climate conditions. We determine sources of OC in surface sediments of Cumberland Bay, South Georgia, using lipid biomarkers and the bulk 14C isotopic composition, and quantify OC burial at present and for the time period of documented glacier retreat (between 1958 and 2017). Petrogenic OC is the dominant type of OC in proximity to the present-day calving fronts (60.4 ± 1.4% to 73.8 ± 2.6%) and decreases to 14.0 ± 2.7% outside the fjord, indicating that petrogenic OC is effectively buried in the fjord. Beside of marine OC, terrigenous OC comprises 2.7 ± 0.5% to 7.9 ± 5.9% and is mostly derived from modern plants and Holocene peat and soil deposits that are eroded along the flanks of the fjord, rather than released by the retreating fjord glaciers. We estimate that the retreat of tidewater glaciers between 1958 and 2017 led to an increase in petrogenic carbon accumulation of 22% in Cumberland West Bay and 6.5% in Cumberland East Bay, suggesting that successive glacier retreat does not only release petrogenic OC into the fjord, but also increases the capacity of OC burial.

Description: Coastal dynamics are the result of several processes controlling the balance between sediment input and output over time. The beach system is not always able to maintain a neutral coastal balance due to natural and anthropogenic causes. We present an integrated marine geology, geomorphological and sea-level rise analysis in the coastal sector between Torre delle Ciavole and Capo Calavà (North-Eastern Sicily, Italy).This sector is characterized by high uplift rates and frequent seismicity (mainly generated by the very active Vulcano-Tindari Fault System), promoting the development of mass-wasting processes in the coastal and offshore sectors. A main erosive feature observed in the area is the head of the Gioiosa Marea submarine canyon, located at some meters of depth, few hundred meters far the coastline. The main morphological features of the canyon were reconstructed through the analysis of high-resolution multibeam data, indicating that the canyon is active, as also testified by the comparison of time-lapse aerial photos. Due to this active setting, the study area is exposed to multiple geohazards, among which we deal with: (1) retrogressive instability at the head of the Gioiosa Marea submarine canyon, (2) coastal erosion favored by the downlope funnelling of littoral drift at the canyon head, (3) flooding scenario at 2100 using the IPCC (Intergovernmental Panel on Climate Change) and Rahmstorf sea-level projections. The consequences associated with these geohazards are amplified by the strong anthropization pressures occurring along in this sector. Our results provide key insights regarding the future scenarios of this coastal sector, revealing the effects of the retrogressive activity associated with the canyon head on the coastal strip. We also present the first management tool for the application of forecasting studies by local administrations.

Description: Published

Description: 2

Description: 3A. Geofisica marina e osservazioni multiparametriche a fondo mare

Description: JCR Journal

Description: Hillaire‐Marcelet al. bring forward several physical and geochemical arguments against our finding of an Arctic glaciolacustrine system in the past. In brief, we find that a physical approach to further test our hypothesis should additionally consider the actual bathymetry of the Greenland–Scotland Ridge (GSR), the density maximum of freshwater at 3–4°C, the sensible heat flux from rivers, and the actual volumes that are being mixed and advected. Their geochemical considerations acknowledge our original argument, but they also add a number of assumptions that are neither required to explain the observations, nor do they correspond to the lithology of the sediments. Rather than being additive in nature, their arguments of high particle flux, low particle flux, export of 230Th and accumulation of 230Th, are mutually exclusive. We first address the arguments above, before commenting on some misunderstandings of our original claim in their contribution, especially regarding our dating approach.

Description: Integrated electron microprobe analyses (EMPAs) on glass and Sr–Nd isotope analyses have been performed on 17 tephras from the Middle Pleistocene Mercure lacustrine succession, southern Apennines. Two 40Ar/39Ar ages and the recognition of four relevant tephras from Colli Albani, Sabatini and possibly Roccamonfina volcanoes allowed us to ascribe the investigated succession to the late Marine Isotope Stage (MIS) 15–12 interval (560–440 ka). The Sr–Nd isotopes and major element glass compositions allowed us to attribute 10 out of the other 13 tephras to a poorly known activity of the Roccamofina volcano, whereas two layers were tentatively attributed to previously unknown Middle Pleistocene activity of Ponza Island or Campanian volcanoes, and one to Salina Island. The tephrostratigraphic correlation of the Mercure tephras with the Acerno lacustrine pollen record (Campania) also allowed us to evaluate the climatostratigraphic position of the tephras within the framework of the MIS 15–12 climatic variability. These results were obtained by combining the Sr–Nd isotope ratio with EMPA and 40Ar/39Ar geochronological data. This confirms the notable consistency of this approach for studying the Mediterranean Middle Pleistocene tephrostratigraphy, which, despite its great potential for both volcanology and Quaternary studies, has been hitherto barely explored.

Description: Published

Description: 232–248

Description: 2V. Struttura e sistema di alimentazione dei vulcani

Description: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici

Description: 4V. Processi pre-eruttivi

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: New geochemical and isotopic data on volcanic rocks spanning the period ~75–50 ka BP on Ischia volcano, Italy, shed light on the evolution of the magmatic system before and after the catastrophic, caldera-forming Monte Epomeo Green Tuff (MEGT) eruption. Volcanic ac tivity during this period was influenced by a large, composite and differentiating magmatic system, replenished several times with isotopically distinct magmas of deepprovenance. Chemical and isotopic variations highlight that the pre-MEGT eruptions were fed by trachytic/phonolitic magmas from an isotopically zoned reservoir that were poorly enriched in radiogenic Sr and became progressively less radiogenic with time. Just prior to the MEGT eruption, the magmatic system was recharged by an isotopically distinct magma, relatively more enriched in radiogenic Sr with respect to the previously erupted magmas. This second magma initially fed several SubPlinian explosive eruptions and later supplied the climactic, phonolitic-to-trachytic MEGT eruption(s). Isotopic data, together with erupted volume estimations obtained for MEGT eruption(s), indicate that 〉5–10 km3of this relatively enriched magma had accumulated in the Ischia plumbing system. Geochemical modelling indicates that it accumulated at shallow depths (4–6 km), over a period of ca. 20 ka. After the MEGT eruption, volcanic activity was fed by a new batch of less differentiated (trachyte-latite) magma that was slightly less enriched in radiogenic Sr. The geochemical and Sr–Nd-isotopic variations through time reflect the upward flux of isotopically distinct magma batches, variably contaminated byHercynian crust at 8–12 km depth. The deep-sourced latitic to trachytic magmas stalled at shallow depths (4–6 km depth), differentiated to phonolite through crystal fractionation and assimilation of a feldspar-rich mush, or ascended directly to the surface and erupted.

Description: Published

Description: 1035

Description: 2V. Struttura e sistema di alimentazione dei vulcani

Description: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici

Description: 4V. Processi pre-eruttivi

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: During the past millennia, several eruptions have occurred within the La Fossa caldera on the island of Vulcano (Aeolian Islands, Italy), some being also described in historical documents dating back to Republican Roman times (first to second century BC). The absolute and relative timing of such activity, however, has remained poorly defined and controversial, due to contrasting ages provided by radiometric and unconventional palaeomagnetic methods. Here, we present a detailed recon- struction of the eruptive history focused on the ninth to fifteenth century AD period that occurred at both La Fossa cone and Vulcanello. This integrated approach involves tephrostratigraphy, standard palaeomagnetic methodology and radiocarbon dating. The new dataset confirms that the lavas exposed above sea level at Vulcanello were erupted between the tenth and eleventh century AD, and not between the first and second century BC as previously suggested. In this same time interval, La Fossa cone was characterized by long-lasting, shoshonitic, explosive activity followed by a discrete, sustained, rhyolitic explosive eruption. Between AD 1050 and 1300, activity was focused only on La Fossa cone, with alternating explosive and effusive eruptions that emplaced four rhyolitic and trachytic lava flows, resulting in significant growth of the cone. After the violent, phreatic event of the Breccia di Commenda (thirteenth century), the eruption continued with a substantial, long- lasting emission of fine ash until activity ceased. Magmatic explosive activity resumed at La Fossa cone at the beginning of the fifteenth century marking the onset of the Gran Cratere cycle. This phase lasted until the mid-sixteenth century and produced at least seven explosive eruptions of intermediate magma composition and a couple of lateral explosions (Forgia Vecchia I and II). During this time interval, a third cinder cone was emplaced at Vulcanello, and the activity produced the lava flows of Punta del Roveto and Valle dei Mostri. From the seventeenth to twentieth centuries, volcanic activity was concentrated at La Fossa cone, where it ended in 1890. This work confirms that Vulcanello island formed in Medieval times between the tenth and eleventh centuries. Moreover, between the tenth and mid-sixteenth centuries, La Fossa caldera was the site of at least 19 eruptions with an average eruption rate of one event every 34 years. This rate makes volcanic hazard at Vulcano higher than that suggested to date.

Description: Published

Description: 12

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: This book outlines the current development of geoethical thinking, proposing to the general public reflections and categories useful for understanding the ethical, cultural, and societal dimensions of anthropogenic global changes. Geoethics identifies and orients responsible behaviors and actions in the management of natural processes, redefining the human interaction with the Earth system based on a critical, scientifically grounded, and pragmatic approach. Solid scientific knowledge and a philosophical reference framework are crucial to face the current ecological disruption. The scientific perspective must be structured to help different human contexts while respecting social and cultural diversity. It is impossible to respond to global problems with disconnected local actions, which cannot be proposed as standard and effective operational models. Geoethics tries to overcome this fragmentation, presenting Earth sciences as the foundation of responsible human action toward the planet. Geoethics is conceived as a rational and multidisciplinary language that can bind and concretely support the international community, engaged in resolving global environmental imbalances and complex challenges, which have no national, cultural, or religious boundaries that require shared governance. Geoethics is proposed as a new reading key to rethinking the Earth as a system of complex relationships, in which the human being is an integral part of natural interactions.

Description: Published

Description: 1TM. Formazione

Description: 2TM. Divulgazione Scientifica

Description: 3TM. Comunicazione

Description: Shallow seabed depressions attributed to focused fluid seepage, known as pock- marks, have been documented in all continental margins. In this study, we dem- onstrate how pockmark formation can be the result of a combination of multiple factors— fluid type, overpressures, seafloor sediment type, stratigraphy and bot- tom currents. We integrate multibeam echosounder and seismic reflection data, sediment cores and pore water samples, with numerical models of groundwa- ter and gas hydrates, from the Canterbury Margin (off New Zealand). More than 6800 surface pockmarks, reaching densities of 100 per km2, and an undefined number of buried pockmarks, are identified in the middle to outer shelf and lower continental slope. Fluid conduits across the shelf and slope include shal- low to deep chimneys/pipes. Methane with a biogenic and/or thermogenic origin is the main fluid forming flow and escape features, although saline and fresh- ened groundwaters may also be seeping across the slope. The main drivers of fluid flow and seepage are overpressure across the slope generated by sediment loading and thin sediment overburden above the overpressured interval in the outer shelf. Other processes (e.g. methane generation and flow, a reduction in hydrostatic pressure due to sea- level lowering) may also account for fluid flow and seepage features, particularly across the shelf. Pockmark occurrence coin- cides with muddy sediments at the seafloor, whereas their planform is elongated by bottom currents.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Romagnoni, G., Kvile, K. o., Dagestad, K., Eikeset, A. M., Kristiansen, T., Stenseth, N. C., & Langangen, O. Influence of larval transport and temperature on recruitment dynamics of North Sea cod (Gadus morhua) across spatial scales of observation. Fisheries Oceanography, (2020): 1-16, doi:10.1111/fog.12474.

Description: The survival of fish eggs and larvae, and therefore recruitment success, can be critically affected by transport in ocean currents. Combining a model of early‐life stage dispersal with statistical stock–recruitment models, we investigated the role of larval transport for recruitment variability across spatial scales for the population complex of North Sea cod (Gadus morhua ). By using a coupled physical–biological model, we estimated the egg and larval transport over a 44‐year period. The oceanographic component of the model, capable of capturing the interannual variability of temperature and ocean current patterns, was coupled to the biological component, an individual‐based model (IBM) that simulated the cod eggs and larvae development and mortality. This study proposes a novel method to account for larval transport and success in stock–recruitment models: weighting the spawning stock biomass by retention rate and, in the case of multiple populations, their connectivity. Our method provides an estimate of the stock biomass contributing to recruitment and the effect of larval transport on recruitment variability. Our results indicate an effect, albeit small, in some populations at the local level. Including transport anomaly as an environmental covariate in traditional stock–recruitment models in turn captures recruitment variability at larger scales. Our study aims to quantify the role of larval transport for recruitment across spatial scales, and disentangle the roles of temperature and larval transport on effective connectivity between populations, thus informing about the potential impacts of climate change on the cod population structure in the North Sea.

Description: G.R. was supported by the Norden Top‐level Research Initiative sub‐programme “Effect Studies and Adaptation to Climate Change” through the Nordic Centre for Research on Marine Ecosystems and Resources under Climate Change (NorMER). K.Ø.K. was supported by the WHOI John H. Steele Post‐doctoral Scholar award and VISTA – a basic research program in collaboration between The Norwegian Academy of Science and Letters, and Equinor. We thank an anonymous referee for valuable comments that substantially improved the article.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Yoshii, A., & Green, W. N. Editorial: role of protein palmitoylation in synaptic plasticity and neuronal differentiation. Frontiers in Synaptic Neuroscience, 12(27), (2020), doi:10.3389/fnsyn.2020.00027.

Description: Protein palmitoylation, the reversible addition of palmitate to proteins, is a dynamic post-translational modification. Both membrane (e.g., channels, transporters, and receptors) and cytoplasmic proteins (e.g., cell adhesion, scaffolding, cytoskeletal, and signaling molecules) are substrates. In mammals, palmitoylation is mediated by 23-24 palmitoyl acyltransferases (PATs), also called ZDHHCs for their catalytic aspartate-histidine-histidine-cysteine (DHCC) domain. PATs are integral membrane proteins found in cellular membranes. In the palmitoylation cycle, palmitate is removed by the depalmitoylation enzymes, acyl palmitoyl transferases (APT1 and 2), and α/β Hydrolase domain-containing protein 17 (ABHD17A-C). These are cytoplasmic proteins that are targeted to membranes where they are substrates for PATs. The second class of depalmitoylating enzymes are palmitoyl thioesterases, PPT1 and 2, discovered through their association with infantile neuronal ceroid lipofuscinosis. These are secreted proteins found in the lumen of intracellular organelles, primarily lysosomes, where their function as depalmitoylating enzymes is unclear.

Description: This work was supported by University of Illinois start-up fund (to AY) and NIH/NIDA (grant DA044760 to WG).

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Beam, J. P., Becraft, E. D., Brown, J. M., Schulz, F., Jarett, J. K., Bezuidt, O., Poulton, N. J., Clark, K., Dunfield, P. F., Ravin, N. V., Spear, J. R., Hedlund, B. P., Kormas, K. A., Sievert, S. M., Elshahed, M. S., Barton, H. A., Stott, M. B., Eisen, J. A., Moser, D. P., Onstott, T. C., Woyke, T., & Stepanauskas, R. Ancestral absence of electron transport chains in Patescibacteria and DPANN. Frontiers in Microbiology, 11, (2020): 1848, doi:10.3389/fmicb.2020.01848.

Description: Recent discoveries suggest that the candidate superphyla Patescibacteria and DPANN constitute a large fraction of the phylogenetic diversity of Bacteria and Archaea. Their small genomes and limited coding potential have been hypothesized to be ancestral adaptations to obligate symbiotic lifestyles. To test this hypothesis, we performed cell–cell association, genomic, and phylogenetic analyses on 4,829 individual cells of Bacteria and Archaea from 46 globally distributed surface and subsurface field samples. This confirmed the ubiquity and abundance of Patescibacteria and DPANN in subsurface environments, the small size of their genomes and cells, and the divergence of their gene content from other Bacteria and Archaea. Our analyses suggest that most Patescibacteria and DPANN in the studied subsurface environments do not form specific physical associations with other microorganisms. These data also suggest that their unusual genomic features and prevalent auxotrophies may be a result of ancestral, minimal cellular energy transduction mechanisms that lack respiration, thus relying solely on fermentation for energy conservation.

Description: This work was funded by the USA National Science Foundation grants 1441717, 1826734, and 1335810 (to RS); and 1460861 (REU site at Bigelow Laboratory for Ocean Sciences). RS was also supported by the Simons Foundation grant 510023. TW, FS, and JJ were funded by the U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility supported under Contract No. DE-AC02-05CH11231. NR group was funded by the Russian Science Foundation (grant 19-14-00245). SS was funded by USA National Science Foundation grants OCE-0452333 and OCE-1136727. BH was funded by NASA Exobiology grant 80NSSC17K0548.

Description: The availability of computer tools able to describe the behavior of pyroclastic density currents (PDCs) with uncertainty quantification is of primary importance for the assessment of volcanic hazard. A common strategy to assess the intrinsic variability of these phenomena is based on the analysis of large sets of numerical simulations with variable input parameters. The use of models fast enough to allow for a large number of simulations, such as the so-called kinetic energy models, is thus advantageous. Due to the sensitivity of kinetic energy models to poorly constrained input parameters, the definition of their variation ranges is a critical step in the construction of hazard maps and a numerical calibration becomes necessary. We present a set of reproducible and structured calibration procedures of numerical models based either on a reference deposit or on the distribution of runout distance or inundation area of documented PDCs. In the first case, various metrics can be adopted to compare the model results with the reference PDC deposit (root mean square distance, Hausdorff distance, and Jaccard index), facilitating the development of scenario-based hazard assessments. Calibrations based on the distribution of runout distance or inundation area allow the construction of probabilistic hazard maps that are not conditioned on the occurrence of a specific scenario, but rather reflect the variability of the documented PDCs during the time window considered. Importantly, our calibration strategies allow one to set the input parameters considering their potential statistical dependence. These procedures have been implemented on the user-friendly versions of two kinetic energy models: ECMapProb 2.0 and BoxMapProb 2.0, whose functionalities are presented for the first time in this paper. The different calibration strategies and the functionalities of the two programs are illustrated by considering three case studies: El Misti (Peru), Merapi (Indonesia), and Campi Flegrei (Italy).

Description: Published

Description: 29

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: JCR Journal

Description: In this work, we assess ground shaking in the wider Zagreb area by computing simulated seismograms at regional distances. For the purposes of the simulations, we assemble the 3D velocity and density model and test its performance. First, we compare the low-frequency simulations obtained using deterministic method for both new 3D model and a simple 1D model. We then continue the performance test by computing the full broadband seismo- grams. To do that, we apply the hybrid technique in which the low frequency (f〈1 Hz) and high frequency (f=1–10 Hz) seismograms are obtained separately using deterministic and stochastic method, respectively, and then reconciled into a single time series. We apply this method to the MW=5.3 event and four smaller (3.0〈MW〈5.0) events that occurred in the studied region. We compare simulated data with the recorded seismograms and vali- date our results by calculating the goodness of fit score for peak ground velocity and shak- ing duration. Next, to improve the understanding of the strong ground motion in this area, we simulate seismic shaking scenarios for the 1880, MW = 6.2 earthquake. From computed low-frequency waveforms, we generate shakemaps and compare the ground-motion fea- tures of the two possible sources of this event, Kašina fault and North Medvednica fault. We conduct a preliminary study to determine which fault is a more probable source of the 1880 historic event by comparing the peak ground velocities and Arias intensity with the observed intensities.

Description: Croatian Science Foundation under the Project No. IP-2020-02-3960 European Commission, H2020 Excel- lence Science [ChEESE (Grant No. 823844)]

Description: Published

Description: 167–192

Description: 1T. Struttura della Terra

Description: 6T. Studi di pericolosità sismica e da maremoto

Description: JCR Journal

Description: Geomorphological investigations in Rome’s river valley are revealing the dynamism of the prehistoric landscape. It is becoming increasingly apparent that paleogeographic conditions that defined Rome in the historical era are the product of changes since the Bronze Age, which may be the result of local fault activity in addition to fluvial dynamism. Through a dedicated borehole chronostratigraphic study, integrated by 14C and archaeological dates, and paleomagnetic investigations, we offer here new evidence for fault displacement since ca. 4500 years/BP. We present the failure of the sedimentary fabric of a clay horizon caused by liquefaction processes commonly linked with seismic shaking, interpreting an (ca. 4 m) offset to signify the existence of a fault line located at the foot of the Capitoline Hill. In addition, we show evidence for another (ca. 1 m) offset affecting a stratigraphic horizon in the river channel, occurring along another hypothesized fault line crossing through the Tiber Valley. Movement along this fault may have contributed to a documented phase of fast overflooding dated to the sixth century BCE which eventually led to the birth of the Tiber Island. The most plausible scenario implies progressive deformation, with an average tectonic rate of 2 mm/year, along these inferred fault lines. This process was likely punctuated with moderate earthquakes, but no large event necessarily occurred. Together, the available evidence suggests that during the early centuries of sedentary habitation at the site of Rome, active fault lines contributed to significant changes to the Tiber River valley, capable of challenging lowland activities.

Description: Published

Description: 359–378

Description: 2T. Deformazione crostale attiva

Description: JCR Journal

Description: In November 2019, the fourth meeting on Volcano Observatory Best Practices workshop was held in Mexico City as a series of talks, discussions, and panels. Volcanologists from around the world offered suggestions for ways to optimize volcano-observatory crisis operations. By crisis, we mean unrest that may or may not lead to eruption, the eruption itself, or its aftermath, all of which require analysis and communications by the observatory. During a crisis, the priority of the observatory should be to acquire, process, analyze, and interpret data in a timely manner. A primary goal is to communicate effectively with the authorities in charge of civil protection. Crisis operations should rely upon exhaustive planning in the years prior to any actual unrest or eruptions. Ideally, nearly everything that observatories do during a crisis should be envisioned, prepared, and practiced prior to the actual event. Pre-existing agreements and exercises with academic and government collaborators will minimize confusion about roles and responsibilities. In the situation where planning is unfinished, observatories should prioritize close ties and communications with the land and civil-defense authorities near the most threatening volcanoes.

Description: Published

Description: 3

Description: 6SR VULCANI – Servizi e ricerca per la società

Description: N/A or not JCR

Description: The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content (OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year’s record value by 14 ± 11 ZJ (1 zetta J = 1021 J) using the IAP/CAS dataset and by 16 ± 10 ZJ using NCEI/NOAA dataset. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Niño-Southern Oscillation (ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans, and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.

Description: Published

Description: 373–385

Description: 4A. Oceanografia e clima

Description: JCR Journal

Description: Tectono-stratigraphic interpretation and sequential restoration modelling was performed over two high-resolution seismic profiles crossing the Western Ionian Basin of southern Italy. This analysis was undertaken in order to provide greater insights and a more reliable assessment of the deformation rate affecting the area. Offshore seismic profiling illuminates the sub-seafloor setting where a belt of active normal faults slice across the foot of the Malta Escarpment, a regional-scale structural boundary inherited from the Permo-Triassic palaeotectonic setting. A sequential restoration workflow was established to back-deform the entire investigated sector with the primary aim of analysing the deformation history of the three major normal faults affecting the area. Restoration of the tectono-stratigraphic model reveals how deformation rates evolved through time. In the early stage, the studied area experienced a significant deformation with the horizontal component prevailing over the vertical element. In this context, the three major faults contribute to only one third of the total deformation. The overall throw and extension then notably reduced through time towards the present day and, since the middle Pliocene, ongoing crustal deformation is accommodated almost entirely by the three major normal faults. Unloading and decompaction indicate that when compared to the unrestored seismic sections, a revision and a reduction of roughly one third of the vertical displacement of the faults offset is required. This analysis ultimately allows us to better understand the seismic potential of the region.

Description: Published

Description: 321-341

Description: 2T. Deformazione crostale attiva

Description: JCR Journal

Description: Physics of earthquake source can be investigated by monitoring active faults from borehole observatory in reservoirs (Maxwell et al. 2010) or by interpretation of seismic waves at the earth’s surface (Shearer 2019). Indeed, most information on earthquake mechanics is retrieved from seismology (e.g., Lee et al. 2002). However, the low resolution of these indirect techniques (cm to km scale) yields limited information on the physical and chemical deformation mechanisms active during earthquake rupture nucleation and propagation (Kanamori and Anderson 1975). Experimental studies of frictional instabilities on fault gouge material or pre-existing surfaces (e.g., Brace and Byerlee 1966) may overcome those limitations (Scholz 1998; Marone 1998; Persson 2013). For instance, friction controls earthquake nucleation and propagation, the static and dynamic stress drops, the frictional heat generated during slip, and consequently the energy budget of earthquakes (Scholz 2019; Di Toro et al. 2011). All these processes can be investigated and monitored through laboratory experiments. In the last decades, rock friction properties have long been investigated using triaxial apparatuses in saw-cut configuration (e.g., Jaeger 1959; Byerlee 1967; Handin 1969), in which the fault is loaded at low velocities, typically orders of µm/s, and accumulates small displacements, typically few mm. In a seminal paper, Brace and Byerlee (1966) suggested that the stick–slip phenomenon observed in these rock friction experiments is analogous to natural earthquakes. Furthermore, to address the problem of earthquakes nucleation, biaxial apparatuses were developed and have long been used to study frictional properties of experimental faults under sub-seismic slip velocities in double-direct shear configuration (e.g., Dieterich 1972; Mair et al. 2002; Collettini et al. 2014; Giorgetti et al. 2015). The biaxial apparatus developed at USGS (USA) is amongst the first biaxial apparatuses used to investigate rock frictional properties (e.g., Dieterich 1972). Other pioneering biaxial apparatuses are the one in the Rock and Sediment Mechanics Laboratory at the Pennsylvania State University (USA) (e.g., Mair et al. 2002) and BRAVA (Brittle Rock deformAtion Versatile Apparatus) installed at INGV in Rome (Italy) (Collettini et al. 2014). Although the biaxial apparatuses developed in the past 50 years are characterized by different boundary conditions in terms of forces, pressures, temperatures and size of the samples, all of them take advantages from the double-direct shear configuration that allows good control of the normal and shear forces acting of the fault, accurate measurements of fault slip and dilation/compaction, and constant contact area. Friction studies conducted with triaxial and biaxial deformation apparatuses are characterized by sub-seismic slip velocities and a limited amount of slip, 〈 10–3 m/s and few cm, respectively (e.g., Jaeger 1959; Byerlee 1967,1978; Brace and Byerlee 1966; Handin 1969; Paterson and Wong 2005; Lockner and Beeler 2002; Mair et al. 2002; Savage and Marone 2007; Samuelson et al. 2009; Carpenter et al. 2016). These experiments showed that the apparent static friction coefficient μ (i.e., μ = τ/σneff, where τ is the shear stress and σneff the effective normal stress acting on the fault) is between 0.60 and 0.85 for most rocks (Byerlee’s rule; except for phyllosilicates-rich rocks [Byerlee 1978]), for normal stresses up to 2 GPa, and temperatures up to 780 K. The apparent friction can thus be expressed as a function of slip velocity and a state variable, and modelled with the empirical rate- and state-dependent friction law (Dieterich 1979; Ruina 1983). Additionally, at velocities typical of earthquake nucleation phase, the apparent friction varies only a few percents for small changes in slip velocity, determining if a fault is or not prone to nucleate earthquakes. Although Byerlee’s rule and the rate-and-state law have many applications in earthquake mechanics (inter-seismic and nucleation phase of earthquakes), these experiments were performed at slip velocities and displacements orders of magnitude smaller than those of earthquakes. Therefore, these experiments are unable to characterize the propagation phase of earthquakes. In the last 15 years, the multiplication of the rotary shear apparatus, designed to achieve slip velocities higher than 1 m/s and infinite displacement, overcome those limitations and produced unexpected results (Di Toro et al. 2010). A pioneering rotary shear apparatus capable of achieving seismic slip velocities up to 1.3 m/s were built and installed in Japan (Shimamoto 1994). Amongst others (see Di Toro et al. 2010 and references therein), a state-of-art rotary shear apparatus (SHIVA, Slow to High-Velocity Shear Apparatus) capable of deforming samples at slip rates up to 9 m/s has been installed at INGV in Rome (Italy) (Di Toro et al. 2010). Studies performed with these rotary shear apparatuses have shown a significant decrease in fault strength with increasing slip and slip velocity. They also reveal various dynamic fault‐weakening mechanisms (frictional melting, thermal pressurization, silica gel, elastohydrodynamic lubrication) that are likely active during earthquakes, including mechanisms that were unknown before conducting these experiments. Though this new frontier is promising, key aspects of earthquake mechanics laboratory investigation, like being able to conduct high slip velocity experiments on rocks under elevated pore fluid pressure and temperatures characteristic of natural and induced earthquakes, remain beyond current experimental capabilities. Furthermore, studying links between pore‐fluid pressure, permeability, and frictional properties remains a challenge. To date, very few high-velocity friction experiments have been performed in presence of pore fluid pressure (Tanikawa 2012a, b, 2014; Violay et al. 2014, 2015, 2019; Cornelio et al. 2019a, b). In this paper, we present a new state-of-art apparatus combining the advantages of biaxial apparatuses, i.e., simple geometry, high normal forces, confining pressure and pore fluid pressure, and the advantages of the rotary shear apparatuses, i.e. high slip velocity implemented thanks to the presence of electromagnetic motors. Building on the design of recent low-velocity biaxial machines implemented with pressure vessels (Samuelson et al. 2009; Collettini et al. 2014) and implementing the system with powerful linear motors (Di Toro et al. 2010), the new HighSTEPS (High Strain TEmperature Pressure Speed) apparatus is able to reproduce the deformation conditions typical of the seismogenic crust, i.e., confining pressure up to 100 MPa, slip velocity from 10–5 to 0.25 m/s, temperature up to 120 °C, pore pressure up to 100 MPa. Under these unique boundary conditions, the new apparatus allows the investigation of the entire seismic cycle (inter-seismic, nucleation and propagation).

Description: Published

Description: 2039–2052

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: Endemic Antarctic macroalgae are especially adapted to live in extreme Antarctic conditions. Their potential biogeographic distribution niche is primarily controlled by the photoperiodic regime and seawater temperatures, since these parameters regulate growth, reproduction, and survival during the entire life cycle. Here we analyzed the upper survival temperature (UST) of juvenile sporophytes and the temperature range for sporophyte formation from gametophytes of Desmarestia menziesii, one of the dominant endemic Antarctic brown algal species. This process is a missing link to better evaluate the full biogeographical niche of this species. Two laboratory experiments were conducted. First, growth and maximum quantum yield of juvenile sporophytes were analyzed under a temperature gradient (0, 5, 10, 12, 13, 14, 15, and 16 °C) in a 16:8 h light:dark (LD) regime (Antarctic spring condition) for 2 weeks. Second, the formation of sporophytes from gametophytes (as a proxy of gametophyte reproduction) was evaluated during a 7 weeks period under a temperature gradient (0, 4, 8, 12, and 16 °C), and two different photoperiods: 6:18 h LD regime simulating winter conditions and a light regime simulating the Antarctic shift from winter to spring by gradually increasing the light period from 7.5:16.5 h LD (late winter) to 18.5:5.5 h LD (late spring). Sporophytes of D. menziesii were able to grow and survive up to 14 °C for 2 weeks without visible signs of morphological damage. Thus, this species shows the highest UST of all endemic Antarctic Desmarestiales species. In turn, gametophyte reproduction solely took place at 0 °C but not at 4–8 °C. The number of emerging sporophytes was six times higher under the light regime simulating the transition from winter to spring than under constant short day winter conditions. There was a negative relationship between the number of sporophytes formed and the gametophyte density at the beginning of the experiment, which provides evidence that gametophyte density exerts some control upon reproduction in D. menziesii. Results strongly indicate that although sporophytes and gametophytes may survive in warmer temperatures, the northernmost distribution limit of D. menziesii in South Georgia Islands is set by the low temperature requirements for gametophyte reproduction. Hence, global warming could have an impact on the distribution of this and other Antarctic species, by influencing their growth and reproduction.

Description: On 30 October 2020 a MW 7.0 earthquake occurred in the eastern Aegean Sea, between the Greek island of Samos and Turkey’s Aegean coast, causing considerable seismic damage and deaths, especially in the Turkish city of Izmir, approximately 70 km from the epicenter. In this study, we provide a detailed description of the Samos earthquake, starting from the fault rupture to the ground motion characteristics. We first use Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS) data to constrain the source mechanisms. Then, we utilize this information to analyze the ground motion characteristics of the mainshock in terms of peak ground acceleration (PGA), peak ground velocity (PGV), and spectral pseudo-accelerations. Modelling of geodetic data shows that the Samos earthquake ruptured a NNE-dipping normal fault located offshore north of Samos, with up to 2.5-3 m of slip and an estimated geodetic moment of 3.3 ⨯ 1019 Nm (MW 7.0). Although low PGA were induced by the earthquake, the ground shaking was strongly amplified in Izmir throughout the alluvial sediments. Structural damage observed in Izmir reveals the potential of seismic risk due to the local site effects. To better understand the earthquake characteristics, we generated and compared stochastic strong ground motions with the observed ground motion parameters as well as the ground motion prediction equations (GMPEs), exploring also the efficacy of the region-specific parameters which may be used to better predict the expected ground shaking from future large earthquakes in the region.

Description: Published

Description: 4745–4771

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: JCR Journal

Description: The China Seismo-Electromagnetic Satellite (CSES), China’s first satellite to measure geophysical fields with scientific goals in both space and solid earth physics, was launched successfully in February 2018. It carries high-precision magnetometers to measure the geomagnetic field. In this study, the CSES magnetic data were used to extract the signal of the lithospheric magnetic field caused by magnetized rocks in the crust and uppermost mantle. First, an along-track analysis of the CSES magnetic data was undertaken near the Bangui magnetic anomaly in central Africa and the Tarim magnetic anomaly in China, demonstrating that the CSES magnetic data are indeed sensitive to the lithospheric magnetic anomaly field. Then a lithospheric magnetic anomaly map over China and surrounding regions was derived. This map is consistent with the lithospheric part of the CHAOS-7 model. In particular, it clearly reveals four major magnetic anomalies containing long-wavelength signals at the altitude of Low-Earth-Orbiting satellites. Three magnetic highs are located over the Tarim, Sichuan and Songliao basin, the origins of which could be related to large-scale tectonic-magmatic activities during geological history. A prominent magnetic low is otherwise found in the southern Himalayan-Tibetan plateau, possibly caused by the shallow Curie depth in this region. To further improve the precision of the lithospheric magnetic field model, more detailed data processing and multi-source data merging are needed.

Description: Published

Description: 1118–1126

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: The end of the polar night with the concurrent onset of photosynthetic biomass production ultimately leads to the spring bloom, which represents the most important event of primary production for the Arctic marine ecosystem. This dataset shows, for the first time, significant in situ biomass accumulation during the dark–light transition in the high Arctic, as well as the earliest recorded positive net primary production rates together with constant chlorophyll a-normalized potential for primary production through winter and spring. The results indicate a high physiological capacity to perform photosynthesis upon re-illumination, which is in the same range as that observed during the spring bloom. Put in context with other data, the results of this study indicate that also active cells originating from the low winter standing stock in the water column, rather than solely resting stages from the sediment, can seed early spring bloom assemblages.

Description: Porous carbons are materials of wide application and their request is more and more increasing in the last years: Properly designed synthesis is presently available for the preparation of materials to be used in several fields (e.g.: adsorption, molecular separation, and catalysis). The characterization of the porous carbons is usually carried out using different techniques such as thermogravimetric analyses, Raman spectroscopy, Scanning electron microscopy, etc. In this work, the micro-Raman technique is adopted in combination with N2 physisorption at 77 K to monitor how the synthetic approach influences the presence of either amorphous or ordered regions in porous carbons. The typical D and G Raman bands of activated carbons have been carefully deconvoluted in six different components by a fitting procedure, and the determined R1 = ID1/IG ratio correlated to their specific surface area.

Description: Published

Description: 419–431

Description: 1TR. Georisorse

Description: JCR Journal

Description: The aim of this study is to improve our knowledge of the attenuation structure in the Southern Apennines using a new amplitude ratio tomography method (Phillips et al., Geophys Res Lett 32(21): L21301, 2005) applied on both direct and coda envelope measurements derived from 150 events recorded by 47 stations of the Istituto Nazionale di Geofisica e Vulcanologia National Seismic Network (Rete Sismica Nazionale Centralizzata). The twodimensional (2-D) analysis allows us to take into account lateral crustal variations and heterogeneities of this region. Using the same event and station distribution, we also applied a simple 1-D methodology, and the performance of the 1-D and 2-D path assumptions is tested by comparing the average interstation variance for the path-corrected amplitudes using coda and direct waves. In general, coda measurement results are more stable than using direct waves when the same methodology is applied. Using the 2-D approach, we observe more stable results for both waves. However, the improvement is quite small, probably because the crustal heterogeneity is weak. This means that, for this region, the 1-D path assumption is a good approximation of the attenuation characteristics of the region. A comparison between Q tomography images obtained using direct and coda amplitudes shows similar results, consistent with the geology of the region. In fact, we observe low Q along the Apennine chain toward the Tyrrhenian Sea and higher values to the east, in correspondence with the Gargano zone that is related to the Apulia Carbonate Platform. Finally, we compared our results with the coda Q values proposed by Bianco et al. (Geophys J Int 150:10–22, 2002) for the same region. The good agreement validates our results as the authors used a completely independent methodology.

Description: Published

Description: 355–365

Description: 1T. Struttura della Terra

Description: JCR Journal

Description: The petrological study of volcanic products emitted during the paroxysmal events of December 2015 from the summit craters of Mount Etna allow us to constrain T-P-XH2O phase stability, crystallization conditions, and mixing processes along the main open-conduit feeding system. In this study, we discuss new geochemical, thermo-barometric data and related Rhyolite- MELTS modelling of the eruptive activity that involved the concomitant activation of all summit craters. The results, in comparison with the previous paroxysmal events of the 2011–2012, reinforce the model of a vertically extended feeding system and highlight that the activity at the New South-East Crater was fed by magma residing at a significantly shallower depth with respect to the Central Craters (CC) and North-East Crater (NEC), even if all conduits were fed by a common deep (P = 530–440 MPa) basic magmatic input. Plagioclase dissolution, resorption textures, and the Rhyolite-MELTS stability model corroborate its dependence on H2O content; thus, suggesting that further studies on the effect that flushing from fluids with different H2O/ CO2 ratio are needed to understand the eruption-triggering mechanisms for high energetic strombolian paroxysmal episodes.

Description: Published

Description: 88

Description: 2V. Struttura e sistema di alimentazione dei vulcani

Description: 4V. Processi pre-eruttivi

Description: JCR Journal

Description: Validation and benchmarking of pyroclastic current (PC) models is required to evaluate their performance and their reliability for hazard assessment. Here, we present results of a benchmarking initiative built to evaluate four models commonly used to assess concentrated PC hazard: SHALTOP, TITAN2D, VolcFlow, and IMEX_SfloW2D. The benchmark focuses on the simulation of channelized flows with similar source conditions over five different synthetic channel geometries: (1) a flat incline plane, (2) a channel with a sharp 45° bend, (3) a straight channel with a break-in-slope, (4) a straight channel with an obstacle, and (5) a straight channel with a constriction. Several outputs from 60 simulations using three different initial volume fluxes were investigated to evaluate the performance of the four models when simulating valley-confined PC kinematics, including overflows induced by topographic changes. Quantification of the differences obtained between model outputs at t = 100 s allowed us to identify (1) issues with the Voellmy-Salm implementation of TITAN2D and (2) small discrepancies between the three other codes that are either due to various curvature and velocity formulations and/or numerical frameworks. Benchmark results were also in agreement with field observations of natural PCs: a sudden change in channel geometries combined with a high-volume flux is key to generate overflows. The synthetic benchmarks proved to be useful for evaluating model performance, needed for PC hazard assessment. The overarching goal is to provide an interpretation framework for volcanic mass flow hazard assessment studies to the geoscience community.

Description: Published

Description: 75

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal

Description: Free access at https://onlinelibrary.wiley.com/doi/10.1111/1755-6724.14824

Description: Earthquake is a sudden release of energy due to fault motions. The severity of the damages can be minimized by development of a culture of prevention which includes the Seismic Hazard Assessment, microzonation studies and appropriate building codes. Earthquake risk assessment methods require seismo tectonic information usually organized in earthquake catalogues utilized in Probabilistic Seismic Hazard Assessment (PSHA) based on initial work by Cornell (1968), where probability distributions for magnitudes and source site distances reported in earthquake catalogues were utilized for the first time. In following years the method furtherly improved reporting an upper bound on the earthquake magnitude in each region avoiding the inclusion of unrealistically big earthquakes. A different approach has been followed in Countries characterized by significant incompletenesses in available earthquake catalogues. In these places the Deterministic Seismic Hazard Assessment (DSHA) methods have been often utilized. In particular the DSHA takes into account the maximum possible earthquake to evaluate the intensity of seismic ground motion distribution at a site by taking account the seismotectonic setup of the area. A deepening in the knowledge of seismotectonics and of morphostructural features of the studied area has been carried out in pattern recognition studies (Gelfand et al., 1976 and references therein). More updated applications named Neo-Deterministic Seismic Hazard Assessment (NDSHA) proposed by Wang et al. (2021) also consider morphostructural zoning which, in turn, considers nodes (fractured areas), lineaments and topographical features like the maximal elevation and the minimal elevation of the studied area. The steepness of topographic surfaces and sharp variations in morphostructural parameters indicate high tectonic activity. Some geological features are also presently utilized in PSHA methods in some Countries and considers basic parameters like the top and the bottom of seismogenic layers deduced by faults geometry within the frame of the Earthquake Rupture Forecasting (Bird and Liu, 2007).

Description: Published

Description: 31-33

Description: 9T. Geochimica dei fluidi applicata allo studio e al monitoraggio di aree sismiche

Description: JCR Journal

Description: Relative sea‐level (RSL) evolution during Marine Isotopic Stage (MIS) 5 in the Mediterranean basin is still not fully understood despite a plethora of morphological, stratigraphic and geochronological studies carried out on highstand deposits of this area. In this review we assembled a database of 323 U/Th‐dated samples (e.g. corals, molluscs, speleothems) which were used to chronologically constrain RSL evolution within MIS 5. The application of strict geochemical criteria to the U/Th samples indicates that only ~33% of data available for the Mediterranean Sea can be considered ‘reliable’. Most of these data (~65%) refer to the MIS 5e highstand, while only ~17% could be related to the MIS 5a. No attribution to MIS 5c can be unequivocally supported. Nevertheless, the resulting framework does not allow us to define a satisfactory RSL trend during the MIS 5e highstand and subsequent MIS 5 substages. Overall, the proposed selection of reliable/unreliable data would be useful for detecting areas where MIS 5 substage attributions are not supported by confident U/Th chronological data and thus the related reconstructions need to be revised. In this regard, the resulting framework calls for a reappraisal and re‐examination of the Mediterranean records with advanced geochronological methodologies.

Description: Published

Description: 1174-1189

Description: 5A. Ricerche polari e paleoclima

Description: JCR Journal

Description: Deciphering magma evolution below ocean basaltic volcanoes is all the more challenging because magma mixing is a common process tending to modify the pristine geochemical diversity during magma ascent. On the western flank of the Piton de la Fournaise volcano, transitional basalts have compositions that testify to origins down to the upper mantle and display a widespread geochemical diversity ranging from a tholeiitic affinity to an alkaline one. There, we show that evolved melt inclusions and matrix glasses (MgO 〈 9 wt%) record an alkali enrichment coupled with a Ca/Al ratio decrease, which tracks the effect of clinopyroxene crystallization at the depth of the mantle-crust underplating layer. At this depth and shallower, reverse zoning of olivine crystals, clinopyroxene dissolution, and hybrid melt compositions testify to extensive mixing processes leading to a homogenization of the pristine geochemical footprint of melts upon ascent. Enrichment in incompatible trace elements in some evolved melt inclusions suggests that magma ponding at the depth of the mantle-crust underplating layer favours also assimilation of melts originating from low degrees of partial melting of cumulates (wehrlites, dunites). Conversely, the most primitive melt inclusions documented so far at La Réunion Island (MgO up to 11.2 wt%) better preserve a pristine geochemical variability related to partial melting of a slightly heterogeneous mantle source. We suggest that these slightly distinct source components may mirror the compositions of recent melts from the two closely located Piton de la Fournaise and Piton des Neiges volcanoes.

Description: Published

Description: 84

Description: 2V. Struttura e sistema di alimentazione dei vulcani

Description: 4V. Processi pre-eruttivi

Description: JCR Journal

Description: We used 1029 earthquakes, with magnitudes ranging from M 3.0 to M 6.5, located in central Apennines, Italy, and recorded by 414 local stations to study the variation of the quality factor QS of shear waves with depth. We first determined average nonparametric attenuation functions in the frequency band from 0.5 to 20 Hz and hypocenter distances less than 155 km to correct the observed acceleration spectra for attenuation effects. Then, we separated source and site effects from the corrected spectral records to determine the changes of QS with depth. We used a 1D local shear-wave velocity model to calculate the travel times of the source-station paths, and we inverted the observed spectra to determine QS in three different depth intervals (0–4 km, 4–10 km and 10–15 km) and five frequencies (0.5, 1, 4, 10 and 20 Hz). We found that QS increases with frequency at all depths considered and tends to have lower values at shallow depths. The average value of QS is consistent with previous studies made in central Italy and can be approximated by QS = 43f0.94. To describe the frequency dependence of QS with depth (H), we determine the following relations: QS = 5.5f1.39, 0.5 ≤ f ≤ 10 Hz and QS = 151.5, f 〉 10 Hz for 0–4 km, QS = 52f0.87 for 4 〈 H 〈 10 km and QS = 51f0.92 for 10 ≤ H ≤ 15 km. We conclude that the Q-depth-dependent model can be useful to improve estimates of source parameters and ground motion prediction in the central Apennines region of Italy.

Description: Published

Description: 2059–2075

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: JCR Journal

Description: Correction to: Natural Hazards https://doi.org/10.1007/s11069-021-04675-z

Description: Correction to: Natural Hazards https://doi.org/10.1007/s11069-021-04675-z

Description: Published

Description: 203

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: Physics-based broadband ground-motion simulations are generated for the strong mainshocks that occurred in the region of the Central Ionian Islands, on 26th January 2014 in Kefalonia (Mw6.1) and 17th November 2015 in Lefkas (Mw6.5). The study area is associated with frequent strong earthquakes both in the historical and instrumental eras. During the last decades, the network of strong-motion accelerographs in the area has been densified, and thus provided an adequate number of strong ground-motion records as a means to better examine the related ground-motion characteristics. In the present study, broadband ground motions for the two case studies are simulated both at selected sites and at a dense grid of points covering the affected areas. The low-frequency part of the synthetics is computed using a discrete wavenumber finite element method by convolving Green’s functions with a kinematic slip model in the frequency domain. A stochastic finite fault model approach based on a dynamic corner frequency is considered to calculate the ground motions for the higher frequencies. The broadband synthetic time series are generated after merging the results obtained from the two separate techniques, by performing a weighted summation at intermediate frequencies. The simulated values are validated by comparison with both recorded Peak Ground Acceleration (PGA) and PeakGround Velocity (PGV) values and the estimated ones by using widely accepted Ground Motion Prediction Equations (GMPEs). Our results indicate that both the spatial distribution and the amplification pattern of the simulated ground motions, in the near-field, in terms of PGA and PGV are highly influenced by the slip heterogeneity and the maximum slip patches within the seismic source.

Description: Published

Description: 3505–3527

Description: 6T. Studi di pericolosità sismica e da maremoto

Description: JCR Journal

Description: Stromboli is an active, open conduit mafic volcano, whose persistent mild Strombolian activity is occasionally punctuated by much stronger explosions, known as paroxysms. During summer 2019, the volcano unexpectedly produced one such paroxysm on July 3, followed by intense explosive and intermittent effusive activity culminating in a second paroxysm on August 28. Visual observations and the analysis of the fall deposits associated with the two paroxysms allowed us to reconstruct ballistic exit velocities of up to 160 m s−1. Plume heights of ~ 8.4 km and 6.4 km estimated for the two events correspond to mass eruption rates of 1.1 x 10 6 kg s−1 and 3.6 x 105 kg s−1, respectively. This is certainly an underestimate as directional pyroclastic flows into which mass was partitioned immediately formed, triggering small tsunamis at the sea entrance. The mass of ballistic spatters and blocks erupted during the July 3 event formed a continuous cover at the summit of the volcano, with a mass calculated at ~ 1.4 x 10 8 kg. The distribution of fall deposits of both the July 3 and August 28 events suggests that pyroclasts characterized by terminal fall velocities 〈 10–20 m s−1 remained fully suspended within the convective region of the plume and did not fall at distances closer than ca 1700 m to the vent. Based on the impulsive, blast-like phenomenology of paroxysms as well as the deposit distribution and type, paroxysms are classified as basaltic Vulcanian in style. The evolution of the summer 2019 eruptive events was not properly captured within the framework of the alert level system which is focused on tsunamigenic processes, and this is discussed so as to provide elements for the implementation of the reference scenarios and an upgrade of the system to take into account such events. In particular we find that, although still largely unpredictable, at least at operational time scales, and not necessarily tsunamigenic, Vulcanian eruptions and the subsequent evolution of the eruptive phenomena should be considered for the alert level system. This serves as a warning to the implementation of alert systems where the unexpected needs to be taken into account, even at systems that are believed to be relatively “predictable” as is the case at many persistently active, open vent mafic systems.

Description: Published

Description: 1

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal

Description: This paper reports on experiments devoted to explore the role of specific attributes of humanoid virtual agents that may influence elderly users’ perception and attitude, determining their acceptance and adoption as assistive devices. In particular, it investigates elderly preference on agents’ gender and the role of the agents’ ability to use voice during the interaction. To this aim two different groups of seniors were involved in the experiments. The first group evaluated talking virtual agents, the second one the same virtual agents, but silenced. The data shows that elderly users, independently from their gender, prefer to interact with female agents, especially when they are able to talk to them, revealing the role played by the voice. Furthermore, it was found a significant effect of the elderly level of experience with technology: when interacting with agents with voice, elderly users with high technological experience were less interested and considered the proposed agents less attractive and appealing, while just the opposite occurred when interacting with silenced agents.

Description: Published

Description: 4429–4436

Description: 5TM. Informazione ed editoria

Description: JCR Journal

Description: The Apennines are a retreating collisional belt where the foreland basin system, across large domains, is floored by a subaerial forebulge unconformity developed due to forebulge uplift and erosion. This unconformity is overlain by a diachronous sequence of three lithostratigraphic units made of (a) shallow-water carbonates, (b) hemipelagic marls and shales and (c) siliciclastic turbidites. Typically, the latter two have been interpreted regionally as the onset of syn-orogenic deposition in the foredeep depozone, whereas little attention has been given to the underlying unit. Accordingly, the rate of migration of the central-southern Apennine fold-thrust beltforeland basin system has been constrained, so far, exclusively considering the age of the hemipelagites and turbidites, which largely post-date the onset of foredeep depozone. In this work, we provide new high-resolution ages obtained by strontium isotope stratigraphy applied to calcitic bivalve shells sampled at the base of the first syn-orogenic deposits overlying the Eocene-Cretaceous pre-orogenic substratum. Integration of our results with published data indicates progressive rejuvenation of the strata sealing the forebulge unconformity towards the outer portions of the foldthrust belt. In particular, the age of the forebulge unconformity linearly scales with the pre-orogenic position of the analysed sites, pointing to an overall constant migration velocity of the forebulge wave in the last 25 Myr.

Description: Published

Description: 2817-2836

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: We present a novel method to estimate dynamic ice loss of Greenland's three largest outlet glaciers: Jakobshavn Isbræ, Kangerlussuaq Glacier, and Helheim Glacier. We use Global Navigation Satellite System (GNSS) stations attached to bedrock to measure elastic displacements of the solid Earth caused by dynamic thinning near the glacier terminus. When we compare our results with discharge, we find a time lag between glacier speedup/slowdown and onset of dynamic thinning/thickening. Our results show that dynamic thinning/thickening on Jakobshavn Isbræ occurs 0.87 ± 0.07 years before speedup/slowdown. This implies that using GNSS time series we are able to predict speedup/slowdown of Jakobshavn Isbræ by up to 10.4 months. For Kangerlussuaq Glacier the lag between thinning/thickening and speedup/slowdown is 0.37 ± 0.17 years (4.4 months). Our methodology and results could be important for studies that attempt to model and understand mechanisms controlling short-term dynamic fluctuations of outlet glaciers in Greenland.

Description: This work presents a novel empirical Ground Motion prediction Model (GMM) for vertical-to-horizontal (VH) response spectral amplitudes up to 10 s, peak ground acceleration and velocity for shallow crustal earthquakes in Italy. Being calibrated on the most up-to-date strong motion dataset for Italian crustal earthquakes (ITA18), the model is consistent with the ITA18 GMM for the horizontal ground motion. This property makes the model useful in probabilistic seismic hazard assessment for Italy to derive compatible vertical and horizontal response spectra. To account for the increase of VH ratios in the proximity of the seismic source, an adjustment term is introduced to improve the prediction capability of the model in near-source conditions, relying on the worldwide NEar-Source Strong motion dataset (NESS). The proposed model uses a simple functional form restricted to a limited number of predictor variables, namely, magnitude, source-to-site distance, focal mechanism, and site effects, and the variability associated with both VH and V models is provided.

Description: Published

Description: 4121-4141

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: JCR Journal

Description: Risk assessments in volcanic contexts are complicated by the multi-hazard nature of both unrest and eruption phases, which frequently occur over a wide range of spatial and temporal scales. As an attempt to capture the multi-dimensional and dynamic nature of volcanic risk, we developed an integrAteD VolcanIc risk asSEssment (ADVISE) model that focuses on two temporal dimensions that authorities have to address in a volcanic context: short-term emergency management and long-term risk management. The output of risk assessment in the ADVISE model is expressed in terms of potential physical, functional, and systemic damage, determined by combining the available information on hazard, exposed systems and vulnerability. The ADVISE model permits qualitative, semi-quantitative and quantitative risk assessment depending on the final objective and on the available information. The proposed approach has evolved over a decade of study on the volcanic island of Vulcano (Italy), where recent signs of unrest combined with uncontrolled urban development and significant seasonal variations of exposed population result in highly dynamic volcanic risk. For the sake of illustration of all the steps of the ADVISE model, we focus here on the risk assessment of the transport system in relation to the tephra fallout associated with a long-lasting Vulcanian cycle.

Description: Published

Description: 7

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: N/A or not JCR

Description: The Campi Flegrei volcano (or Phlegraean Fields), Campania, Italy, generated the largest eruption in Europe in at least 200 ka. Here we summarise the volcanic and human history of Campi Flegrei and discuss the interactions between humans and the environment within the “burning felds” from around 10,000 years until the 1538 CE Monte Nuovo eruption and more recent times. The region’s incredibly rich written history documents how the landscape changed both naturally and anthropogenically, with the volcanic system fuelling these considerable natural changes. Humans have exploited the beautiful landscape, accessible resources (e.g. volcanic ash for pulvis puteolana mortar) and natural thermal springs associated with the volcano for millennia, but they have also endured the downsides of living in a volcanically active region—earthquakes, signifcant ground deformation and landscape altering eruptions. The pre-historic record is detailed, and various archaeological sites indicate that the region was certainly occupied in the last 10,000 years. This history has been reconstructed by identifying archaeological fnds in sequences that often contain ash (tephra) layers from some of the numerous volcanic eruptions from Campi Flegrei and the other volcanoes in the region that were active at the time (Vesuvius and Ischia). These tephra layers provide both a relative and absolute chronology and allow the archaeology to be placed on a relatively precise timescale. The records testify that people have inhabited the area even when Campi Flegrei was particularly active.The archaeological sequences and outcrops of pyroclastic material preserve details about the eruption dynamics, buildings from Roman times, impressive craters that now host volcanic lakes and nature reserves, all of which make this region particularly mystic and fascinating, especially when we observe how society continues to live within the active caldera system. The volcanic activity and long record of occupation and use of volcanic resources in the region make it unique and here we outline key aspects of its geoheritage.

Description: Published

Description: 5

Description: 1V. Storia eruttiva

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: 6SR VULCANI – Servizi e ricerca per la società

Description: JCR Journal

Description: Here, we report on the Quaternary Volsci Volcanic Field (VVF, central Italy). In light of new 40Ar/39Ar geochronological data and compositional characterization of juvenile eruptive products, we refine the history of VVF activity, and outline the implications on the pre-eruptive magma system and the continental subduction processes involved. Different from the nearby volcanic districts of the Roman and Campanian Provinces, the VVF was characterized by small-volume (0.01–0.1 km3) eruptions from a network of monogenetic centers (mostly tuff rings and scoria cones, with subordinate lava occurrences), clustered along high-angle faults of lithospheric depth. Leucite-bearing, high-K (HKS) magmas (for which we report for the first time the phlogopite phenocryst compositions) mostly fed the early phase of activity (∼761–539 ka), then primitive, plagioclase-bearing (KS) magmas appeared during the climactic phase (∼424–349 ka), partially overlapping with HKS ones, and then prevailed during the late phase of activity (∼300–231 ka). The fast ascent of primitive magma batches is typical of a tectonically controlled volcanic field, where the very low magma flux is a passive byproduct of regional tectonic strain. We suggest that the dominant compressive stress field acting at depth was accompanied by an extensional regime in the upper crust, associated with the gravity spreading of the Apennine chain, allowing the fast ascent of magma from the mantle source with limited stationing in shallow reservoirs.

Description: Published

Description: 689–718

Description: 1V. Storia eruttiva

Description: JCR Journal

Description: Numerical results of a two-layer depth-averaged model of pyroclastic density currents (PDCs) were compared with an experimental PDC generated at the international eruption simulator facility (the Pyroclastic flow Eruption Large-scale Experiment (PELE)) to establish a minimal dynamical model of PDCs with stratification of particle concentrations. In the present two-layer model, the stratification in PDCs is modeled as a voluminous suspended-load layer with low particle volume fractions ( ≲ 10−3) and a thin basal bed-load layer with higher particle volume fractions ( ∼ 10−2 ) on the basis of the source condition in the experiment. Numerical results for the suspended load quantitatively reproduce the time evolutions of the front position and flow thickness in the experimental PDC. The numerical results of the bed-load and deposit thicknesses depend on an assumed value of settling speed at the bottom of the bed load ( WsH ). We show that the thicknesses of bed load and deposit in the simulations agree well with the experimental data, when WsH is set to about 1.25 × 10−2 m/s. This value of the settling speed is two orders of magnitude smaller than that predicted by a hindered-settling model. The small value of WsH is considered to result from decreasing in the effective deposition speed due to the erosion process accompanied by saltating/rolling of particles at the bottom of the bed load.

Description: Published

Description: 73

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal

Description: A new analysis of high-resolution multibeam and seismic reflection data, collected during several oceanographic expeditions starting from 1999, allowed us to compile an updated morphotectonic map of the North Anatolian Fault below the Sea of Marmara. We reconstructed kinematics and geometries of individual fault segments, active at the time scale of 10 ka, an interval which includes several earthquake cycles, taking as stratigraphic marker the base of the latest marine transgression. Given the high deformation rates relative to sediment supply, most active tectonic structures have a morphological expression at the seafloor, even in presence of composite fault geometries and/or overprinting due to mass-wasting or turbidite deposits. In the frame of the right-lateral strike-slip domain characterizing the North Anatolian fault system, three types of deformation are observed: almost pure strike-slip faults, oriented mainly E–W; NE/SW-aligned axes of transpressive structures; NW/SE-oriented trans-tensional depressions. Fault segmentation occurs at different scales, but main segments develop alongthree major right-lateral oversteps, which delimit main fault branches, from east to west: (i) the transtensive Cinarcik segment; (ii) the Central (East and West) segments; and (iii) the westernmost Tekirdag segment. A quantitative morphometric analysis of the shallow deformation patterns observed by seafloor morphology maps and high-resolution seismic reflection profiles along the entire basin allowed to determine nature and cumulative lengths of individual fault segments. These data were used as inputs for empirical relationships, to estimate maximum expected Moment Magnitudes, obtaining values in the range of 6.8–7.4 for the Central, and 6.9–7.1 for the Cinarcik and Tekirdag segments, respectively. We discuss these findings considering analyses of historical catalogues and available paleoseismological studies for the Sea of Marmara regionto formulate reliable seismic hazard scenarios.

Description: Published

Description: 29–44

Description: 6T. Studi di pericolosità sismica e da maremoto

Description: N/A or not JCR

Description: Diffusive gradients in thin fi lms (DGT) have been tested in CO2-rich, metal-bearing fl uids from springs in the Campo de Calatrava region in Central Spain, to assess their applicability as a monitoring tool in onshore CO2 storage projects. These fi lms are capable of adsorbing metals and recording changes in their concentration in water, sediments, and soils. Considering that CO2 dissolution promotes metal solubilization and transport, the use of these fi lms could be valuable as a monitoring tool of early leakage. A number of DGT have been deployed in selected springs with constant metal concentration. The studied waters show high concentrations of Fe, as high as 1 × 104 μg·L–1, Ni, Co, Zn, Cu, and Mn. Comparing re-calculated metal concentration in DGT with metal water concentration, two different metal behaviors are observed: (i) metals with sorption consistent with the metal concentration (i.e. plotting close to the 1:1 line in a [Me]DGT: [Me]water plot), and (ii) metals with non–linear sorption, with some data showing metal enrichment in DGT compared with the concentration in water. Metals in the fi rst group include Fe, Mn, Co, Ni, and U, and metals in the second group are Zn, Pb, Cr, Cu, and Al. From this research, it is concluded that the metals in the fi rst group can be used to monitor potential leakage by using DGT, providing effective leakage detection even considering low variations of concentrations, episodic metal release, and reducing costs compared with conventional, periodic water sampling.

Description: Published

Description: 163-175

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: Future occurrence of explosive eruptive activity at Cotopaxi and Guagua Pichincha volcanoes, Ecuador, is assessed probabilistically, utilizing expert elicitation. Eight eruption types were considered for each volcano. Type event probabilities were evaluated for the next eruption at each volcano and for at least one of each type within the next 100 years. For each type, we elicited relevant eruption source parameters (duration, average plume height, and total tephra mass). We investigated the robustness of these elicited evaluations by deriving probability uncertainties using three expert scoring methods. For Cotopaxi, we considered both rhyolitic and andesitic magmas. Elicitation findings indicate that the most probable next eruption type is an andesitic hydrovolcanic/ash-emission (~ 26–44% median probability), which has also the highest median probability of recurring over the next 100 years. However, for the next eruption at Cotopaxi, the average joint probabilities for sub-Plinian or Plinian type eruption is of order 30–40%—a significant chance of a violent explosive event. It is inferred that any Cotopaxi rhyolitic eruption could involve a longer duration and greater erupted mass than an andesitic event, likely producing a prolonged emergency. For Guagua Pichincha, future eruption types are expected to be andesitic/dacitic, and a vulcanian event is judged most probable for the next eruption (median probability ~40–55%); this type is expected to be most frequent over the next 100 years, too. However, there is a substantial probability (possibly 〉40% in average) that the next eruption could be sub-Plinian or Plinian, with all that implies for hazard levels.

Description: Published

Description: 35

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: JCR Journal

Description: We present a new geometrical method capable of quantifying and illustrating the outcomes of a three-component mixing dynamics. In a three-component mixing sce nario, classical algebraic equations and endmember mixing analysis (EMMA) can be used to quantify the contributions from each fraction. Three-component mixing of natural waters, either in an element–element plot or by using the EMMA mixing sub space is described by a triangular shaped distribution of sample points where each endmember is placed on an apex, while each side corresponds to the mixing function of the two endmembers placed at the apex, considering the third endmembers' con tribution equal to zero. Along each side, the theoretical mixing fractions can be com puted using mass balance equations. Samples with contributions from three endmembers will plot inside the triangle, while the homogeneous barycentric coordi nate projections can be projected onto the three sides. The geochemistry observed in the mineralized Ferrarelle aquifer system (southern Italy) results from three component mixing of groundwater, each with diagnostic geochemical compositions. The defined boundary conditions allow us to parameterize and validate the proce dures for modelling mixing, including selection of suitable geochemical tracer

Description: Published

Description: e14409

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: Exposure to volcanic ash is a long-standing health concern for people living near active volcanoes and in distal urban areas. During transport and deposition, ash is subjected to various physicochemical processes that may change its surface composition and, consequently, bioreactivity. One such process is the interaction with anthropogenic pollutants; however, the potential for adsorbed, deleterious organic compounds to directly impact human health is unknown. We use an in vitro bioanalytical approach to screen for the presence of organic compounds of toxicological concern on ash surfaces and assess their biological potency. These compounds include polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzop- dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dlPCBs). Analysis of ash collected in or near urbanised areas at five active volcanoes across the world (Etna, Italy; Fuego, Guatemala; Kelud, Indonesia; Sakurajima, Japan; Tungurahua, Ecuador) using the bioassay inferred the presence of such compounds on all samples. A relatively low response to PCDD/Fs and the absence of a dlPCBs response in the bioassay suggest that the measured activity is dominated by PAHs and PAH-like compounds. This study is the first to demonstrate a biological potency of organic pollutants associated with volcanic ash particles. According to our estimations, they are present in quantities below recommended exposure limits and likely pose a low direct concern for human health.

Description: Published

Description: 30

Description: 7SR AMBIENTE – Servizi e ricerca per la società

Description: JCR Journal

Description: Correction to: Bulletin of Earthquake Engineering https://doi.org/10.1007/s10518-021-01077-1

Description: Published

Description: 3317

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: JCR Journal

Description: Poás is a complex stratovolcano with an altitude of 2,708 m asl, located in the Cordillera Volcánica Central of Costa Rica. Prior to 2017, the last three historical eruptions occurred on 7 February 1834, between January and May 1910 and during the period 1953-1955. Very few literature exists on the 1834 eruption. The only references state that it was an important event, that ash reached 〉53 km W-SW of Poás, and that it harmed the grasslands around the volcano. Related deposits of this eruption suggest phreatic activity, which launched bombs and blocks. Moreover, there is evidence of pyroclastic flow deposits near the crater. The 1910 eruption is better described. Despite the fact that ash fall is only reported near the volcano, a volume of the deposit of 1.6 x 107 m3 is estimated. Deposits of the eruption are white in color with many hydrothermally altered, and minor presence of juvenile fragments (vesicular lapilli). The eruption is classified as vulcanian, with deposits of ash fall and pyroclastic flows close to the crater. A Volcano Explosivity Index 3 (VEI 3) is estimated. The eruption affected agriculture. The 1953-1955 eruptions had a longer duration. Various ash fall deposits at several sites are reported. Deposits of this eruption, easily distinguished in the field, are black scoria lapilli, bombs with, sometimes fusiform, bread crust textures. In the eastern sector of the crater bombs can reach meters in size; such large bombs near the eruption centre at one side suggest the inclination of the eruptive conduct, or an asymmetrical vent-crater system. Inside the crater a 40 m-high dome and a lava flow were extruded during the eruption. Towards the east side of the current Laguna Caliente crater lake, relicts of a 8.5 m thick lava pool are found. During the entire eruptive episode, the acid lake presumably lacked. The eruption is described to be of a mixed type: strombolian, phreatomagmatic, vulcanian and dome extrusion eruptions. Considering the characteristics of this eruption, the height of the eruption column, ejected volume (2.1 x 107  m3), and its presumed duration, a VEI 3 is estimated. The eruptions damaged agricultural activity (including cattle), and forced the spontaneous evacuation of some people. In April 2017 magmatic eruptions followed a decade-long period of intense phreatic activity. These eruptions destroyed the 1953-1955 Dome and led to the complete dry out of Laguna Caliente. Pyroclastic cones and sulphur volcanism manifested at the bottom of the former crater lake bottom. The 2017 eruption severely affected touristic activities at and near Poás, with an estimated economic loss of 20 million dollars. By May-August 2018 Laguna Caliente reappeared. The volcanic hazards related to the three studied historical eruptions are: pyroclastic flows (at least 1 km from the eruptive centre, including reaching the current mirador sector), ballistics (bomb ejections up to 2 km from the emission centre), dispersion and fall of pyroclasts (tens of kms), gas emission and acid rain, dispersed by WSW dominant winds, and lahars in most of the river canyons SW of the volcano.  

Description: Published

Description: 261-299

Description: 1V. Storia eruttiva

Description: Integrating palaeoclimatological proxies and historical records, which is necessary to achieve a more complete understanding of climate impacts on past societies, is a challenging task, often leading to unsatisfactory and even contradictory conclusions. This has until recently been the case for Italy, the heart of the Roman Empire, during the transition between Antiquity and the Middle Ages. In this paper, we present new high-resolution speleothem data from the Apuan Alps (Central Italy). The data document a period of very wet conditions in the sixth c. AD, probably related to synoptic atmospheric conditions similar to a negative phase of the North Atlantic Oscillation. For this century, there also exist a significant number of historical records of extreme hydroclimatic events, previously discarded as anecdotal. We show that this varied evidence reflects the increased frequency of floods and extreme rainfall events in Central and Northern Italy at the time. Moreover, we also show that these unusual hydroclimatic conditions overlapped with the increased presence of "water miracles" in Italian hagiographical accounts and social imagination. The miracles, performed by local Church leaders, strengthened the already growing authority of holy bishops and monks in Italian society during the crucial centuries that followed the "Fall of the Roman Empire". Thus, the combination of natural and historical data allows us to show the degree to which the impact of climate variability on historical societies is determined not by the nature of the climatic phenomena per se, but by the culture and the structure of the society that experienced it.

Description: Published

Description: 25

Description: 5A. Ricerche polari e paleoclima

Description: JCR Journal

Description: Volcano-hydrothermal systems are governed by complex interactions between fluid transport, and geochemical and mechanical processes. Evidence of this close interplay has been testified by distinct spatial and temporal correlations in geochemical and geophysical observations at Vulcano Island (Italy). To understand the interaction between fluid circulation and the geochemical and geophysical manifestations, we perform a parametric study to explore different scenarios by implementing a hydro-geophysical model based on the equations for heat and mass transfer in a porous medium and thermo-poroelastic theory. Numerical simulations allow us to define the controlling role of permeability distribution on the different modeled parameters as well as on the geophysical observables. Changes in the permeability within the highly fractured crater area could be responsible for the fluctuations in gas emission and temperature recorded during the crisis periods, which are accompanied by shallow volcano-seismicity in the absence of significant deformation and gravity variations. Despite the general medium permeability of the volcanic edifice, the presence of more highly permeable pathways, which allow the gas to rapidly escape, as testified by the presence of a well-developed fumarolic field, prevents the pressure buildup at shallow depths.

Description: Published

Description: 179

Description: 4V. Processi pre-eruttivi

Description: JCR Journal

Description: Lahars are rapid flows composed of water and volcaniclastic sediments, which have the potential to impact residential buildings and critical infrastructure as well as to disrupt critical services, especially in the absence of hazard-based land-use planning. Their destructive power is mostly associated with their velocity (related to internal flow properties and topographic interactions) and to their ability to bury buildings and structures (due to deposit thickness). The distance reached by lahars depends on their volume, on sediments/water ratio, as well as on the geometrical properties of the topography where they propagate. Here we present the assessment of risk associated with lahar using Vulcano island (Italy) as a case study. First, we estimated an initial lahar source volume considering the remobilisation by intense rain events of the tephra fallout on the slopes of the La Fossa cone (the active system on the island), where the tephra fallout is associated with the most likely scenario (e.g. long-lasting Vulcanian cycle). Second, we modelled and identified the potential syn-eruptive lahar impact areas on the northern sector of Vulcano, where residential and touristic facilities are located. We tested a range of parameters (e.g., entrainment capability, consolidation of tephra fallout deposit, friction angle) that can influence lahar propagation output both in terms of intensity of the event and extent of the inundation area. Finally, exposure and vulnerability surveys were carried out in order to compile exposure and risk maps for lahar-flow front velocity (semi-quantitative indicator-based risk assessment) and final lahar-deposit thickness (qualitative exposure-based risk assessment). Main outcomes show that the syn-eruptive lahar scenario with medium entrainment capability produces the highest impact associated with building burial by the final lahar deposit. Nonetheless, the syn-eruptive lahar scenario with low entrainment capacity is associated with higher runout and results in the highest impact associated with lahar-flow velocities. Based on our simulations, two critical infrastructures (telecommunication and power plant), as well as the main road crossing the island are exposed to potential lahar impacts (either due to lahar-flow velocity or lahar-deposit thickness or both). These results show that a risk-based spatial planning of the island could represent a valuable strategy to reduce the volcanic risk in the long term.

Description: Published

Description: 9

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: N/A or not JCR

Description: Recent studies point to the sensitivity of mid-latitude winter climate to Arctic sea ice variability. However, there remain contradictory results in terms of character and timing of Northern Hemisphere large-scale circulation features to Arctic sea ice changes. This study assesses the impact of realistic late autumn eastern Arctic sea ice anomalies on atmospheric wintertime circulation at mid-latitudes, pointing to a hidden potential for seasonal predictability. ​Using a dynamical seasonal prediction system, an ensemble of seasonal forecast simulations of 23 historical winter seasons is run with reduced November sea ice cover in the Barents-Kara Seas, and is compared to the respective control seasonal hindcast simulations set. ​A non energy-conserving approach is adopted for achieving the desired sea ice loss, with artificial heat being added conditionally to the ocean surface heat fluxes so as to inhibit the formation of sea ice during November. Our results point to a robust atmospheric circulation response in the North Pacific sector, similar to previous findings on the multidecadal timescale. Specifically, an anticyclonic anomaly at upper and lower levels is identified over the eastern midlatitude North Pacific, leading to dry conditions over the North American southwest coast. The responses are related to a re-organization (weakening) of west-Pacific tropical convection and interactions with the tropical Hadley circulation. ​A possible interaction of the poleward-shifted Pacific eddy-driven jet stream and the Hadley cell is discussed​. ​The winter circulation response in the Euro-Atlantic sector is ephemeral in character and statistically significant in January only, corroborating previous findings of an intermittent and non-stationary Arctic sea ice-NAO link during boreal winter. These results ​aid our understanding of the seasonal impacts of reduced eastern Arctic sea ice on the midlatitude atmospheric circulation with implications for seasonal predictability in wintertime.

Description: Published

Description: 2687–2700

Description: 4A. Oceanografia e clima

Description: JCR Journal

Description: Gender equality is a fundamental human right, embedded into the United Nations Charter (1945). Women still face multiple forms of discrimination, harassment and abuse. Gender equality is foundational to ensuring inclusive sustainable socio-economic development, peace and justice.

Description: Published

Description: 105-126

Description: 1TM. Formazione

Description: 3TM. Comunicazione

Description: Hydrogeoethics is an emergent transdisciplinary field in geosciences focused on ethical research and best practices related to responsible groundwater science and engineering, creating conditions for sustainable water resources management while respecting human needs and environmental dynamics.

Description: Published

Description: 289–292

Description: 1TR. Georisorse

Description: N/A or not JCR

Description: Groundwater close to three municipal solid waste landfll sites in Sicily (southern Italy) was sampled to determine the presence of contaminants and the risk associated with its possible use as drinking and sanitary water. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and metals were investigated. These target compounds are the most common pollutants present in leachates. Risk Assessment Guidance for Superfund (RAGS, US EPA) was used to assess human health risk. Ingestion, dermal, and total exposure to these xenobiotic contaminants in groundwater were evaluated, and the cancer and non-cancer risk indexes were calculated. The results revealed that, while the groundwater complied with Italian Drinking Water Directive 30/2001, it did not comply with the "good environmental state" criteria of Directive 30/2009 at two of the three sites investigated. Worrying results were revealed by the risk assessment at the investigated sites. Cancer and non-cancer risk indexes indicated a probable risk, mainly due to dermal exposure to groundwater. These results underline the importance of assessing the risk for all possible routes, evaluating not only ingestion but also dermal exposure, especially when organic pollutants are present. The results of this study show that human health risk has probably been underestimated in the past, as dermal exposure to organic pollutants has only rarely been evaluated in the literature.

Description: Published

Description: 535–550

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: The island of Ischia, located in the Gulf of Naples, represents an unusual case of resur- gent caldera where small-to-moderate magnitude volcano-tectonic earthquakes generate large damage and catastrophic e ects, as in the case of 4 March 1881 (Imax-VIII-IXMCS) and 28 July 1883 (Imax X-XI MCS) historical earthquakes, and of the recent 21 August 2017 MW=3.9, event. All these earthquakes struck the northern area of the island. With about 65,000 inhabitants, Ischia is a popular touristic destination for thermals baths, host- ing more than 3,000,000 visitors per year, thus representing a high seismic risk area. Assessing its seismic potential appears a fundamental goal and, to this end, the estimate of the magnitude of signi cant historical events and the characterization of their source are crucial. We report here a reassessment of historical data of damage of 1881 and 1883 earth- quakes to evaluate the main source parameters of these events (obtained with the BOXER and EXISM software) and quantitatively compare, for the rst time, the results with the source characteristics, obtained from instrumental data, of the recent 2017 earthquake. The results allowed us to assess the location, as well as the possible dimension and the related maximum magnitude, of the seismogenic structure responsible for such damaging earth- quakes. Our results also provide an additional framework to de ne the mechanisms leading to earthquakes associated with the dynamics of calderas.

Description: Published

Description: 177–201

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: The AD 1761 eruption on Terceira was the onlyhistorical subaerial event on the island and one of the lastrecorded in the Azores. The eruption occurred along the fis-sure zone that crosses the island and produced a trachybasaltlava flow and scoria cones. Small comenditic trachyte lava domes (known as Mistérios Negros) were also thought by some to have formed simultaneously on the eastern flank of Santa Bárbara Volcano. Following a multidisciplinary approach, we combined geological mapping, paleomagnetic, petrographic, mineral and whole-rock geochemical and structural analyses to study this eruption. The paleomagnetic dating method compared geomagnetic vectors (directions and intensities) recorded by both the AD 1761 lava flow and Mistérios Negros domes and revealed that the two events were indeed coeval. Based on new data and interpretation of historical records, we have accordingly reconstructed the AD 1761eruptive dynamics and distinguished three phases: (1) a pre-cursory phase characterized by decreased degassing in the fumarolic field of Pico Alto Volcano and a gradual increase of seismic activity, which marked the intrusion of trachybasalt magma; (2) a first eruptive phase that started with phreatic explosions on the eastern flank of Santa Bárbara Volcano, followed by the inconspicuous effusion of comenditic trachyte (66 wt% SiO2), forming a WNW-ESE-oriented chain of lava domes; and (3) a second eruptive phase on the central part ofthe fissure zone, where a Hawaiian to Strombolian-style erup-tion formed small scoria cones (E-W to ENE-WSW-oriented)and a trachybasalt lava flow (50 wt% SiO2) which buried 27houses in Biscoitos village. Petrological analyses show thatthe two batches of magma were emitted independently without evidence of interaction. We envisage that the dome-forming event was triggered by local stress changes induced by intrusion of the trachybasalt dyke along the fissure zone, which created tensile stress conditions that promoted ascent of comenditic trachyte magma stored beneath Santa Bárbara Volcano.

Description: Published

Description: 22

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: Mt Etna has made headlines over the last weeks and months with spectacular eruptions, some of them highly explosive. This type of paroxysmal eruptive behaviour is characteristic of Etna’s activity over the past few decades and so it is no surprise that Etna is among the most active volcanoes worldwide. Etna is well-known for its extraordinary geology and due to its repeated eruptive activity it provides a continuous supply of new scientific opportunities to understand the inner workings of large basaltic volcanic systems. In addition to its scientific value, Etna is also a world famous tourist attraction and has been listed as a UNESCO World Heritage site in 2013 for its geological and cultural value and not least for its fine agricultural products. Etna’s status as an iconic volcano is not a recent phenomenon; in fact, Etna has been a literary fixture for at least 3000 years, giving rise to many ancient myths and legends that mark it as a special place, deserving of human respect. From the ancient eruptions to the latest events in February–April 2021, people try to explain and understand the processes that occur within and beneath the volcano. In this article, we briefly summarize the recent eruptive activity of Etna as well as the ancient myths and legends that surround this volcano, from the underground forge of Hephaestus to the adventures of Odysseus, all the way to the benefits and dangers the volcano provides to those living on its flanks today.

Description: Published

Description: 141-149

Description: 2TM. Divulgazione Scientifica

Description: N/A or not JCR

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Coenen, A. R., Hu, S. K., Luo, E., Muratore, D., & Weitz, J. S. A primer for microbiome time-series analysis. Frontiers in Genetics, 11, (2020): 310, doi:10.3389/fgene.2020.00310.

Description: Time-series can provide critical insights into the structure and function of microbial communities. The analysis of temporal data warrants statistical considerations, distinct from comparative microbiome studies, to address ecological questions. This primer identifies unique challenges and approaches for analyzing microbiome time-series. In doing so, we focus on (1) identifying compositionally similar samples, (2) inferring putative interactions among populations, and (3) detecting periodic signals. We connect theory, code and data via a series of hands-on modules with a motivating biological question centered on marine microbial ecology. The topics of the modules include characterizing shifts in community structure and activity, identifying expression levels with a diel periodic signal, and identifying putative interactions within a complex community. Modules are presented as self-contained, open-access, interactive tutorials in R and Matlab. Throughout, we highlight statistical considerations for dealing with autocorrelated and compositional data, with an eye to improving the robustness of inferences from microbiome time-series. In doing so, we hope that this primer helps to broaden the use of time-series analytic methods within the microbial ecology research community.

Description: This work was supported by the Simons Foundation (SCOPE award ID 329108) and the National Science Foundation (NSF Bio Oc 1829636).

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ciarletta, D. J., Lorenzo-Trueba, J., & Ashton, A. D. Interaction of sea-level pulses with periodically retreating barrier islands. Frontiers in Earth Science, 7, (2019): 279, doi: 10.3389/feart.2019.00279.

Description: Submerged barrier deposits preserved on continental shelf seabeds provide a record of paleocoastal environmental change from the last glacial maximum through the Holocene. The formation of these offshore deposits is often attributed to intermittent periods of rapidly rising sea levels, especially glacial meltwater pulses, which are expected to lead to partial or complete drowning – overstepping – of migrating barrier islands. However, recent cross-shore modeling and field evidence suggests that even for constant sea-level rise and shelf slope, the internal dynamics of migrating barriers could plausibly drive periodic retreat accompanied by autogenic partial overstepping and deposition of barrier sediment. We hypothesize that the interaction of periodic retreat with changes in external (allogenic) forcing from sea-level rise may create novel retreat responses and corresponding relict barrier deposits. Specifically, we posit that autogenic deposits can be amplified by an increased rate of relative sea-level rise, while in other cases internal dynamics can disrupt or mask the production of allogenic deposits. Here, we model barriers through a range of autogenic–allogenic interactions, exploring how barriers with different inherent autogenic periods respond to discrete, centennial-scale sea-level-rise pulses of variable magnitude and timing within the autogenic transgressive barrier cycle. Our results demonstrate a diversity of depositional signals, where production of relict sands is amplified or suppressed depending on both the barrier’s internal dynamic state and the pulse magnitude. We also show that millennial-scale autogenic periodicity renders barriers vulnerable to complete drowning for relatively low pulse rates of rise (〈15 mm/year).

Description: This material is based upon work supported by the National Science Foundation under Grant No. 1518503, and the American Chemical Society Petroleum Research Fund under Grant No. 58817-DNI8 awarded to JL-T; the views presented herein are solely those of the authors and not of the NSF or the ACS PRF.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kharbush, J. J., Close, H. G., Van Mooy, B. A. S., Arnosti, C., Smittenberg, R. H., Le Moigne, F. A. C., Mollenhauer, G., Scholz-Boettcher, B., Obreht, I., Koch, B. P., Becker, K. W., Iversen, M. H., & Mohr, W. Particulate organic carbon deconstructed: molecular and chemical composition of particulate organic carbon in the ocean. Frontiers in Marine Science, 7, (2020): 518, doi:10.3389/fmars.2020.00518.

Description: The dynamics of the particulate organic carbon (POC) pool in the ocean are central to the marine carbon cycle. POC is the link between surface primary production, the deep ocean, and sediments. The rate at which POC is degraded in the dark ocean can impact atmospheric CO2 concentration. Therefore, a central focus of marine organic geochemistry studies is to improve our understanding of POC distribution, composition, and cycling. The last few decades have seen improvements in analytical techniques that have greatly expanded what we can measure, both in terms of organic compound structural diversity and isotopic composition, and complementary molecular omics studies. Here we provide a brief overview of the autochthonous, allochthonous, and anthropogenic components comprising POC in the ocean. In addition, we highlight key needs for future research that will enable us to more effectively connect diverse data sources and link the identity and structural diversity of POC to its sources and transformation processes.

Description: We thank the Hanse Institute for Advanced Studies (HWK) and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) project number 422798570, as well as the Geochemical Society, for funding which made the workshop possible. CA was additionally supported by OCE-1736772. BV was additionally supported by NSF OCE-1756254.

Description: Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 47(15), (2020): e2020GL087266, doi:10.1029/2020GL087266.

Description: Using a recently compiled global marine data set of dissolved helium isotopes and helium and neon concentrations, we make an estimate of the inventory of hydrothermal 3He in the Southern Ocean to be 4.9 ± 0.6 × 104 moles. Under the assumption that the bulk of the hydrothermally sourced 3He is upwelled there, we use recent estimates of the global hydrothermal 3He flux to determine an e‐folding residence time of 99 ± 18 years, depending on assumptions of water mass and upwelling boundaries. Our estimate is within the broad range of values obtained from recent Southern Ocean circulation models.

Description: This work was funded under the auspices of the U.S. National Science Foundation's Grant OCE‐1756138.

Description: 2021-02-04

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Schlegel, R. W., Oliver, E. C. J., & Chen, K. Drivers of marine heatwaves in the Northwest Atlantic: the role of air-sea interaction during onset and decline. Frontiers in Marine Science, 8, (2021): 627970, https://doi.org/10.3389/fmars.2021.627970

Description: Marine heatwaves (MHWs) are increasing in duration and intensity at a global scale and are projected to continue to increase due to the anthropogenic warming of the climate. Because MHWs may have drastic impacts on fisheries and other marine goods and services, there is a growing interest in understanding the predictability and developing practical predictions of these events. A necessary step toward prediction is to develop a better understanding of the drivers and processes responsible for the development of MHWs. Prior research has shown that air–sea heat flux and ocean advection across sharp thermal gradients are common physical processes governing these anomalous events. In this study we apply various statistical analyses and employ the self-organizing map (SOM) technique to determine specifically which of the many candidate physical processes, informed by a theoretical mixed-layer heat budget, have the most pronounced effect on the onset and/or decline of MHWs on the Northwest Atlantic continental shelf. It was found that latent heat flux is the most common driver of the onset of MHWs. Mixed layer depth (MLD) also strongly modulates the onset of MHWs. During the decay of MHWs, atmospheric forcing does not explain the evolution of the MHWs well, suggesting that oceanic processes are important in the decay of MHWs. The SOM analysis revealed three primary synoptic scale patterns during MHWs: low-pressure cyclonic Autumn-Winter systems, high-pressure anti-cyclonic Spring-Summer blocking, and mild but long-lasting Summer blocking. Our results show that nearly half of past MHWs on the Northwest Atlantic shelf are initiated by positive heat flux anomaly into the ocean, but less than one fifth of MHWs decay due to this process, suggesting that oceanic processes, e.g., advection and mixing are the primary driver for the decay of most MHWs.

Description: RS was supported by the Ocean Frontier Institute International Postdoctoral Fellowship hosted jointly by Dalhousie University and Woods Hole Oceanographic Institution, through an award from the Canada First Research Excellence Fund. EO was funded through the National Sciences and Engineering Research Council of Canada Discovery Grant RGPIN-2018-05255 and Marine Environmental Observation, Prediction, and Response Network Early Career Faculty Grant 1-02-02-059.1. KC was supported by National Oceanic and Atmospheric Administration Climate Program Office Modeling, Analysis, Predictions, and Projections (MAPP) program under grant NA19OAR4320074 and Climate Variability and Predictability (CVP) program under grant NA20OAR4310398.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Mara, P., Edgcomb, V. P., Sehein, T. R., Beaudoin, D., Martinsen, C., Lovely, C., Belcher, B., Cox, R., Curran, M., Farnan, C., Giannini, P., Lott, S., Paquette, K., Pinckney, A., Schafer, N., Surgeon-Rogers, T., & Rogers, D. R. Comparison of oyster aquaculture methods and their potential to from coastal ecosystems. Frontiers in Marine Science, 8,(2021): 633314, https://doi.org/10.3389/fmars.2021.633314.

Description: Coastal ecosystems are impacted by excessive nutrient inputs that cause degradation of water quality and impairments of ecosystem functioning. Regulatory and management efforts to enhance nutrient export from coastal ecosystems include sustainable oyster aquaculture that removes nitrogen in the form of oyster biomass and increases particulate export to underlying sediments where increased organic material may enhance microbial denitrification. To better understand the impacts of oyster aquaculture on nitrogen removal, we examined bacterial processes in sediments underlying three of the most common aquaculture methods that vary in the proximity of oysters to the sediments. Sediment samples underlying sites managed with these different aquaculture methods were examined using the 16S rRNA gene to assess microbial community structure, gene expression analyses to examine nitrogen and sulfur cycling genes, and nitrogen gas flux measurements. All sites were located in the same hydrodynamic setting within Waquoit Bay, MA during 2018 and 2019. Although sediments under the different oyster farming practices showed similar communities, ordination analysis revealed discrete community groups formed along the sampling season. Measured N2 fluxes and expression of key genes involved in denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) increased during mid-summer and into fall in both years primarily under bottom cages. While all three oyster growing methods enhanced nitrogen removal relative to the control site, gene expression data indicate that the nitrogen retaining process of DNRA is particularly enhanced after end of July under bottom cages, and to a lesser extent, under suspended and floating bags. The choice of gear can also potentially increase processes that induce nitrogen retention in the form of ammonia in the underlying sediments over time, thus causing deviations from predicted nitrogen removal. If nitrogen removal is a primary objective, monitoring for these shifts is essential for making decisions about siting and size of aquaculture sites from year to year.

Description: This work was supported by the National Oceanic and Atmospheric Administration and National Estuarine Research Reserve System Science Collaborative, award NAI4NOS4190145 (subaward 3004686666) to DR and VE.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creaive Commons Attribution License. The definitive version was published in Eveleth, R., Glover, D. M., Long, M. C., Lima, I. D., Chase, A. P., & Doney, S. C. . Assessing the skill of a high-resolution marine biophysical model using geostatistical analysis of mesoscale ocean chlorophyll variability from field observations and remote sensing. Frontiers in Marine Science, 8, (2021): 612764, https://doi.org/10.3389/fmars.2021.612764.

Description: High-resolution ocean biophysical models are now routinely being conducted at basin and global-scale, opening opportunities to deepen our understanding of the mechanistic coupling of physical and biological processes at the mesoscale. Prior to using these models to test scientific questions, we need to assess their skill. While progress has been made in validating the mean field, little work has been done to evaluate skill of the simulated mesoscale variability. Here we use geostatistical 2-D variograms to quantify the magnitude and spatial scale of chlorophyll a patchiness in a 1/10th-degree eddy-resolving coupled Community Earth System Model simulation. We compare results from satellite remote sensing and ship underway observations in the North Atlantic Ocean, where there is a large seasonal phytoplankton bloom. The coefficients of variation, i.e., the arithmetic standard deviation divided by the mean, from the two observational data sets are approximately invariant across a large range of mean chlorophyll a values from oligotrophic and winter to subpolar bloom conditions. This relationship between the chlorophyll a mesoscale variability and the mean field appears to reflect an emergent property of marine biophysics, and the high-resolution simulation does poorly in capturing this skill metric, with the model underestimating observed variability under low chlorophyll a conditions such as in the subtropics.

Description: This work was supported in part by the National Aeronautics and Space Administration (NASA) as part of the North Atlantic Aerosol and Marine Ecosystems Study (NAAMES; NASA grant 80NSSC18K0018). The CESM project is supported by the National Science Foundation and the Office of Science (BER) of the United States Department of Energy. Computing resources were provided by the Climate Simulation Laboratory at NCAR’s Computational and Information Systems Laboratory (CISL), sponsored by the National Science Foundation and other agencies. This research was enabled by CISL compute and storage resources.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bond, R. J., Hansel, C. M., & Voelker, B. M. Heterotrophic bacteria exhibit a wide range of rates of extracellular production and decay of hydrogen peroxide. Frontiers in Marine Science, 7, (2020): 72, doi:10.3389/fmars.2020.00072.

Description: Bacteria have been implicated as both a source and sink of hydrogen peroxide (H2O2), a reactive oxygen species which can both impact microbial growth and participate in the geochemical cycling of trace metals and carbon in natural waters. In this study, simultaneous H2O2 production and decay by twelve species of heterotrophic bacteria were evaluated in both batch and flow-through incubations. While wide species-to-species variability of cell-normalized H2O2 decay rate coefficients [2 × 10–8 to 5 × 10–6 hr–1 (cell mL–1)–1] was observed, these rate coefficients were relatively consistent for a given bacterial species. By contrast, observed production rates (below detection limit to 3 × 102 amol cell–1 hr–1) were more variable even for the same species. Variations based on incubation conditions in some bacterial strains suggest that external conditions may impact extracellular H2O2 levels either through increased extracellular production or leakage of intracellular H2O2. Comparison of H2O2 production rates to previously determined superoxide (O2–) production rates suggests that O2– and H2O2 production are not necessarily linked. Rates measured in this study indicate that bacteria could account for a majority of H2O2 decay observed in aqueous systems but likely only make a modest contribution to dark H2O2 production.

Description: This research was supported by NSF grant OCE-1131734/1246174 to BV and CH.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Li, J., Boiteau, R. M., Babcock-Adams, L., Acker, M., Song, Z., McIlvin, M. R., & Repeta, D. J. Element-selective targeting of nutrient metabolites in environmental samples by inductively coupled plasma mass spectrometry and electrospray ionization mass spectrometry. Frontiers in Marine Science, 8, (2021): 630494, https://doi.org/10.3389/fmars.2021.630494.

Description: Metabolites that incorporate elements other than carbon, nitrogen, hydrogen and oxygen can be selectively detected by inductively coupled mass spectrometry (ICPMS). When used in parallel with chromatographic separations and conventional electrospray ionization mass spectrometry (ESIMS), ICPMS allows the analyst to quickly find, characterize and identify target metabolites that carry nutrient elements (P, S, trace metals; “nutrient metabolites”), which are of particular interest to investigations of microbial biogeochemical cycles. This approach has been applied to the study of siderophores and other trace metal organic ligands in the ocean. The original method used mass search algorithms that relied on the ratio of stable isotopologues of iron, copper and nickel to assign mass spectra collected by ESIMS to metabolites carrying these elements detected by ICPMS. However, while isotopologue-based mass assignment algorithms were highly successful in characterizing metabolites that incorporate some trace metals, they do not realize the whole potential of the ICPMS/ESIMS approach as they cannot be used to assign the molecular ions of metabolites with monoisotopic elements or elements for which the ratio of stable isotopes is not known. Here we report a revised ICPMS/ESIMS method that incorporates a number of changes to the configuration of instrument hardware that improves sensitivity of the method by a factor of 4–5, and allows for more accurate quantitation of metabolites. We also describe a new suite of mass search algorithms that can find and characterize metabolites that carry monoisotopic elements. We used the new method to identify siderophores in a laboratory culture of Vibrio cyclitrophicus and a seawater sample collected in the North Pacific Ocean, and to assign molecular ions to monoisotopic cobalt and iodine nutrient metabolites in extracts of a laboratory culture of the marine cyanobacterium Prochorococcus MIT9215.

Description: This work was generously supported by the National Science Foundation grant OCE-1829761 to RB and OCE-1356747 and -1736280 to DR. DR also received generous support from the Simons Foundation Life Sciences Project Award 49476.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bernhard, J. M., Wit, J. C., Starczak, V. R., Beaudoin, D. J., Phalen, W. G., & McCorkle, D. C. Impacts of multiple stressors on a benthic foraminiferal community: a long-term experiment assessing response to ocean acidification, hypoxia and warming. Frontiers in Marine Science, 8, (2021): 643339, https://doi.org/10.3389/fmars.2021.643339.

Description: Ocean chemistry is changing as a result of human activities. Atmospheric carbon dioxide (CO2) concentrations are increasing, causing an increase in oceanic pCO2 that drives a decrease in oceanic pH, a process called ocean acidification (OA). Higher CO2 concentrations are also linked to rising global temperatures that can result in more stratified surface waters, reducing the exchange between surface and deep waters; this stronger stratification, along with nutrient pollution, contributes to an expansion of oxygen-depleted zones (so called hypoxia or deoxygenation). Determining the response of marine organisms to environmental changes is important for assessments of future ecosystem functioning. While many studies have assessed the impact of individual or paired stressors, fewer studies have assessed the combined impact of pCO2, O2, and temperature. A long-term experiment (∼10 months) with different treatments of these three stressors was conducted to determine their sole or combined impact on the abundance and survival of a benthic foraminiferal community collected from a continental-shelf site. Foraminifera are well suited to such study because of their small size, relatively rapid growth, varied mineralogies and physiologies. Inoculation materials were collected from a ∼77-m deep site south of Woods Hole, MA. Very fine sediments (〈53 μm) were used as inoculum, to allow the entire community to respond. Thirty-eight morphologically identified taxa grew during the experiment. Multivariate statistical analysis indicates that hypoxia was the major driving factor distinguishing the yields, while warming was secondary. Species responses were not consistent, with different species being most abundant in different treatments. Some taxa grew in all of the triple-stressor samples. Results from the experiment suggest that foraminiferal species’ responses will vary considerably, with some being negatively impacted by predicted environmental changes, while other taxa will tolerate, and perhaps even benefit, from deoxygenation, warming and OA.

Description: This work was supported by the US NSF SEES-OA grant OCE-1219948 to JB and the Investment in Science Program at WHOI. DM also received support from the NSF Independent Research and Development Program.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Meiling, S. S., Muller, E. M., Lasseigne, D., Rossin, A., Veglia, A. J., MacKnight, N., Dimos, B., Huntley, N., Correa, A. M. S., Smith, T. B., Holstein, D. M., Mydlarz, L. D., Apprill, A., & Brandt, M. E. Variable species responses to experimental stony coral tissue loss disease (SCTLD) exposure. Frontiers in Marine Science, 8, (2021): 670829, https://doi.org/10.3389/fmars.2021.670829.

Description: Stony coral tissue loss disease (SCTLD) was initially documented in Florida in 2014 and outbreaks with similar characteristics have since appeared in disparate areas throughout the northern Caribbean, causing significant declines in coral communities. SCTLD is characterized by focal or multifocal lesions of denuded skeleton caused by rapid tissue loss and affects at least 22 reef-building species of Caribbean corals. A tissue-loss disease consistent with the case definition of SCTLD was first observed in the U.S. Virgin Islands (USVI) in January of 2019 off the south shore of St. Thomas at Flat Cay. The objective of the present study was to characterize species susceptibility to the disease present in St. Thomas in a controlled laboratory transmission experiment. Fragments of six species of corals (Colpophyllia natans, Montastraea cavernosa, Orbicella annularis, Porites astreoides, Pseudodiploria strigosa, and Siderastrea siderea) were simultaneously incubated with (but did not physically contact) SCTLD-affected colonies of Diploria labyrinthiformis and monitored for lesion appearance over an 8 day experimental period. Paired fragments from each corresponding coral genotype were equivalently exposed to apparently healthy colonies of D. labyrinthiformis to serve as controls; none of these fragments developed lesions throughout the experiment. When tissue-loss lesions appeared and progressed in a disease treatment, the affected coral fragment, and its corresponding control genet, were removed and preserved for future analysis. Based on measures including disease prevalence and incidence, relative risk of lesion development, and lesion progression rates, O. annularis, C. natans, and S. siderea showed the greatest susceptibility to SCTLD in the USVI. These species exhibited earlier average development of lesions, higher relative risk of lesion development, greater lesion prevalence, and faster lesion progression rates compared with the other species, some of which are considered to be more susceptible based on field observations (e.g., P. strigosa). The average transmission rate in the present study was comparable to tank studies in Florida, even though disease donor species differed. Our findings suggest that the tissue loss disease affecting reefs of the USVI has a similar epizootiology to that observed in other regions, particularly Florida.

Description: This work was supported by the National Science Foundation (Biological Oceanography) award number 1928753 to MB and TS, 1928609 to AC, 1928817 to EM, 19228771 to LM, 1927277 to DH, and 1928761 to AA as well as by VI EPSCoR (NSF #0814417 and NSF #1946412).

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bejannin, S., Tamborski, J. J., van Beek, P., Souhaut, M., Stieglitz, T., Radakovitch, O., Claude, C., Conan, P., Pujo-Pay, M., Crispi, O., Le Roy, E., & Estournel, C. Nutrient fluxes associated with submarine groundwater discharge from karstic coastal aquifers (Côte Bleue, French Mediterranean coastline). Frontiers in Environmental Science, 7, (2020): 205, doi: 10.3389/fenvs.2019.00205.

Description: Determination of submarine groundwater discharge (SGD) from karstic coastal aquifers is important to constrain hydrological and biogeochemical cycles. However, SGD quantification using commonly employed geochemical methods can be difficult to constrain under the presence of large riverine inputs, and is further complicated by the determination of the karstic groundwater endmember. Here, we investigated a coastal region where groundwater discharges from a karstic aquifer system using airborne thermal infrared mapping and geochemical sampling conducted along offshore transects. We report radium data (223Ra, 224Ra, 228Ra) that we used to derive fluxes (water, nutrients) associated with terrestrial groundwater discharge and/or seawater circulation through the nearshore permeable sediments and coastal aquifer. Field work was conducted at different periods of the year to study the temporal variability of the chemical fluxes. Offshore transects of 223Ra and 224Ra were used to derive horizontal eddy diffusivity coefficients that were subsequently combined with surface water nutrient gradients (NO2− + NO3−, DSi) to determine the net nutrient fluxes from SGD. The estimated DSi and (NO2− + NO3−) fluxes are 6.2 ± 5.0 *103 and 4.0 ± 2.0 *103 mol d−1 per km of coastline, respectively. We attempted to further constrain these SGD fluxes by combining horizontal eddy diffusivity and 228Ra gradients. However, SGD endmember selection in this area (terrestrial groundwater discharge vs. porewater) adds further uncertainty to the flux calculation and thus prevented us from calculating a reliable flux using this latter method. Additionally, the relatively long half-life of 228Ra (5.75 y) makes it sensitive to specific circulation patterns in this coastal region, including sporadic intrusions of Rhône river waters that impact both the 228Ra and nutrient surface water distributions. We show that SGD nutrient fluxes locally reach up to 20 times the nutrient fluxes from a small river (Huveaune River). On a regional scale, DSi fluxes driven by SGD vary between 0.1 and 1.4% of the DSi inputs of the Rhône River, while the (NO2− + NO3−) fluxes driven by SGD on this 22 km long coastline are between 0.1 and 0.3% of the Rhône River inputs, the largest river that discharges into the Mediterranean Sea. Interestingly, the nutrient fluxes reported here are similar in magnitude compared with the fluxes quantified along the sandy beach of La Franqui, in the western Gulf of Lions (Tamborski et al., 2018), despite the different lithology of the two areas (karst systems vs. unconsolidated sediment).

Description: The Ph.D. thesis fellowship of SB and the postdoctoral fellowship of JT were supported by FEDER funded by Europe and Région Occitanie Pyrénées-Méditerranée (SELECT project). This project was funded by (i) ANR-MED-SGD (ANR-15-CE01-0004; PB) and (ii) CNES for funding the airborne TIR images acquired in 2012 as part of the Geomether project (PI: Pascal Allemand, PB being responsible for the acquisition of TIR images in that project).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cowley, R., Killick, R. E., Boyer, T., Gouretski, V., Reseghetti, F., Kizu, S., Palmer, M. D., Cheng, L., Storto, A., Le Menn, M., Simoncelli, S., Macdonald, A. M., & Domingues, C. M. International Quality-Controlled Ocean Database (IQuOD) v0.1: the temperature uncertainty specification. Frontiers in Marine Science, 8, (2021): 689695, https://doi.org/10.3389/fmars.2021.689695.

Description: Ocean temperature observations are crucial for a host of climate research and forecasting activities, such as climate monitoring, ocean reanalysis and state estimation, seasonal-to-decadal forecasts, and ocean forecasting. For all of these applications, it is crucial to understand the uncertainty attached to each of the observations, accounting for changes in instrument technology and observing practices over time. Here, we describe the rationale behind the uncertainty specification provided for all in situ ocean temperature observations in the International Quality-controlled Ocean Database (IQuOD) v0.1, a value-added data product served alongside the World Ocean Database (WOD). We collected information from manufacturer specifications and other publications, providing the end user with uncertainty estimates based mainly on instrument type, along with extant auxiliary information such as calibration and collection method. The provision of a consistent set of observation uncertainties will provide a more complete understanding of historical ocean observations used to examine the changing environment. Moving forward, IQuOD will continue to work with the ocean observation, data assimilation and ocean climate communities to further refine uncertainty quantification. We encourage submissions of metadata and information about historical practices to the IQuOD project and WOD.

Description: This work was supported by the Scientific Committee on Oceanic Research (SCOR) Working Group 148, funded by national SCOR committees and a grant to SCOR from the U.S. National Science Foundation (Grant OCE-1546580); and the Intergovernmental Oceanographic Commission of UNESCO/International Oceanographic Data and Information Exchange (IOC/IODE) IQuOD Steering Group. RC was supported through funding from the Earth Systems and Climate Change Hub of the Australian Government's National Environmental Science Program. RK and MP were supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra. CD was supported by the Australian Research Council (Discovery Grant DP160103130), ARC Centre of Excellence for Climate Extremes (CE170100023) and by the Natural Environment Research Council (TICTOC, NE/P019293/1). AM's contribution was supported by National Science Foundation grant OCE#-1923387 and National Oceanographic and Atmospheric Administration grant #NA16OAR4310172.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Howell, K. L., Hilario, A., Allcock, A. L., Bailey, D. M., Baker, M., Clark, M. R., Colaco, A., Copley, J., Cordes, E. E., Danovaro, R., Dissanayake, A., Escobar, E., Esquete, P., Gallagher, A. J., Gates, A. R., Gaudron, S. M., German, C. R., Gjerde, K. M., Higgs, N. D., Le Bris, N., Levin, L. A., Manea, E., McClain, C., Menot, L., Mestre, N. C., Metaxas, A., Milligan, R. J., Muthumbi, A. W. N., Narayanaswamy, B. E., Ramalho, S. P., Ramirez-Llodra, E., Robson, L. M., Rogers, A. D., Sellanes, J., Sigwart, J. D., Sink, K., Snelgrove, P. V. R., Stefanoudis, P., V., Sumida, P. Y., Taylor, M. L., Thurber, A. R., Vieira, R. P., Watanabe, H. K., Woodall, L. C., & Xavier, J. R. A blueprint for an inclusive, global deep-sea ocean decade field program. Frontiers in Marine Science, 7, (2020): 584861, doi:10.3389/fmars.2020.584861.

Description: The ocean plays a crucial role in the functioning of the Earth System and in the provision of vital goods and services. The United Nations (UN) declared 2021–2030 as the UN Decade of Ocean Science for Sustainable Development. The Roadmap for the Ocean Decade aims to achieve six critical societal outcomes (SOs) by 2030, through the pursuit of four objectives (Os). It specifically recognizes the scarcity of biological data for deep-sea biomes, and challenges the global scientific community to conduct research to advance understanding of deep-sea ecosystems to inform sustainable management. In this paper, we map four key scientific questions identified by the academic community to the Ocean Decade SOs: (i) What is the diversity of life in the deep ocean? (ii) How are populations and habitats connected? (iii) What is the role of living organisms in ecosystem function and service provision? and (iv) How do species, communities, and ecosystems respond to disturbance? We then consider the design of a global-scale program to address these questions by reviewing key drivers of ecological pattern and process. We recommend using the following criteria to stratify a global survey design: biogeographic region, depth, horizontal distance, substrate type, high and low climate hazard, fished/unfished, near/far from sources of pollution, licensed/protected from industry activities. We consider both spatial and temporal surveys, and emphasize new biological data collection that prioritizes southern and polar latitudes, deeper (〉 2000 m) depths, and midwater environments. We provide guidance on observational, experimental, and monitoring needs for different benthic and pelagic ecosystems. We then review recent efforts to standardize biological data and specimen collection and archiving, making “sampling design to knowledge application” recommendations in the context of a new global program. We also review and comment on needs, and recommend actions, to develop capacity in deep-sea research; and the role of inclusivity - from accessing indigenous and local knowledge to the sharing of technologies - as part of such a global program. We discuss the concept of a new global deep-sea biological research program ‘Challenger 150,’ highlighting what it could deliver for the Ocean Decade and UN Sustainable Development Goal 14.

Description: Development of this paper was supported by funding from the Scientific Committee on Oceanic Research (SCOR) awarded to KH and AH as working group 159 co-chairs. KH, BN, and KS are supported by the UKRI funded One Ocean Hub NE/S008950/1. AH work is supported by the CESAM (UIDP/50017/2020 + 1432 UIDB/50017/2020) that is funded by Fundação para a Ciência e a Tecnologia (FCT)/MCTES through national funds. AA is supported by Science Foundation Ireland and the Marine Institute under the Investigators Program Grant Number SFI/15/IA/3100 co-funded under the European Regional Development Fund 2014–2020. AC is supported through the FunAzores -ACORES 01-0145-FEDER-000123 grant and by FCT through strategic project UID/05634/2020 and FCT and Direção-Geral de Politica do Mar (DGPM) through the project Mining2/2017/005. PE is funded by national funds (OE), through FCT in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. SG research is supported by CNRS funds. CG is supported by an Independent Study Award and the Investment in Science Fund at WHOI. KG gratefully acknowledges support from Synchronicity Earth. LL is funded by the NOAA Office of Ocean Exploration and Research (NA19OAR0110305) and the US National Science Foundation (OCE 1634172). NM is supported by FCT and DGPM, through the project Mining2/2017/001 and the FCT grants CEECIND/00526/2017, UIDB/00350/2020 + UIDP/00350/2020. SR is funded by the FCTgrant CEECIND/00758/2017. JS is supported by ANID FONDECYT #1181153 and ANID Millennium Science Initiative Program #NC120030. JX research is funded by the European Union’s Horizon 2020 research and innovation program through the SponGES project (grant agreement no. 679849) and further supported by national funds through FCT within the scope of UIDB/04423/2020 and UIDP/04423/2020. The Natural Sciences and Engineering Council of Canada supports AM and PVRS. MB and the Deep-Ocean Stewardship Initiative are supported by Arcadia - A charitable fund of Lisbet Rausing and Peter Baldwin. BN work is supported by the NERC funded Arctic PRIZE NE/P006302/1.

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Clayton, S., Alexander, H., Graff, J. R., Poulton, N. J., Thompson, L. R., Benway, H., Boss, E., & Martiny, A. Bio-GO-SHIP: the time is right to establish global repeat sections of ocean biology. Frontiers in Marine Science, 8, (2022): 767443, https://doi.org/10.3389/fmars.2021.767443.

Description: In this article, we present Bio-GO-SHIP, a new ocean observing program that will incorporate sustained and consistent global biological ocean observations into the Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP). The goal of Bio-GO-SHIP is to produce systematic and consistent biological observations during global ocean repeat hydrographic surveys, with a particular focus on the planktonic ecosystem. Ocean plankton are an essential component of the earth climate system, form the base of the oceanic food web and thereby play an important role in influencing food security and contributing to the Blue Economy. Despite its importance, ocean biology is largely under-sampled in time and space compared to physical and chemical properties. This lack of information hampers our ability to understand the role of plankton in regulating biogeochemical processes and fueling higher trophic levels, now and in future ocean conditions. Traditionally, many of the methods used to quantify biological and ecosystem essential ocean variables (EOVs), measures that provide valuable information on the ecosystem, have been expensive and labor- and time-intensive, limiting their large-scale deployment. In the last two decades, new technologies have been developed and matured, making it possible to greatly expand our biological ocean observing capacity. These technologies, including cell imaging, bio-optical sensors and 'omic tools, can be combined to provide overlapping measurements of key biological and ecosystem EOVs. New developments in data management and open sharing can facilitate meaningful synthesis and integration with concurrent physical and chemical data. Here we outline how Bio-GO-SHIP leverages these technological advances to greatly expand our knowledge and understanding of the constituents and function of the global ocean plankton ecosystem.

Description: The Bio-GO-SHIP pilot program was funded under the National Oceanographic Partnership Program as an inter-agency partnership between NOAA and NASA, with the US Integrated Ocean Observing System and NOAA's Global Ocean Monitoring and Observing program (HA, SC, JG, AM, and NP). HA was supported by a WHOI Independent Research and Development award. AM was supported by funding from NSF OCE-1848576 and 1948842 and NASA 80NSSC21K1654. JG was funded by NASA from grants 80NSSC17K0568 and NNX15AAF30G. LT was supported by award NA06OAR4320264 06111039 to the Northern Gulf Institute by NOAA's Office of Oceanic and Atmospheric Research, U.S. Department of Commerce.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Petrillo, C., Castaldi, S., Lanzilli, M., Selci, M., Cordone, A., Giovannelli, D., & Isticato, R. Genomic and physiological characterization of Bacilli isolated from salt-pans with plant growth promoting features. Frontiers in Microbiology, 12, (2021): 715678, https://doi.org/10.3389/fmicb.2021.715678.

Description: Massive application of chemical fertilizers and pesticides has been the main strategy used to cope with the rising crop demands in the last decades. The indiscriminate use of chemicals while providing a temporary solution to food demand has led to a decrease in crop productivity and an increase in the environmental impact of modern agriculture. A sustainable alternative to the use of agrochemicals is the use of microorganisms naturally capable of enhancing plant growth and protecting crops from pests known as Plant-Growth-Promoting Bacteria (PGPB). Aim of the present study was to isolate and characterize PGPB from salt-pans sand samples with activities associated to plant fitness increase. To survive high salinity, salt-tolerant microbes produce a broad range of compounds with heterogeneous biological activities that are potentially beneficial for plant growth. A total of 20 halophilic spore-forming bacteria have been screened in vitro for phyto-beneficial traits and compared with other two members of Bacillus genus recently isolated from the rhizosphere of the same collection site and characterized as potential biocontrol agents. Whole-genome analysis on seven selected strains confirmed the presence of numerous gene clusters with PGP and biocontrol functions and of novel secondary-metabolite biosynthetic genes, which could exert beneficial impacts on plant growth and protection. The predicted biocontrol potential was confirmed in dual culture assays against several phytopathogenic fungi and bacteria. Interestingly, the presence of predicted gene clusters with known biocontrol functions in some of the isolates was not predictive of the in vitro results, supporting the need of combining laboratory assays and genome mining in PGPB identification for future applications.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Lamborg, C. H., Hansel, C. M., Bowman, K. L., Voelker, B. M., Marsico, R. M., Oldham, V. E., Swarr, G. J., Zhang, T., & Ganguli, P. M. Dark reduction drives evasion of mercury from the ocean. Frontiers in Environmental Chemistry, 2, (2021): 659085, https://doi.org/10.3389/fenvc.2021.659085.

Description: Much of the surface water of the ocean is supersaturated in elemental mercury (Hg0) with respect to the atmosphere, leading to sea-to-air transfer or evasion. This flux is large, and nearly balances inputs from the atmosphere, rivers and hydrothermal vents. While the photochemical production of Hg0 from ionic and methylated mercury is reasonably well-studied and can produce Hg0 at fairly high rates, there is also abundant Hg0 in aphotic waters, indicating that other important formation pathways exist. Here, we present results of gross reduction rate measurements, depth profiles and diel cycling studies to argue that dark reduction of Hg2+ is also capable of sustaining Hg0 concentrations in the open ocean mixed layer. In locations where vertical mixing is deep enough relative to the vertical penetration of UV-B and photosynthetically active radiation (the principal forms of light involved in abiotic and biotic Hg photoreduction), dark reduction will contribute the majority of Hg0 produced in the surface ocean mixed layer. Our measurements and modeling suggest that these conditions are met nearly everywhere except at high latitudes during local summer. Furthermore, the residence time of Hg0 in the mixed layer with respect to evasion is longer than that of redox, a situation that allows dark reduction-oxidation to effectively set the steady-state ratio of Hg0 to Hg2+ in surface waters. The nature of these dark redox reactions in the ocean was not resolved by this study, but our experiments suggest a likely mechanism or mechanisms involving enzymes and/or important redox agents such as reactive oxygen species and manganese (III).

Description: This work was supported by NSF Grant OCE-1355720 (to CH, CL, and BV).

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Barry, P. H., De Moor, J. M., Chiodi, A., Aguilera, F., Hudak, M. R., Bekaert, D. V., Turner, S. J., Curtice, J., Seltzer, A. M., Jessen, G. L., Osses, E., Blamey, J. M., Amenabar, M. J., Selci, M., Cascone, M., Bastianoni, A., Nakagawa, M., Filipovich, R., Bustos, E., Schrenk, M. O. , Buongiorno, J., Ramírez, C. J., Rogers, T. J., Lloyd, K. G. & Giovannelli, D. The helium and carbon isotope characteristics of the Andean Convergent Margin. Frontiers in Earth Science, 10, (2022): 897267, https://doi.org/10.3389/feart.2022.897267.

Description: Subduction zones represent the interface between Earth’s interior (crust and mantle) and exterior (atmosphere and oceans), where carbon and other volatile elements are actively cycled between Earth reservoirs by plate tectonics. Helium is a sensitive tracer of volatile sources and can be used to deconvolute mantle and crustal sources in arcs; however it is not thought to be recycled into the mantle by subduction processes. In contrast, carbon is readily recycled, mostly in the form of carbon-rich sediments, and can thus be used to understand volatile delivery via subduction. Further, carbon is chemically-reactive and isotope fractionation can be used to determine the main processes controlling volatile movements within arc systems. Here, we report helium isotope and abundance data for 42 deeply-sourced fluid and gas samples from the Central Volcanic Zone (CVZ) and Southern Volcanic Zone (SVZ) of the Andean Convergent Margin (ACM). Data are used to assess the influence of subduction parameters (e.g., crustal thickness, subduction inputs, and convergence rate) on the composition of volatiles in surface volcanic fluid and gas emissions. He isotopes from the CVZ backarc range from 0.1 to 2.6 RA (n = 23), with the highest values in the Puna and the lowest in the Sub-Andean foreland fold-and-thrust belt. Atmosphere-corrected He isotopes from the SVZ range from 0.7 to 5.0 RA (n = 19). Taken together, these data reveal a clear southeastward increase in 3He/4He, with the highest values (in the SVZ) falling below the nominal range associated with pure upper mantle helium (8 ± 1 RA), approaching the mean He isotope value for arc gases of (5.4 ± 1.9 RA). Notably, the lowest values are found in the CVZ, suggesting more significant crustal inputs (i.e., assimilation of 4He) to the helium budget. The crustal thickness in the CVZ (up to 70 km) is significantly larger than in the SVZ, where it is just ∼40 km. We suggest that crustal thickness exerts a primary control on the extent of fluid-crust interaction, as helium and other volatiles rise through the upper plate in the ACM. We also report carbon isotopes from (n = 11) sites in the CVZ, where δ13C varies between −15.3‰ and −1.2‰ [vs. Vienna Pee Dee Belemnite (VPDB)] and CO2/3He values that vary by over two orders of magnitude (6.9 × 108–1.7 × 1011). In the SVZ, carbon isotope ratios are also reported from (n = 13) sites and vary between −17.2‰ and −4.1‰. CO2/3He values vary by over four orders of magnitude (4.7 × 107–1.7 × 1012). Low δ13C and CO2/3He values are consistent with CO2 removal (e.g., calcite precipitation and gas dissolution) in shallow hydrothermal systems. Carbon isotope fractionation modeling suggests that calcite precipitation occurs at temperatures coincident with the upper temperature limit for life (122°C), suggesting that biology may play a role in C-He systematics of arc-related volcanic fluid and gas emissions.

Description: This work was principally supported by the NSF-FRES award 2121637 to PB, KL, and JM. Field work was also supported by award G-2016-7206 from the Alfred P. Sloan Foundation and the Deep Carbon Observatory to PB, KL, DG, and JM. Additional support came from The National Fund for Scientific and Technological Development of Chile (FONDECYT) Grant 11191138 (The National Research and Development Agency of Chile, ANID Chile), and COPAS COASTAL ANID FB210021 to GJ. DG was partially supported by funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program Grant Agreement No. 948972—COEVOLVE—ERC-2020-STG.

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Rathore, S., Goyal, R., Jangir, B., Ummenhofer, C., Feng, M., & Mishra, M. Interactions between a marine heatwave and tropical cyclone Amphan in the Bay of Bengal in 2020. Frontiers in Climate, 4, (2022): 861477, https://doi.org/10.3389/fclim.2022.861477.

Description: Interactions are diagnosed between a marine heatwave (MHW) event and tropical super cyclone Amphan in the Bay of Bengal. In May 2020, an MHW developed in the Bay of Bengal driven by coupled ocean-atmosphere processes which included shoaling of the mixed layer depth due to reduced wind speed, increased net surface shortwave radiation flux into the ocean, increased upper ocean stratification, and increased sub-surface warming. Ocean temperature, rather than salinity, dominated the stratification that contributed to the MHW development and the subsurface ocean warming that also increased tropical cyclone heat potential. The presence of this strong MHW with sea surface temperature anomalies 〉2.5°C in the western Bay of Bengal coincided with the cyclone track and facilitated the rapid intensification of tropical cyclone Amphan to a super cyclone in just 24 h. This rapid intensification of a short-lived tropical cyclone, with a lifespan of 5 days over the ocean, is unprecedented in the Bay of Bengal during the pre-monsoon period (March-May). As the cyclone approached landfall in northern India, the wind-induced mixing deepened the mixed layer, cooled the ocean's surface, and reduced sub-surface warming in the bay, resulting in the demise of the MHW. This study provides new perspectives on the interactions between MHWs and tropical cyclones that could aid in improving the current understanding of compound extreme events that have severe socio-economic consequences in affected countries.

Description: CU acknowledges support from the James E. and Barbara V. Moltz Fellowship for Climate-Related Research and the Independent Research & Development Program at WHOI. MF was supported by the Centre for Southern Hemisphere Oceans Research (CSHOR), which is a joint initiative between the Qingdao National Laboratory for Marine Science and Technology (QNLM), CSIRO, University of New South Wales, and the University of Tasmania.

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Großelindemann, H., Ryan, S., Ummenhofer, C., Martin, T., & Biastoch, A. Marine Heatwaves and their depth structures on the Northeast U.S. continental shelf. Frontiers in Climate, 4, (2022): 857937, https://doi.org/10.3389/fclim.2022.857937.

Description: Marine Heatwaves (MHWs) are ocean extreme events, characterized by anomalously high temperatures, which can have significant ecological impacts. The Northeast U.S. continental shelf is of great economical importance as it is home to a highly productive ecosystem. Local warming rates exceed the global average and the region experienced multiple MHWs in the last decade with severe consequences for regional fisheries. Due to the lack of subsurface observations, the depth-extent of MHWs is not well-known, which hampers the assessment of impacts on pelagic and benthic ecosystems. This study utilizes a global ocean circulation model with a high-resolution (1/20°) nest in the Atlantic to investigate the depth structure of MHWs and associated drivers on the Northeast U.S. continental shelf. It is shown that MHWs exhibit varying spatial extents, with some only occurring at depth. The highest intensities are found around 100 m depth with temperatures exceeding the climatological mean by up to 7°C, while surface intensities are typically smaller (around 3°C). Distinct vertical structures are associated with different spatial MHW patterns and drivers. Investigation of the co-variability of temperature and salinity reveals that over 80% of MHWs at depth (〉50 m) coincide with extreme salinity anomalies. Two case studies provide insight into opposing MHW patterns at the surface and at depth, being forced by anomalous air-sea heat fluxes and Gulf Stream warm core ring interaction, respectively. The results highlight the importance of local ocean dynamics and the need to realistically represent them in climate models.

Description: This work was supported by a DAAD RISE Worldwide fellowship (to HG), a Feodor-Lynen Fellowship by the Alexander von Humboldt Foundation and the WHOI Postdoctoral Scholar program (to SR), and the James E. and Barbara V. Moltz Fellowship for Climate-Related Research (to CU). Franziska Schwarzkopf performed the integration of the OGCM simulations, which was performed on the Earth System Modeling Project (ESM) partition of the supercomputer JUWELS at the Jülich Supercomputing Centre (JSC).

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kourantidou, M., & Jin, D. Mesopelagic-epipelagic fish nexus in viability and feasibility of commercial-scale mesopelagic fisheries. Natural Resource Modeling, 35(4), (2022): e12350, https://doi.org/10.1111/nrm.12350.

Description: While considerable scientific uncertainties persist for mesopelagic ecosystems, the fishing industry has developed a great interest in commercial exploitation with improved technologies as part of their search for new sources of feed for fishmeal and fish oil for aquaculture, which will intensify with the planet's growing population. The multiple uncertainties surrounding the ecosystem structure and particularly the size of biomass, hinder a good understanding of the risks associated with large-scale exploitation, which is needed for a management framework for sustainable ocean uses. Despite concerns regarding irreversible losses triggered by commercial fishing, work exploring the vulnerability of mesopelagic fish to harvesting is largely missing. This study investigates the economic feasibility of mesopelagic fishing which is the primary driver for any possible future expansion. Using very limited information currently available, we conduct a high-level assessment focusing on key ecological and economic interactions and develop an initial understanding of the economic feasibility of commercial harvesting for mesopelagic fish in the coming years. We conduct simulations using a classical bioeconomic model that captures two species groups, mesopelagic and epipelagic fish, using a wide range of price and cost parameters. We analyze different scenarios for the economic profitability of the fishery in a regional fishery management context. The results of our study highlight the importance of better understanding key biological and ecological mechanisms and parameters which can in turn help inform policies aimed at protecting the mesopelagic.

Description: This study is supported by WHOI's Ocean Twilight Zone program which is part of the Audacious Project, a collaborative endeavor, housed at TED.

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gawarkiewicz, G., Chen, K., Forsyth, J., Bahr, F., Mercer, A. M., Ellertson, A., Fratantoni, P., Seim, H., Haines, S., & Han, L. Characteristics of an advective Marine Heatwave in the Middle Atlantic Bight in early 2017. Frontiers in Marine Science, 6, (2019): 712, doi: 10.3389/fmars.2019.00712.

Description: There has been wide interest in Marine Heatwaves and their ecological consequences in recent years. Most analyses have focused on remotely sensed sea surface temperature data due to the temporal and spatial coverage it provides in order to establish the presence and duration of Heatwaves. Using hydrographic data from a variety of sources, we show that an advective Marine Heatwave was initiated by an event in late December of 2016 south of New England, with temperature anomalies measuring up to 6°C and salinity anomalies exceeding 1 PSU. Similar features were observed off of New Jersey in February 2017, and are associated with the Shelfbreak Front migrating from its normal position to mid-shelf or further onshore. Shelf water of 34 PSU was observed just north of Cape Hatteras at the 30 m isobath and across the continental shelf in late April 2017. These observations reveal that the 2017 Marine Heatwave was associated with a strong positive salinity anomaly, that its total duration was approximately 4 months, and its advective path extended roughly 850 km along the length of the continental shelf in the Middle Atlantic Bight. The southward advective velocity implied by the arrival north of Cape Hatteras is consistent with previous estimates of alongshelf velocity for the region. The origin of this Marine Heatwave is likely related to cross-shelf advection driven by the presence of a Warm Core Ring adjacent to the shelfbreak south of New England.

Description: GG was supported by the van Beuren Charitable Foundation, the National Science Foundation under grants OCE-1657853 and OCE-1558521 as well as a Senior Scientist Chair from the Woods Hole Oceanographic Institution. KC was supported by the National Science Foundation under grants OCE-1558960 and OCE-1634094. JF was supported by the National Science Foundation OCE-1634094. AM and AE were supported by the van Beuren Charitable Foundation. HS, SH, and LH were supported by the National Science Foundation OCE-1558920.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ryan, S., Hellmer, H. H., Janout, M., Darelius, E., Vignes, L., & Schroeder, M. Exceptionally warm and prolonged flow of warm deep water toward the Filchner-Ronne Ice Shelf in 2017. Geophysical Research Letters, 47(13),(2020): e2020GL088119, doi:10.1029/2020GL088119.

Description: The Filchner‐Ronne Ice Shelf, fringing the southern Weddell Sea, is Antarctica's second largest ice shelf. At present, basal melt rates are low due to active dense water formation; however, model projections suggest a drastic increase in the future due to enhanced inflow of open‐ocean warm water. Mooring observations from 2014 to 2016 along the eastern flank of the Filchner Trough (76°S) revealed a distinct seasonal cycle with inflow if Warm Deep Water during summer and autumn. Here we present extended time series showing an exceptionally warm and long inflow in 2017, with maximum temperatures exceeding 0.5°C. Warm temperatures persisted throughout winter, associated with a fresh anomaly, which lead to a change in stratification over the shelf, favoring an earlier inflow in the following summer. We suggest that the fresh anomaly developed upstream after anomalous summer sea ice melting and contributed to a shoaling of the shelf break thermocline.

Description: The authors would like to express their gratitude to the officers and crews of RV Polarstern (cruises PS92 [Grant AWI_PS82_02], PS96 [Grant AWI_PS96_01], and PS111 [Grant AWI_PS111_01]), RRS Ernest Shackleton (Cruise ES060), and RSS James Clark Ross (Cruise JR16004) for their efficient assistance. E. D. received funding from the project TOBACO (267660), POLARPROG, Norges Forskningsrd.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tamborski, J., Brown, C., Bokuniewicz, H., Cochran, J. K., & Rasbury, E. T. Investigating boron isotopes for identifying nitrogen sources supplied by submarine groundwater discharge to coastal waters. Frontiers in Environmental Science, 8, (2020): 126, doi:10.3389/fenvs.2020.00126.

Description: Stable isotopes of oxygen, nitrogen, and boron were used to identify the sources of nitrate (NO3–) in submarine groundwater discharge (SGD) into a large tidal estuary (Long Island Sound, NY, United States). Potential contaminants such as manure, septic waste and fertilizer overlap in δ15N and δ18O but have been shown to have distinctive δ11B in non-coastal settings. Two distinct subterranean estuaries were studied with different land-use up gradient, representative of (1) mixed medium-density residential housing and (2) agriculture. These sites have overlapping δ15N and δ18O measurements in NO3– and are unable to discriminate between different N sources. Boron isotopes and concentrations are measurably different between the two sites, with little overlap. The subterranean estuary impacted by mixed medium-density residential housing shows little correlation between δ11B and [B] or between δ11B and salinity, demonstrating that direct mixing relationships between fresh groundwater and seawater were unlikely to account for the variability. No two sources could adequately characterize the δ11B of this subterranean estuary. Groundwater N at this location should be derived from individual homeowner cesspools, although measured septic waste has much lower δ11B compared to the coastal groundwaters. This observation, with no trend in δ11B with [B] indicates multiple sources supply B to the coastal groundwaters. The agricultural subterranean estuary displayed a positive correlation between δ11B and [B] without any relationship with salinity. Binary mixing between sea spray and fertilizer can reasonably explain the distribution of B in the agricultural subterranean estuary. Results from this study demonstrate that δ11B can be used in combination with δ15N to trace sources of NO3– to the subterranean estuary if source endmember isotopic signatures are well-constrained, and if the influence of seawater on δ11B signatures can be minimized or easily quantified.

Description: This research was funded by New York Sea Grant projects R/CMC-13 and R/CMC-13-NYCT. The MC-ICP-MS used for this work was funded through NSF-MRI 0959524.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tamborski, J., Cochran, J. K., Bokuniewicz, H., Heilbrun, C., Garcia-Orellana, J., Rodellas, V., & Wilson, R. Radium mass balance sensitivity analysis for submarine groundwater discharge estimation in semi-enclosed basins: the case study of Long Island Sound. Frontiers in Environmental Science, 8, (2020): 108, doi:10.3389/fenvs.2020.00108.

Description: Estimation of submarine groundwater discharge (SGD) to semi-enclosed basins by Ra isotope mass balance is herein assessed. We evaluate 224Ra, 226Ra, and 228Ra distributions in surface and bottom waters of Long Island Sound (CT-NY, United States) collected during spring 2009 and summer 2010. Surface water and bottom water Ra activities display an apparent seasonality, with greater activities during the summer. Long-lived Ra isotope mass balances are highly sensitive to boundary fluxes (water flux and Ra activity). Variation (50%) in the 224Ra, 226Ra, and 228Ra offshore seawater activity results in a 63–74% change in the basin-wide 226Ra SGD flux and a 58–60% change in the 228Ra SGD flux, but only a 4–9% change in the 224Ra SGD flux. This highlights the need to accurately constrain long-lived Ra activities in the inflowing and outflowing water, as well as water fluxes across boundaries. Short-lived Ra isotope mass balances are sensitive to internal Ra fluxes, including desorption from resuspended particles and inputs from sediment diffusion and bioturbation. A 50% increase in the sediment diffusive flux of 224Ra, 226Ra, and 228Ra results in a ∼30% decrease in the 224Ra SGD flux, but only a ∼6–10% decrease in the 226Ra and 228Ra SGD flux. When boundary mixing is uncertain, 224Ra is the preferred tracer of SGD if sediment contributions are adequately constrained. When boundary mixing is well-constrained, 226Ra and 228Ra are the preferred tracers of SGD, as sediment contributions become less important. A three-dimensional numerical model is used to constrain boundary mixing in Long Island Sound (LIS), with mean SGD fluxes of 1.2 ± 0.9 × 1013 L y–1 during spring 2009 and 3.3 ± 0.7 × 1013 L y–1 during summer 2010. The SGD flux to LIS during summer 2010 was one order of magnitude greater than the freshwater inflow from the Connecticut River. The maximum marine SGD-driven N flux is 14 ± 11 × 108 mol N y–1 and rivals the N load of the Connecticut River.

Description: This project has been funded by New York Sea Grant projects (R/CCP-16 and R/CMC-12). This research is contributing to the ICTA-UAB Unit of Excellence “María de Maeztu” (MDM-2015-0552) and MERS (2017 SGR – 1588, Generalitat de Catalunya). VR acknowledges financial support from the Beatriu de Pinós postdoctoral program of the Catalan Government (2017-BP-00334).

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Steen, A. D., Kusch, S., Abdulla, H. A., Cakic, N., Coffinet, S., Dittmar, T., Fulton, J. M., Galy, V., Hinrichs, K., Ingalls, A. E., Koch, B. P., Kujawinski, E., Liu, Z., Osterholz, H., Rush, D., Seidel, M., Sepulveda, J., & Wakeham, S. G. Analytical and computational advances, opportunities, and challenges in marine organic biogeochemistry in an era of "Omics". Frontiers in Marine Science, 7, (2020): 718, doi:10.3389/fmars.2020.00718.

Description: Advances in sampling tools, analytical methods, and data handling capabilities have been fundamental to the growth of marine organic biogeochemistry over the past four decades. There has always been a strong feedback between analytical advances and scientific advances. However, whereas advances in analytical technology were often the driving force that made possible progress in elucidating the sources and fate of organic matter in the ocean in the first decades of marine organic biogeochemistry, today process-based scientific questions should drive analytical developments. Several paradigm shifts and challenges for the future are related to the intersection between analytical progress and scientific evolution. Untargeted “molecular headhunting” for its own sake is now being subsumed into process-driven targeted investigations that ask new questions and thus require new analytical capabilities. However, there are still major gaps in characterizing the chemical composition and biochemical behavior of macromolecules, as well as in generating reference standards for relevant types of organic matter. Field-based measurements are now routinely complemented by controlled laboratory experiments and in situ rate measurements of key biogeochemical processes. And finally, the multidisciplinary investigations that are becoming more common generate large and diverse datasets, requiring innovative computational tools to integrate often disparate data sets, including better global coverage and mapping. Here, we compile examples of developments in analytical methods that have enabled transformative scientific advances since 2004, and we project some challenges and opportunities in the near future. We believe that addressing these challenges and capitalizing on these opportunities will ensure continued progress in understanding the cycling of organic carbon in the ocean.

Description: The Hanse-Wissenschaftskolleg Delmenhorst, Germany, sponsored the “Marine Organic Biogeochemistry” workshop in April 2019, of which this working group report was a part. The workshop was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – project number: 422798570. The Geochemical Society provided additional funding for the conference. AS was supported by DOE grant DE-SC0020369.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bracco, A., Paris, C. B., Esbaugh, A. J., Frasier, K., Joye, S. B., Liu, G., Polzin, K. L., & Vaz, A. C. Transport, fate and impacts of the deep plume of petroleum hydrocarbons formed during the Macondo blowout. Frontiers in Marine Science, 7, (2020): 542147, doi:10.3389/fmars.2020.542147.

Description: The 2010 Macondo oil well blowout consisted in a localized, intense infusion of petroleum hydrocarbons to the deep waters of the Gulf of Mexico. A substantial amount of these hydrocarbons did not reach the ocean surface but remained confined at depth within subsurface plumes, the largest and deepest of which was found at ∼ 1000–1200 m of depth, along the continental slope (the deep plume). This review outlines the challenges the science community overcame since 2010, the discoveries and the remaining open questions in interpreting and predicting the distribution, fate and impact of the Macondo oil entrained in the deep plume. In the past 10 years, the scientific community supported by the Gulf of Mexico Research Initiative (GoMRI) and others, has achieved key milestones in observing, conceptualizing and understanding the physical oceanography of the Gulf of Mexico along its northern continental shelf and slope. Major progress has been made in modeling the transport, evolution and degradation of hydrocarbons. Here we review this new knowledge and modeling tools, how our understanding of the deep plume formation and evolution has evolved, and how research in the past decade may help preparing the scientific community in the event of a future spill in the Gulf or elsewhere. We also summarize briefly current knowledge of the plume fate – in terms of microbial degradation and geochemistry – and impacts on fish, deep corals and mammals. Finally, we discuss observational, theoretical, and modeling limitations that constrain our ability to predict the three-dimensional movement of waters in this basin and the fate and impacts of the hydrocarbons they may carry, and we discuss research priorities to overcome them.

Description: This review was made possible by funding from the Gulf of Mexico Research Initiative (GoMRI) and is a product of the Core Area 1 Synthesis workshop. The authors have contributed research on the Gulf deep circulation and the deep plume through GoMRI-funded consortia (ECOGIG for AB, SJ and GL, C-IMAGE for CP, AV and KF, and RECOVER for AE) and one of the RFP-5 grant (KP). KP was partially supported also by NSF OCE-1536779.