ALBERT

Description: The potential of shortwave infrared (SWIR) remote sensing to detect hotspots has been investigated using satellite data for decades. The hotspots detected by satellite SWIR sensors include very high-temperature heat sources such as wildfires, volcanoes, industrial activity, or open burning. This study proposes an automated classification method of heat source detected utilizing Landsat 8 and Sentinel-2 data. We created training data of heat sources via visual inspection of hotspots detected by Landsat 8. A scheme to classify heat sources for daytime data was developed by combining classification methods based on a Convolutional Neural Network (CNN) algorithm utilizing spatial features and a decision tree algorithm based on thematic land-cover information and our time series detection record. Validation work using 10,959 classification results corresponding to hotspots acquired from May 2017 to July 2019 indicated that the two classification results were in 79.7% agreement. For hotspots where the two classification schemes agreed, the classification was 97.9% accurate. Even when the results of the two classification schemes conflicted, either was correct in 73% of the samples. To improve the accuracy, the heat source category was re-allocated to the most probable category corresponding to the combination of the results from the two methods. Integrating the two approaches achieved an overall accuracy of 92.8%. In contrast, the overall accuracy for heat source classification during nighttime reached 79.3% because only the decision tree-based classification was applicable to limited available data. Comparison with the Visible Infrared Imaging Radiometer Suite (VIIRS) fire product revealed that, despite the limited data acquisition frequency of Landsat 8, regional tendencies in hotspot occurrence were qualitatively appropriate for an annual period on a global scale.

Description: Published

Description: 102491

Description: 7A. Geofisica per il monitoraggio ambientale

Description: JCR Journal

Description: We describe the diagnostic lithological and chemical features of distal tephras from major MiddleLate Pleistocene (560e36 ka) explosive eruptions of the Colli Albani volcanic district, central Italy. In particular, we explore the time-dependent variability of the Sr and Nd isotope compositions as a tool for recognising and pinpointing individual Colli Albani tephra in distal settings. The distal tephras investigated are in lacustrine and fluvial sediments of central Apennine intermountain basins located 70 kme100 km east of Colli Albani. The recognition of the Colli Albani tephras is essentially based on the K-foiditic composition of their glass, which, within the Italian volcanological framework, is a distinctive character of the Colli Albani pyroclasts. In detail, these tephras are attributed to the following eruptive units: Tufo Pisolitico di Trigoria (561 2 ka); Tufo del PalatinoeTufo di Bagni Albule (530 2/527 2 ka), Tufo di Bagni AlbuleePozzolane Rosse air-fall sequence (517 1 to 500 3 ka), Pozzolane Rosse (457 4 ka), Villa Senni (365 4 ka), and Albano 5e7 (41 7 to 36 1 ka). These correlations are supported by 40Ar/39Ar dating of the distal tephras correlated to the Pozzolane Rosse (457.4 1.7 ka), Villa Senni (365 2 ka) and Albano 5e7 (41 9 ka) and by 87Sr/86Sr measured on clinopyroxene crystals and fresh glassy scoria from distal Colli Albani tephras that range from w0.711 to w0.709. These ratios are similar to those that characterise the individual proximal correlative units, and show the same decreasing trend over time. In contrast, the 143Nd/144Nd ratios for proximal and distal bulk samples and clinopyroxene increase from w0.51212 to w0.51215 from the oldest to the youngest tephra deposit. In summary, the study of Sr and Nd isotope compositions that is here applied on products from the Colli Albani volcanic district is a powerful, complementary tool to the more traditional tephrostratigraphic methods (e.g., componentry and electron microprobe analysis) for fingerprinting of distal tephras over a large region of the central Mediterranean, and over a large time interval, such as from 560 ka to 36 ka.

Description: Published

Description: 190-206

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: JCR Journal

Description: Fluid migration along faults can be highly complex and spatially variable, with the potential for channeled flow, accumulation in capped porous units, fault cross-flow, lateral migration along strike, or complete sealing. Extensional basin margins can be important for such migration, given the associated crustal thinning and decompression that takes place combined with potential geothermal or mantle gas sources. One such example is near the urban area of Rome, situated along the active extensional continental margin of the Tyrrhenian back arc basin and surrounded by Middle-Upper Pleistocene K-rich and arc-related volcanoes. Recent research activities in the area around Fiumicino, a town 25 km to the west of Rome, has highlighted the close spatial link between degassing CO2 and the faults that provide the necessary vertical migration pathways. In particular, detailed soil gas and gas flux surveys have highlighted the release at surface of large volumes of asthenospheric mantle CO2 in correspondence with normal faults observed in a new seismic reflection profile acquired along the Tiber River. Detailed reconstruction of the Pleistocene–Holocene stratigraphy of the area dates fault activity from 20,000 to 9000 years BP. It is proposed that the gas migrates preferentially along the cataclastic tectonic breccias of the faults until it encounters recent, unconsolidated sediments; porous units within this shallow stratigraphy act as temporary secondary traps for the leaking gas, with local gas release at the ground surface occurring where the sealing of the overlying aquitards has been compromised. Degassing and active faults confirm the extensional tectonics affecting the area and the geodynamic scenario of a mantle wedge beneath the western Apennines, associated with ongoing W-directed subduction. Moreover, degassing highlights the potential geochemical and seismic risks for the highly populated urban areas near Rome.

Description: Published

Description: 137-149

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

Description: JCR Journal

Description: Time-series analyses of satellite images reveal that sea ice extent in the Ross Sea has experienced significant changes over the last 40 years, likely triggered by large-scale atmospheric anomalies. However, resolving how sea ice in the Ross Sea has changed over longer timeframes has until now remained more elusive. Here we used a laminated sediment piston core (14.6 m) collected from the Edisto inlet (Western Ross Sea) to reconstruct fast ice dynamics over the last 2.6 ka. Our goal was to first understand the climate expression of selected well-defined sediment laminae and then use these characteristics for reconstructing past sea ice behaviour across the whole sedimentary sequence. We used the recently established sea ice diatom biomarker proxy IPSO25 in combination with diatom census counts and bulk analyses. Analyses performed on a suite of discrete laminae revealed statistically significant differences between dark and light laminae reflecting different depositional conditions. Based on their respective biogeochemical fingerprints, we infer that dark laminae accumulated during sea ice thaws in early summer. Under these conditions, laminae contain relatively high concentrations of IPSO25 and display an enriched d13C composition for the bulk organic matter (OM). While diatom assemblages in dark laminae are relatively homogenous, as the thaw continues later in the summer, Corethron pennatum becomes the dominant diatom species, resulting in the formation of light laminae characterized by low IPSO25 concentrations. Since C. pennatum can migrate vertically through the water column to uptake nutrients and avoid competition in oligotrophic waters, its high concentration likely reflects stratified and ice-free surface waters typical of late summer. Down-core trends show that the correlation between sediment brightness and geochemical fingerprint (i.e., IPSO25 and d13C) holds throughout the record. Based on the knowledge gained at lamina level, our down-core high-resolution reconstruction shows that the summer fast ice coverage changed dramatically during the late Holocene. Specifically, we conclude that the Edisto inlet experienced regular early summer opening between 2.6 ka, and ca. 0.7 ka, after which, coastal fast ice persisted during summer months and ice-free conditions became less frequent. Comparison with previous regional ice core data suggests that the sudden cooling recorded over the Victoria Land Coast region since 0.7 ka might potentially explain our observation of persistent summer fast ice in the Western Ross Sea. Our study has shown that multi-proxy data derived from laminated sediments can provide hitherto unknown detail regarding past summer sea ice dynamics in coastal Antarctic regions.

Description: Published

Description: 106299

Description: 4A. Oceanografia e clima

Description: JCR Journal

Description: The fallout of ballistic blocks and bombs ejected from eruptive vents has the potential to produce severe injuries to people and damage to infrastructure in areas proximal to volcanoes. The dimensions and dispersions of ballistic ejecta from explosive eruptions are pivotal parameters to forecast the potential impact associated with future eruptions based on the compilation of probabilistic hazard maps. In this study, we propose a new probabilistic hazard quantification strategy to provide the probability of Volcanic Ballistic Projectiles (VBPs) to exceed some critical kinetic energy thresholds, considering a variability on the site of the eruptive vents and the effect of wind. La Soufrière de Guadeloupe (Lesser Antilles) is chosen as a test case, focussing on the most likely style explosive scenario associated with the eruption of an active lava dome (including phreatic, Vulcanian and Strombolian eruptions). Sensitivity analyses have guided the optimization of input parameters to balance the results stability and computational costs, showing that the topography is a pivotal factor when accounting for the spatial uncertainty on vent locations in the proximity of the dome area. Given an eruption within the adopted scenario, we provide maps showing the probability to exceed different energy reference thresholds for roof's perforation if at least one VBP falls in a target area. These maps are then combined with exposed elements to produce a qualitative exposure-based risk map. We compute the overall probability, conditional on the selected scenario, for roof perforation in a given area when a VBP is ejected. Results show probabilities varying from ca. 2% up to 40% within a few km from the volcano, quickly dropping away from the dome. However, when the probability to exceed the energy reference threshold is only conditional on falling of VBPs in a target area, most of Basse-Terre island would be affected by the 20–60% probability of roof perforation. This work confirms how the choice of a probabilistic approach is key to estimate the likelihood of occurrence of VBPs impacts as a first step towards the development and implementation of pro–active risk reduction strategies in volcanic areas.

Description: Published

Description: 107453

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

Description: JCR Journal

Description: Dst (Disturbance Storm Time) is an hourly index of magnetic activity computed from the measured intensity of the globally symmetrical equatorial electrojet (Ring Current) obtained by a series of near-equatorial geomagnetic observatories. We selected and trained an Artificial Neural Network (ANN) to give the estimation of the Dst index through the magnetic data measured by the Swarm three-satellite mission. From November 2014 to December 2019, we selected a balanced number of quiet and disturbed days, to get the most uniform set of Dst index values as possible. We then collected a big data collection of Swarm magnetic signals, confined to three very narrow belts of low-to-mid latitude: this choice allows it to better resemble the geographic distribution of the geomagnetic observatories contributing to the calculation of Dst. We also extended the analysis to mid latitude locations to increase the number of satellite samples. Once we determined by means of simulations the best network topology, we trained the network and tested its capabilities. The outcomes show that the ANN is able to give a reliable fast estimation of the Dst index directly from Swarm satellite magnetic data.

Description: Published

Description: 837-855

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: Available manually scaled foF2 observations over 50 years on Juliusruh, 33 years on Slough, and 37 years on Rome stations were used to check the association between quiet-time foF2 disturbances (Q-disturbances) and following on isolated magnetic storms. Of course, such cases exist, however Pearson's contingency coefficient, Chi-square and Odds ratio tests applied to check a measure of association gave the absence of relationship even at the 95% confidence level. The lack of association makes it impossible to use F2-layer disturbances as precursors for magnetic storms. The observed cases of apparent relationship between two events should be considered as random and physically unconditioned. The published cases indicating the relationship between two events can be explained in the framework of regular F2-layer variations not related by any means to the following on magnetic storms.

Description: Published

Description: 105473

Description: 2A. Fisica dell'alta atmosfera

Description: JCR Journal

Description: On-fault processes during earthquakes contribute to seismic rupture propagation and slip. Here we investigate clast fragmentation in an experimental pseudotachylyte (solidified seismic melt) produced with a rotary shear machine. We slid for 0.44 m (corresponding to Mw ≥ 6 earthquakes), at slip rates 〉 1 m/s, pre-cut samples of quartz + phyllosilicates + plagioclase + sillimanite + garnet -bearing ultramylonite, that hosts pseudotachylytes in nature. The ultramylonite minerals extensively preserved as clasts in the experimental pseudotachylyte are quartz, plagioclase, and sillimanite. Garnet is scarcely preserved, despite having a melting temperature similar to plagioclase, probably due to having low thermal shock resistance. This selective clast survival is identical to the one found in the natural pseudotachylytes. Based on these experimental observations and assuming non-equilibrium melting, the preservation of a mineral, as a clast, in the melt appears to be controlled by its thermal shock properties as well as by its melting temperature. Since the mechanical effects of rupture propagation in these experiments were negligible, we conclude that, for Mw ≥ 6 earthquakes, (i) frictional slip and heating of the slipping zone plus (ii) thermomechanical properties of minerals, rather than fault rupture processes, control mineral comminution and clast survival in frictional melts.

Description: This work was supported by: University of Padova BIRD175145/17 (G.P.), European Research Council CoG project 614750 NOFEAR (G.D.T. and E.S.), and NSERC Discovery Grant 2018–06023 (A.Cam.). The authors thank Leonardo Tauro (University of Padova) for thin section preparation. The authors acknowledge two anonymous reviewers and the Editor Fabrizio Agosta for their constructive comments.

Description: Published

Description: 104328

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: The magnitude and intensity of the 60 CE Cretaio Tephra, the largest historical explosive eruption at Ischia caldera (Italy), was studied integrating field data and numerical modelling in order to reconstruct the dispersal of the fall out related to the climax phase of the eruption and characterize its physical parameters. A field survey of the main fall unit (EUC) of Cretaio Tephra and its sampling was performed on the island, which is the proximal area of dispersal, and for the first time outcrops of this tephra were found southward on the Capri Island. The dataset is completed by a distal tephra sampled in the offshore and described in the literature, allowing the analysis of samples of intermediate and distal deposits. Grain size analysis of the samples collected on the island show bimodal distributions due to the presence of a ballistic component, especially in the most proximal sampling sites around the inferred and buried vent. Tails of fine ash in the distributions can be associ ated with settling enhanced by ash aggregation processes in the moisture-rich plume. Tephra dispersal was re constructed using the HAZMAP tephra dispersal model by minimizing the difference between the simulations obtained exploring plausible ranges of eruption source parameters and the available thickness and grain-size measurements. Results show that the dispersal axis of EUC is to the south-southeast, the best guess for the total erupted volume of tephra is 0.075 km3 , the plume height ranges between 5 and 13 km, for an average mass eruption rate (MER) of 105 kg/s, hence a duration of the eruption of a few days. Considering an eruptive sce nario given by the eruption parameters and diffusion coefficient of the Cretaio Tephra, together with a statistical set of wind profiles, HAZMAP modelling allowed us to generate tephra loading probability maps, needed to assess the impact of such an eruption at Ischia Island and the Neapolitan metropolitan area, pivotal for civil protection purposes. Another important outcome of the study is that, for volcanic islands, the reconstruction of eruption parameters may benefit much more from the search of even few medial and distal offshore outcrops than from implementing the on-island proximal dataset only.

Description: Published

Description: 107248

Description: 5V. Processi eruttivi e post-eruttivi

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

Description: JCR Journal

Description: Although several observations have been reported in the literature before a strong earthquake, their relation with the forthcoming event is often controversial. Since many physical processes and parameters govern the dynamics of preparation, initiation, and occurrence of earthquakes, their understanding is essential for explaining anomalous seismological, geophysical, hydrological and geodetic signals before a strong earthquake that may be considered for seismic monitoring and hazard assessment. In this work, the interseismic and coseismic stress and strain fields associated with the 6 April 2009, Mw 6.3 L’Aquila earthquake are calculated via a 3D numerical model designed to simulate the crustal interseismic loading and the coseismic brittle episodic dislocation along the fault. The model adopts a framework of gravitational and tectonic forces that are compatible with the geodynamics of the Central Apennines region of the Italian territory. The model assumes a brittle upper crust, where the fault has stick-slip behaviour, and a plastic deeper crust, where the fault is in stationary creep. The results indicate that the concurrent action of gravitational and tectonic forces determines steep inter- seismic stress gradients at the transition between the creeping and locked fault planes that promote the coseismic subsidence of the hanging wall. The interseismic strain above the transition between that locked upper fault and its unlocked lower shear zone develops a dilated volume in the hanging wall and a contracted volume in the footwall. These stress and strain variations are compatible with seismological, geophysical and geodetic anomalies observed before the earthquake, i.e., Vp/Vs anomalies and location of foreshocks. Interseismic stress and strain patterns invert during the coseismic stage. The dilated volume, formed during the interseismic phase, will be contracted at the coseismic stage and, conversely, the footwall volume previously contracted will be expanded.

Description: Published

Description: 228685

Description: 2T. Deformazione crostale attiva

Description: JCR Journal

Description: Study of a natural analogue for risk assessment. Experimental and numerical modelling approach was applied. Technique validation for measuring the flux of a CO2 single point emission site. We did an experimental and numerical modelling approach to prove methods and results.

Description: Carbon dioxide is an essential gas for life on earth although it can be lethal to living beings at high concentrations in the atmosphere. Episodic release of CO2 from underground can occur either from natural processes (i.e., mantle degassing, thermal decarbonation) or industrial (geological storage of CO2, CCS). CO2 is a colourless and odourless gas denser than air, and once released in the atmosphere from point sources, its dynamics is initially governed by buoyancy and a gas cloud can accumulate above the ground (gravitational phase) leading to the formation of the so-called “CO2 lakes”. With time, CO2 distribution is then governed by wind and atmospheric turbulence (passive dispersion phase). Natural analogues provide evidences of the impact of CO2 leakage on vegetal cover, wild life and human beings. In this work, the dynamics of CO2 in the atmosphere after ground emission is assessed to quantify their potential risk. Two approaches have been followed: (1) direct measurement of air concentration in a natural emission site, where formation of a “CO2 lake” is common and (2) numerical atmospheric modelling with the TWODEE code. The studied site is located in the Campo de Calatrava region in central Spain, which is known for a widespread degassing of mantle-derived CO2. This site, called Cañada Real, has a degassing rate between 1 and 3 tonnes of CO2 per day. When atmospheric conditions are quite stable, i.e., negligible wind speed, the formation of a blanket of CO2-enriched air is visible at naked eye reaching up to 50 cm high. The CO2 concentration measured in air is typically higher than 10,000 ppm in most monitoring stations. The measured data are consistent with the numerical models that predict maximum concentration between 40,000 and 70,000 ppm CO2 in air, which is by far higher than the 30,000 ppm threshold from which hazardous effects on human beings are observed. Conclusions from this work, however, indicate that the risk for humans even at large emission rates is low due to the CO2 dispersion effect into the atmosphere, and only under very particular conditions lethal effects are predicted.

Description: Published

Description: 38-47

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

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

Description: JCR Journal

Description: The volcanic activity that built up the Monte dei Porri stratocone (Salina Island) was reconstructed using new stratigraphic data, which allowed seven eruption units to be distinguished. Alternating Strombolian/Vulcanian to sub-Plinian/Plinian explosive and effusive activity emplaced fall and pyroclastic density current deposits and lava flows that formed the volcanic cone. The minimum erupted bulk volumes were assessed at 100 × 10 6 m 3 each for EU1, EU2, EU3 and EU6, while that of EU4 is ca. 200 × 10 6 m 3 . Rough estimation of EU7 volume yields values around 150 × 10 6 m 3 . The calculation of volume was not possible for the EU5 deposits. The magmas that fed the different eruption units of the Monte dei Porri succession range in composition from basalt to andesite, with the exception of dacites erupted in the initial phase of activity. SEM image analyses on coarse ash from the different pyroclastic units suggest that hydromagmatic fragmentation cannot be the cause of the large variations in explosivity observed throughout the stratigraphic succession. Based on the lithic component of pyroclastic deposits and xenolith contents of lava flows, the plumbing system that fed the different eruption units of Monte dei Porri was split into a deep magma storage level (15–20 km) and shallower magma batches (3–5 km). Our calculations indicate that the volumes of erupted material can account for magmatic triggering (injection of new magma) of eruptive units from the shallower feeding system, but they are not sufficient for suggesting magmatic initiation of the eruption units from the deeper feeding system. It is therefore assumed that the eruptions from the deep magma reservoir necessitate a favourable lithostatic stress, likely calling for a reduction of the local tectonic forces. A qualitative model explaining the eruptive style transitions among and within the different eruption units is presented, taking into account the relation between magmatic overpressure and lithostatic stress.

Description: Published

Description: 1-22

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal

Description: Thermal activity is a common precursor to explosive volcanic activity. The ability to use these thermal precursors to monitor the volcano and obtain early warning about upcoming activity is beneficial for both human safety and infrastructure security. By using a very reliably active volcano, Stromboli Volcano in Italy, a method has been developed and tested to look at changes in the frequency of small scale explosive activity and how this activity changes prior to larger, ash producing explosive events. Thermal camera footage was used to designate parameters for typical explosions at Stromboli (size of spatter field, cooling rate, frequency of explosions) and this information was applied to characterize explosions in satellite imagery. Satellite data from The National Aeronautics and Space Administration's Moderate Resolution Imaging Spectroradiometer (MODIS) and US/Japan designed Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) for numerous periods in 2002 to 2009 were analyzed for thermal features which were used to calculate an estimate of the level of activity during the given time period. The results at Stromboli showed a high level of small scale explosions which stop completely prior to large paroxysmal eruptive episodes. This activity also corresponds well to seismic and infrasonic records at Stromboli, indicating that this thermal infrared monitoring method may be used in conjunction with other detection methods where available, and also indicates that it may be a useful method for volcano monitoring when other methods (e.g. seismic instrumentation, infrasound arrays, etc.) are not available.

Description: Published

Description: 159-171

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal

Description: The resuspension of volcanic ash by wind is a significant source of hazard during and after volcanic eruptions. Parameterizing and modeling ash resuspension requires direct measurement of the minimum wind shear stress required to move particles, usually expressed as the threshold friction velocity U*th, a parameter that, for volcanic ash, has been measured only scarcely and always in the laboratory. Here, we report the first field measurements of U*th for volcanic ash, with a portable wind tunnel specifically developed, calibrated, and tested. Field measurements, performed on natural reworked ash deposits from Sakurajima (Japan) and Cordón Caulle (Chile) volcanoes, agree well with our laboratory determinations on ash from the same deposits, with values of U*th ranging from 0.13 to 0.38 m/s. Our results show that the median grain size of the deposit and particle shape have a stronger control on U*th than the local substratum nature and deposit texture.

Description: Published

Description: 116684

Description: 5V. Processi eruttivi e post-eruttivi

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

Description: JCR Journal

Description: Fluids play an important role in seismic faulting both at hypocentral depths during earthquake nucleation and at shallower crustal levels during rupture propagation. Pre- to co-seismic anomalies of crustal fluid circulation have been identified by hydrogeochemical and seismological monitoring and interpreted as potential precursors of strong earthquakes. To shed light on the role of fluids in seismic and precursory mechanisms, the active carbonate-hosted principal slip zone (7-8 cm thick) of the exhumed (exhumation 〈 3 km) normal Mt. Morrone Fault (central Apennines) has been investigated with a multi-disciplinary approach from the macro- to the nano-scale. The distal slip zone consists of white cementitious calcite-rich bands and red cataclastic bands composed of dolomite and calcite clasts embedded in a clay-rich matrix. The proximal slip zone consists of subparallel ultracataclastic layers separated by sharp slip surfaces. The ultracataclastic layers mutually inject/overprint, bearing evidence of granular fluidization, dolomite thermal decomposition, and clay amorphization. Fluid inclusions and the distribution of both trace and major elements reveal the inflow of both shallow and deep external fluids into the slip zone. Presumably, the deep fluids originated from a magmatic-like source and ascended along the fault during pre-seismic dilation and seismic ruptures, interacting with shallow phyllosilicate-rich flysch deposits and the fluids hosted within them. In this context, vanadium-rich fluidized microlayers along the exhumed Mt. Morrone Fault are reminiscent of vanadium-rich potential hydrogeochemical precursors arose in the shallow aquifers of the study area since a few months before the 2016 Mw 6.0 Amatrice earthquake.

Description: Published

Description: 117010

Description: 7T. Variazioni delle caratteristiche crostali e "precursori"

Description: JCR Journal

Description: In order to elucidate the kinetic partitioning of cations between olivine and basalt, we performed undercooling (−ΔT) and cooling rate (CR) experiments at atmospheric pressure and QFM-2 buffer. Starting from the superliquidus temperature of 1250 °C, a Hawaiian tholeiitic basalt was cooled at the rates of 4 (CR4), 20 (CR20), and 60 (CR60) °C/h to the final target temperatures of 1175 °C (−ΔT = 35 °C; −ΔT35) and 1125 °C (−ΔT = 85 °C; −ΔT85). Results show that polyhedral olivine morphologies are obtained at -ΔT35, whereas strong disequilibrium skeletal and/or dendritic textures form at -ΔT85. The amount of forsterite in olivine decreases from to 85% to 78% with increasing both -ΔT and CR. A diffusive boundary layer also develops in the melt next to the olivine surface and its composition becomes progressively enriched in Ca, owing to its incompatible behavior with the lattice site. Residual melts are progressively depleted in silica and enriched in alkali from CR4 to CR60, but silica-rich melts are observed with increasing -ΔT. In terms of Fe2+-Mg exchange, olivines obtained at -ΔT35 are always in equilibrium with the diffusive boundary layer, comprising both the interface melt next to the olivine surface and the far-field melt where all chemical gradients cease. At -ΔT85, however, the Fe2+-Mg exchange indicates two distinct equilibration stages between olivine core and far-field melt, and between olivine rim and interface melt. Partition coefficients (Kd) of Mg, Fe, Mn, Ca, and Cr calculated at the olivine-melt interface preferentially change as a function of -ΔT rather than CR. From -ΔT35 to -ΔT85, KdMg, KdFe, KdMn, and KdCr remarkably increase, whereas the opposite applies to KdCa. Through the application of equilibrium partitioning models, we found that Mg, Fe, Mn, and Ca are incorporated into the olivine lattice site at near-equilibrium proportions. This generally good agreement with modeling data demonstrates that diffusive mass transport of cations in our experiments occurred under the conditions of local equilibrium at the olivine surface. In contrast, marked deviations from the expected equilibrium are found for KCr in response to the major influence of crystal field stabilization energy on cation incorporation.

Description: Published

Description: 120485

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

Description: JCR Journal

Description: This investigation uses simultaneous observations from all-sky imager system and an ionosonde collocated at Araguatins (5.65° S, 48.07° W and dip-latitude of 4.1° S), a near-equatorial region in Brazil. These simultaneous observations were used to investigate the occurrence of plasma bubbles and blobs in the field of the imaging system and their association with atypical range Spread-F signature in ionograms. Also, in-situ observation of plasma density from Swarm satellites were used to support the ground-based observations. Using a few cases, a methodology will be established to identify in the plasma blobs (atypical ESF) in the ionograms when there is the simultaneous observation of plasma bubbles and blobs in the field of view of the ionosonde. For this purpose, simultaneous sequence of OI 630.0 nm nightglow images and ionograms are presented for different case studies; 1. when there is the absence of a plasma bubble or blob, 2. when there is only the occurrence of plasma bubbles and 3. when there is the occurrence of plasma bubbles and blobs, in order to compare traces in the ionogram in all these case studies. With these we can cover all kinds of signatures in the ionograms corresponding to no irregularities, plasma bubbles only and plasma bubbles-blobs. These OI 630.0 nm nightglow and ionograms recorded simultaneously make it possible to establish a novel methodology to recognize in ionograms cases when there is the occurrence of Spread-F signature associated with bubble-blob in the FOV of the ionosonde.

Description: Published

Description: 2416-2438

Description: 2A. Fisica dell'alta atmosfera

Description: JCR Journal

Description: Major, minor and trace element concentrations of single rainfall events were investigated at Masaya volcano (Nicaragua) in order to determine the relative contributions of volcanogenic elements. Most of the samples were collected in the summit area of the volcano around the Santiago crater, and two samples, representative of the local background, were collected at a 4.3 km upwind site. Samples from the summit are very acidic with pH down to 2.14 and contain large amounts of volcanogenic elements that can be clearly distinguished from the local background. These elements are released into the atmosphere from the continuously degassing lava lake of the Santiago crater, Masaya volcano. The emissions result in a volcanic plume that includes solid particles, acidic droplets, and gaseous species. The plume-rain interaction imprints the chemical signature of the volcanic emissions in falling raindrops. The most acidic gases (e.g. HCl and HI) readily dissolve in water, and so their ratio in rain samples reflects that of the volcanic plume. The transport of HF is mediated by the large amount of silicate particles generated at the lava–air interface. SO2 is only partially converted into H2SO4 that dissolves in water. The refractory elements dissolved in rain samples derive from the dissolution of silicate particles, and most of them (Al, Mg, Ca, Fe, Be, Ti, Mn, and Sr) are present at exactly the same molar ratios as in the rocks as well as rare earth elements (REEs). By contrast, Li, Na, K, Cr, Ni, Cu, Zn, Rb, Cd, Sb, Te, Cs, Tl, Pb, and Bi are enriched relative to the whole-rock composition, suggesting that they are volatilized during magma degassing. After correcting for the dissolution of silicate particles, we can define the relative volatility of these elements. The comparison with other volcanoes on the Pb emissions highlights the effect of oxygen fugacity in determining its volatility.

Description: Published

Description: 120562

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal

Description: We analyzed dispersion of intermediate and long period surface waves, recorded at permanent observatories in the Antarctic region, in a tomographic study based on group velocity. We considered Rayleigh waves from available records of all events which occurred during years 1991-1995, with latitude lower than 40°S and magnitude M≥5.0. We performed classic single-station dispersion analysis on the surface wave train to measure group velocity of the Rayleigh fundamental mode in the period range between 30 and 120 s. We iteratively applied two different techniques of filter analysis: a multiple-filter [Dziewonski et al., 1969] and a phase-matched filter algorithm [Herrin, and Goforth, 1977]. We used such dispersion measurements to compute two-dimensional maps of velocity anomalies in the region. We parameterized group velocity with linear splines, and inverted the linear system by means of singular value decomposition. Results are in significant agreement with earlier studies, but reach a considerably higher detail. Our model differentiates well among geologically different regions, such as the old East Antarctica craton, the accreted terranes of West Antarctica, and the oceanic lithosphere surrounded by the ring of mid-ocean ridges. We image slow areas corresponding to hot-spot regions, including a broad anomaly corresponding to recent volcanism in the Ross Sea, where the existence of a mantle plume has been proposed.

Description: Published

Description: 55-66

Description: 1T. Struttura della Terra

Description: JCR Journal

Description: Increased attention has been given to particulate matter (PM) that, as well as worsening air quality, is responsible for chronic and acute respiratory or cardiovascular diseases. Currently, most of the studies are focused on the capacity of plants and other biological media to adsorb PM, whereas few works explore the functional damage due to PM on urban vegetation. The present study, considering Quercus ilex L. as target species for its wide distribution in the Mediterranean urban and natural areas, pointed out that PM accumulation, inferred from magnetic and chemical properties, has almost no effects on structural morpho-functional traits as Relative Water Content or Specific Leaf Area but can impair processes related to the first photochemical reactions suggesting shading effect on leaves. PSI functionality and thus, carbon assimilation related processes, are impaired to a lesser extent by the oxidative potential of PM. Our results showed that, although several oxidative stressors can simultaneously affect morpho-functional traits, the interdisciplinary approach tested here can be a key tool to enlarge the spatial scale of biomonitoring activities as much as possible, and highlight a functional indicator of PM injury. This is needed to enhance the knowledge about the complex processes that are implied in the dynamic relationship between air quality, vegetation functionality and ecosystem services provisioning in urban areas.

Description: Published

Description: 107707

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: Pino et al. (2021, hereinafter PIN2021) commented on the paper by Barreca et al. (2021, hereinafter B2021) titled: “The Strait of Messina: Seismotectonics and the source of the 1908 earthquake”, which was published in the journal Earth-Sciences Reviews in May 2021. PIN2021 argued both on the “source model of the 1908 EQ”, as proposed by B2021, and on the existence of the newly discovered causative fault (i.e. the B2021W-Fault). Based on “objective reading of achieved results along with other existing geophysical information…“, PIN2021 conclude: “the source mechanism for the 1908 EQ is based on incorrect assumptions, while their results are internally inconsistent and with other independent observations”. According to PIN2021, the inconsistency of the proposed “source mechanism”, which foresaw the possibility of an aseismic slip on a low-angle discontinuity preceding the 1908 mainshock (see B2021), would be mainly demonstrated by “the lack of significant variations of the relative sea level in the Messina harbor area, in the time period relevant for the levelling data (1907-1908) ……. and at least for the decade preceding the event”. Moreover, to demonstrate that the deformation is mostly coseismic, PIN2021 proposes a sea level diagram based on unreliable data from the Messina tide gauge. In this paper, we demonstrate that the comments by PIN2021 are unfounded. We strongly confirm the scientific validity of the model proposed in B2021.

Description: Published

Description: 103866

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: In the recent decades, satellite monitoring techniques have enhanced the discovery of non-catastrophic slope movements triggered by earthquake shaking involving old paleo-landslides with deep-seated sliding surfaces. Understanding the triggering and attenuation mechanisms of such mass movements is crucial to assessing their hazard. In December 2018, Etna volcano (southern Italy) began a very intense eruption, which was accompanied by a seismic swarm with magnitudes reaching 4.9. Synthetic aperture radar data identified local displacements over a hilly area to the west of Paternò village. We evaluated the contribution of seismically induced surface instability to the observed ground displacement by employing a multidisciplinary analysis comprising geological, geotechnical and geomorphological data, together with analytical and dynamic modelling. The results allowed us to identify the geometry and kinematics of a previously unknown paleo-landslide, which was stable before the volcanic eruption. The landslide was triggered by the light-to-moderate seismic shaking produced by the strongest event of the seismic sequence, namely, the December 26, Mw 4.9 earthquake. This observation confirms that seismic shaking has a cumulative effect on landslides that does not necessarily manifest as a failure but could evolve into a catastrophic collapse after several earthquakes.

Description: Published

Description: 112524

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

Description: JCR Journal

Description: The small Plio-Quaternary volcanic centre of Cabezo Negro de Tallante in SE Spain includes a thick deposit of polymictic pyroclastic tuff-breccia, whose fragments are agglutinated by a carbonate-rich component. This feature is also observed in other monogenetic volcanic centres cropping out in the Tallante-Cartagena volcanic district. The carbonate fraction has been recently interpreted in literature as representing a mantle component, therefore pointing to the existence of a diffuse carbonatitic activity in the area. Based on detailed sedimentological (presence of pisoids and root remnants), petrographic (presence of plagioclase and absence of euhedral silicate minerals in the calcite plagues), mineral chemistry (Ba-Sr-poor calcite composition), whole-rock chemistry (overall low incompatible element content in the pure carbonate fraction and a monotonous trace element negative correlation with CaO) as well as isotopic constraints (perfect correlations between Sr-Nd-Pb isotopic ratios with CaO in the basaltic and carbonate fraction, as well as heavy δ18O and light δ13C isotopic composition of the carbonate fraction), we propose a secondary origin for the carbonate component, excluding any contribution of mantle carbonatite melts. The presence of carbonates infiltrating the abundant mantle and crustal xenolith fragments found in the pyroclastic breccia is not related to the presence of carbonatitic melts at mantle to lower crustal depths, but to in-situ fragmentation of the Strombolian tuffbreccia deposit, followed by secondary carbonate infiltration. The pyroclastic breccia was indeed affected by an alternation of carbonate precipitation and dissolution in a vadose zone, where the activity of bacteria, fungi, roots and meteoric water led to the formation of a calcrete (caliche)-type deposits. Basaltic rocks (hawaiites and basanites) occur in the area as scoria and lava fragments in the pyroclastic breccia as well as small lava flows. They have been modelled with a low-degree partial melting of an amphibole-bearing peridotitic mantle close to the lithosphere-asthenosphere boundary. The origin of the mildly alkaline sodic basaltic activity in SE Spain post-dates the abundant and long-lasting subduction-related volcanic phase in the Betic Chain. Its origin is explained without requiring the presence of any thermal anomaly, but simply as consequence of the difference of lithospheric depths and edge-driven-type small-scale convection

Description: Published

Description: 106140

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal

Description: We discuss the new causative source model for the 1908 Messina Straits earthquake recently proposed by Barreca et al. (2021), where an aseismic slip of 1.13 m along a low-angle discontinuity, preceding the 1908 earthquake, have mechanically destabilized a set of overlying faults, therefore leading them to the rupture. The lack of signi cant variations of the relative sea level in the Messina harbor area, in the time period relevant for the levelling data (1907–1908) analyzed by Barreca et al., and at least for the decade preceding the event proves the inconsistency of the assumed pre-earthquake aseismic slip. A careful interpretation of crustal earthquake dis- tribution in the Strait does not support the presence of the low-angle discontinuity. The modelled horizontal coseismic pattern reveals a scenario that is not supported by any other independent geological and geophysical observation. We conclude that the source model proposed by Barreca et al. for the 1908 Messina Straits earth- quake can not be considered as a viable hypothesis for the causative fault.

Description: Published

Description: 103865

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: Here we discussed the results of the first geochemical investigation of the fluids (groundwater and the associated gases) emerging in the southwest of Yazd Province. We carried out two surveys, one in July 2019 and the second in September 2019s, in the region of the Gariz aquifer (central Iran).Wefocused our attention to 1) the chemistry of thewater (major and minor constituents coupled to the stable isotopes of oxygen and hydrogen), 2) the chemical composition of dissolved gases in water together with 3) the isotopic composition of Helium (3He/4He) and 4) the dissolved carbon in water (δ13CTDIC). Hydrogen and oxygen isotope values of groundwater display a fairly narrow range and indicate that the waters are of meteoric origin. On the base of the major ions chemistry, the bulk of the water samples are classified as Ca-HCO3, Ca\\Cl and Na\\Cl types. The groundwater chemistry is mainly influenced by the interaction with CO2-rich fluids, leakage of chlorinated saline water into the alluvial aquifer, and silicate dissolution. High dissolved carbon contents, mainly as bicarbonate ion, reflect the noticeable interaction of the groundwater with CO2-rich fluids. CO2 is the dominant gaseous component in most samples and its amount is always greater with respect to a water in equilibrium with the atmosphere (Air Saturated Water, ASW). Such excess of CO2 contents (more than 730 cc/l STP) dissolved in groundwater also supports the presence of a deep source of CO2-rich gas. The computed δ13C(CO2) in equilibriumwith the groundwater highlight a mixing in different proportion between an inorganic deep sourced CO2 (13C-enriched) and organic CO2 (13C-depleted). We also used the helium isotopes as a tools to figure out the origin of helium in the aquifer (air vs. mantle, and crust). The collected samples show a contribution of mantle-derived He in the Gariz aquifer up to (~45%) and the crust suggesting that at regional scale the tectonic discontinuities had a connectionwith the mantle or magmatic intrusions migrated through the crust transporting mantle volatiles to shallowcrustal layers. However, we cannot infer the timing of this possible magmatism at depth in the complex tectonic evolution of the area.

Description: Ministry of Science, Research and Technology of Iran

Description: Published

Description: 107324

Description: 1TR. Georisorse

Description: JCR Journal

Description: Rome Capital City is located in a high heat flux area of central Italy, suitable for low-enthalpy geothermal exploitation. In the central-northern part of the city, near Tor di Quinto hippodrome close to Tiber River, a wide undeveloped area occurs, which is a possible future urban development site. We present the results of a geochemical and geophysical study aimed at assessing the presence in this zone of a low-enthalpy geothermal aquifer and at evaluating its depth, thickness and the physico-chemical characteristics of the geothermal water. Furthermore the natural CO2 output of this zone has been investigated. A soil CO2 flux survey with 551 measurements over a surface of 3.09 km2 revealed the presence of parallel NW-SE trending positive flux anomalies. The total CO2 output was estimated to 87.77 t*day-1, most of which (85 %) of endogenous or mixed origin. An Electrical Resistivity Tomography survey, consisting of five parallel 355 m long and 100 m spaced profiles, allowed the reconstruction of the stratigraphy of the underground sediments, which are fluvial deposits of the near Tiber River. The geothermal water is hosted in a low-resistivity layer, corresponding to the Tiber base gravels, which are here 20 m thick and whose top is 40 m below the surface. The water has a nearly constant temperature of 17.5 °C, a relatively high salinity and an appreciable content in dissolved gas. This low-enthalpy resource is suitable for direct uses, e.g. individual and district heating/cooling, sanitary hot water, spa facilities for swimming and bathing.

Description: This work was partially supported by the INGV AMUSED research project (CUP D59C19000100005)

Description: Published

Description: 102298

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

Description: JCR Journal

Description: The presence of water in volcano craters implies a higher susceptibility to specific, potentially hazardous volcanic events, such as phreatic and phreatomagmatic eruptions, lahars and limnic gas bursts. The driving process behind these hazards is magmatic degassing, inhibited to be released freely to the atmosphere due to a variable degree of physical and chemical decelerating capacity of the lake itself (e.g. selective scrubbing of gases, condensation of vapor, CO2 storage due to hydrostatic loading, bubble absorption along gas rise). This review chapter (1) presents new ideas on hazardous events related to volcanic lakes, (2) presents a revised comprehensive classification scheme, (3) shows how volcanic lakes are perceived by the local populations and cultures (risk perception), (4) revises and proposes mitigation strategies, (5) provides tips on how to ideally interpret precursory signals of such events in a suited, multi-disciplinary monitoring setup, and (6) can become a road map for future volcanic lake research, by posing unanswered questions and proposing working hypotheses.

Description: Published

Description: 439-471

Description: 4V. Processi pre-eruttivi

Description: Here we document how the different growth features and intracrystalline distributions of both major and trace cations in clinopyroxene phenocrysts are important recorders of the intricate magma dynamics at Vulcano Island (Aeolian Arc, Italy). The compositions of clinopyroxene phenocrysts from products erupted over the last ~54 ka cluster at different degrees of evolution, paralleling the polybaric-polythermal differentiation of mantle-derived mafic magmas into more evolved silicic melts. The hotter lower crust is the most favorable location for the storage of mafic magmas and the early crystallization of diopsidic (Mg#91) clinopyroxene (Pmax ≈ 750 MPa and Tmax ≈ 1220 °C). Diopsidic phenocrysts are depleted in both rare earth elements (REE) and high field strength elements (HFSE) but are enriched in transition elements (TE). The transfer and accumulation of primitive magmas in the colder upper crustal regions lead to the formation of an interconnected series of more differentiated magmatic reservoirs (P ≈ 100–450 MPa and T ≈ 1100–1180 °C) hosting discrete populations of clinopyroxene (Mg#84–85) with a broad spectrum of zonations and dissolution features. Recharge bands in clinopyroxene are markers of multiple inputs of primitive REE-HFSE-poor, TE-rich magmas from depth. Augitic phenocrysts (Mg#82) with strong negative Eu anomaly and REE + HFSE enrichments crystallizes from highly differentiated trachytic and rhyolitic melts stored at very shallow crustal conditions (P ≤ 50 MPa and T ≤ 1100 °C). These silicic reservoirs represent residual melts trapped-extracted from crystal-dominated mush regions in the uppermost part of the plumbing system. The residence time of clinopyroxene increases from ∼0.1 to ∼44 years from basalt to rhyolite, together with an increasing number of recharge bands. The mineral assemblage in more silicic and viscous mush melts is sufficiently resilient to record numerous mafic injections and high degrees of magma mixing, hybridization, and crystallization before eruption. Overall, the compositional zoning pattern of clinopyroxene presents a picture of plumbing system that extends through the crust and is characterized by distributions of melts and crystals which are progressively more evolved and heterogeneous in both space and time.

Description: Published

Description: 106517

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

Description: JCR Journal

Description: This paper is concerned with modeling earthquake-induced ground accelerations and the simulation of the dynamic response of linear structures through the principles of stochastic dynamics. A fully evolutionary approach, with nonstationarity both in amplitude and in frequency content, is proposed in order to define the seismic action, based on seismological information in the form of a small number of input parameters commonly available in deterministic or probabilistic seismic design situations. The signal is obtained by filtering a Gaussian white-noise. The finite duration and time-varying amplitude properties are obtained by using a suitable envelope function. By utilizing a subset of the records from the PEER-NGA strong-motion database, and time-series analysis tools extended to nonstationary processes, the key transfer-function properties, in terms of circular frequency, damping ratio and spectral intensity factor, are identified. A regression analysis is conducted for practical and flexible application of this model, in order to empirically relate the identified time-varying parameters of the filter to the characteristics defining earthquake scenarios such as magnitude, rupture distance and soil type. A validation study and a parametric investigation using elastic response spectra is also included. Results show that the final seismic model can reproduce, with satisfactory accuracy, the characteristics of acceleration records in a region, over a broad range of response periods.

Description: Published

Description: 1465-1479

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

Description: JCR Journal

Description: The determination of Eruptive Source Parameters (ESPs) is a major challenge especially for weak volcanic explosions associated with poorly exposed tephra-fallout deposits. In such a case, the combination of deposit analyses and remote sensing observations can provide fundamental insights. We use the 29 August 2011 weak paroxysm at Mount Etna (Italy) as a case study to discuss some of the challenges associated with multi-disciplinary determination of ESPs of poorly exposed tephra-fallout deposits. First, we have determined the erupted mass from a combination of field and synthetic data to fill a significant gap in data sampling; synthetic data have been derived based on extrapolation of field observations and validated based on comparisons with other tephra deposits at Etna and TEPHRA2 modelling. Second, we have combined the estimates of erupted mass and grain-size distribution as derived both from deposit observations and satellite retrievals. Analytical modelling was applied to characterize the size fractions most likely represented in satellite retrievals and tephra deposits, respectively. In addition, the Rosin-Rammler distribution fitting is shown to inform on missing parts of the grain-size distributions and reproduce a tail of very fine ash (1–20 μm) whose mass proportion is close to the satellite estimates (1.3–1.6% versus 1.9%, respectively). Finally, it was found that this very-fine-ash fraction increases as a function of satellite-derived Mass Eruption Rate for a set of eruptions for which independent estimates are available. This critical combination of field observations, analytical modelling and satellite retrievals demonstrates the potential and importance of multidisciplinary strategies for the derivation of ESPs even for small-size explosive events and poorly exposed deposits such as that of the 29 August 2011 paroxysm of Mt. Etna.

Description: Published

Description: 107431

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

Description: JCR Journal

Description: We performed a suite of experiments aimed at examining the frictional properties of unaltered basalts at conditions considered to be representative of slip at shallow depths in volcano-tectonic environments and in-situ geo-energy basaltic sites. Scientific drilling and field studies on exhumed subsurface faults and fractures analogues suggest that, frictional sliding in basalts can occur in shear zones within a volume of wear debris or along localized joint surfaces. To illuminate how microstructural heterogeneities affect the nucleation of slip instabilities in basalts, we sheared simulated fault gouge and bare rock surfaces at low normal stresses (4–30 MPa) at ambient temperature, under room-dry and wet conditions. We performed velocity steps (0.1–300 μm/s) and slide-hold-slides (30–3000 s holds) to determine the frictional stability and healing properties of basalts. In all the tests, we observed high friction coefficient associated with important frictional restrengthening. Overall, our results show that microstructural heterogeneities strongly affect the friction velocity dependence of basalts: while for normal stresses ≥10 MPa, shear localization accompanied by cataclasis and grain size reduction favors the transition to velocity weakening behavior of powdered samples, on bare surfaces gouge production during shearing promotes a transition to a velocity strengthening behavior. Our results imply that at the tested conditions, friction instabilities may promptly nucleate in shear zones where deformation within (unaltered) basaltic gouge layers is localized, such as those located along volcanic flanks, while joint surfaces characterized by rough rock-on-rock contacts are less prone to unstable slip, which is suppressed at velocities ≥10 μm/s.

Description: This work has benefited from the European Research Council project 614705 NOFEAR and Progetti di Ateneo La Sapienza Collettini 2018 grants. We are grateful to F.lli LIZZIO S.r.l. for providing Etnean basalt samples. We acknowledge D. “Mimmo” Mannetta, L. Tauro, and E. Masiero for thin section preparations and sample saw-cut, F. Zorzi for XRF and XRPD analyses, M. Nazzari for providing assistance with the SEM, and S. Mollo and E. Del Bello for technical support for the use of the He-pycnometer and the Separation Analyzer LUMiReader. We thank C. Marone for the XLook program for obtaining RSF parameters. CWA Harbord and S. Aretusini are acknowledged for technical support in the HP-HT laboratory and during SHIVA experiments. Telemaco Tesei is thanked for insightful discussion regarding this study. Carolina Giorgetti is thanked for her precious and constructive comments that helped to improve the quality of this study.

Description: Published

Description: 228883

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: The University of Bari (Italy), in cooperation with the National Institute of Geophysics and Volcanology (INGV) (Italy), has installed the OTRIONS micro-earthquake network to better understand the active tectonics of the Gargano promontory (Southern Italy). The OTRIONS network operates since 2013 and consists of 12 short period, 3 components, seismic stations located in the Apulian territory (Southern Italy). This data article releases the waveform database collected from 2013 to 2018 and describes the characteristics of the local network in the current configuration. At the end of 2018, we implemented a cloud infrastructure to make more robust the acquisition and storage system of the network through a collaboration with the RECAS-Bari computing centre of the University of Bari (Italy) and of the National Institute of Nuclear Physics (Italy). Thanks to this implementation, waveforms recorded after the beginning of 2019 and the station metadata are accessible through the European Integrated Data Archive (EIDA, https://www.orfeus-eu.org/data/eida/nodes/INGV/).

Description: Published

Description: 106783

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

Description: JCR Journal

Description: In 2016–2017, a destructive sequence of earthquakes affected a wide portion of Central Italy, activating a complex, 80-km long system of SW-dipping normal faults and causing impressive surface faulting and widespread damage. Former studies providing reconstructions of the fault systems activated during this sequence, are mostly based on high-resolution seismological and geodetic data. In this paper, we integrate surface and subsurface geological data with the ones obtained by an irregular network of seismic reflection profiles, aimed at providing a comprehensive reconstruction of the subsurface lithologies and structures in this area. We have constructed a set of five geological cross-sections, passing through the mainshock epicentral areas (Mw 〉 5.5) of the seismic sequence. The cross-sections are extrapolated down to a depth of ca. 12 km, along which we have plotted relocated seismicity. Combined geological and seismological data support a new 3D seismotectonic model, illustrating the propagation through time and space of the seismic ruptures during the sequence. Our results show that the litho-mechanical stratigraphy exerted a primary control on the distribution of seismicity, as it is mostly hosted in the more competent lithologies (i.e. the Late Triassic-Paleogene succession, consisting of carbonates and evaporites). In addition, we illustrate the crucial role played by the inherited compressional structures in determining the lateral and vertical variations of the rheological properties of the upper crust and, eventually, the overall geometry and segmentation of the seismogenic extensional system. The workflow proposed here can be applied to other seismogenic zones throughout the world, since reliable seismotectonic models require an accurate reconstruction of the subsurface geological setting, based on a close integration of geological, geophysical and seismological data.

Description: Published

Description: 228797

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

Description: JCR Journal

Description: Phonolite-trachyte associations are a common feature of alkaline volcanoes in intraplate settings, and their coexistence challenges closed-system magmatic differentiation scenarios. Here we have investigated the mineralogical and petrochemical features of dikes, lavas, pyroclastic deposits, and comagmatic crystal-rich enclaves outcropping at Dunedin Volcano (Otago region, southern New Zealand). These alkaline magmatic products show both highly and mildly alkaline affinities, trending towards phonolitic and trachytic end-members, respectively. Intermediate rocks are phonotephrites + tephriphonolites (highly alkaline series) and mugearites + benmoreites (mildly alkaline series) with a phenocryst assemblage of clinopyroxene + plagioclase ± amphibole formed at low to mid-crustal levels (i.e., ~29–16 km). Phonolites are porphyritic rocks characterized by alkali feldspar ± amphibole ± clinopyroxene. Their whole-rock compositions are highly enriched in incompatible elements, with variable Ba + Sr contents. A weak negative to slightly positive Eu anomaly is also associated with 87Sr/86Sr ratios of 0.7028–0.7031, which are comparable to those of parental magmas. Geochemical models indicate that phonolites originate as interstitial melts that are generated via abundant alkali feldspar crystallization from a shallow crystalline mush (i.e., ~14–5 km). Strong melt differentiation and extraction is testified by crystal-rich enclaves, as remnants of the mush region. On the other hand, trachytes are phenocryst-poor products strongly depleted in Ba + Sr and with a marked negative Eu anomaly. Trachytes are characterized by 87Sr/86Sr ratios of 0.7040–0.7060, which are different from intermediate rocks and phonolites, and trend towards crustal isotopic compositions. Integrated mass balance, trace element, and energy-constrained modeling confirm that trachytes originate from mildly alkaline magmas interacting with the country rock during feldspar fractionation. We interpret the transition from trachyte to phonolite formation and eruption resulting from the maturation of the plumbing system through accumulation, cooling, and degassing of both highly and mildly alkaline magmas.

Description: Published

Description: 106545

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: JCR Journal

Description: Despite Mt. Etna's long-standing reputation as an effusive volcano, since 1986 there has been an evident increase in mid-intensity explosive eruptions from its summit craters, with more than 240 episodes, better known as paroxysms (otherwise called paroxysmal episodes). These are characterized by strong Strombolian to lava fountaining activity that lasts from tens of minutes to a few days, producing some km-high volcanic plumes and tephra fallouts up to hundreds of km on the ground. Most paroxysms give life to sequences which are clustered like “episodic” eruptions for periods of a few days to a few months, their frequent recurrence causing hazard to air traffic and impacting densely inhabited areas. Nonetheless, a list containing the dates and data of these eruptions is lacking. In this paper, we tried to fill this gap by compiling a complete record, including master data (date, crater), eruption style and seismic parameters for identifying, characterizing and quantifying both the individual episodes and the entire period. This information comes from a critical review of surveillance reports, raw-data analysis and scientific literature. A retrieval of homogenous and comparable seismic data was possible only for episodes after 2006 following the renewal of seismic stations. The eruption list provides a complete picture of the 1986–2021 paroxysms, allowing to evaluate their temporal distribution, make a statistical analysis of their time-interval, and undertake a comprehensive investigation of the features of volcanic tremor. The results show a high probability (72%) of having a paroxysmal episode in the 10 days following the previous one. Moreover, a scaling relationship associated with the number-size distribution of the amplitude increases of volcanic tremor accompanying the explosive activities has been constrained. During sequences of paroxysms, combining these outputs can help improve the hazard assessment in terms of frequency of the associated tephra fallouts, and predict the duration of the entire sequence.

Description: Published

Description: 103686

Description: 1V. Storia eruttiva

Description: JCR Journal

Description: Eruptive columnmodels are powerful tools for investigating the transport of volcanic gas and ash, reconstructing past explosive eruptions, and simulating future hazards. However, the evaluation of these models is challenging as it requires independent estimates of themainmodel inputs (e.g.mass eruption rate) and outputs (e.g. column height). There exists no database of independently estimated eruption source parameters (ESPs) that is extensive, standardized, maintained, and consensus-based. This paper introduces the Independent Volcanic Eruption Source Parameter Archive (IVESPA, ivespa.co.uk), a community effort endorsed by the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Commission on Tephra HazardModelling.We compiled data for 134 explosive eruptive events, spanning the 1902-2016 period, with independent estimates of: i) total erupted mass of fall deposits; ii) duration; iii) eruption column height; and iv) atmospheric conditions. Crucially, we distinguish plume top versus umbrella spreading height, and the height of ash versus sulphur dioxide injection. All parameter values provided have been vetted independently by at least two experts. Uncertainties are quantified systematically, including flags to describe the degree of interpretation of the literature required for each estimate. IVESPA also includes a range of additional parameters such as total grain size distribution, eruption style, morphology of the plume (weak versus strong), and mass contribution from pyroclastic density currents, where available. We discuss the future developments and potential applications of IVESPA and make recommendations for reporting ESPs to maximize their usability across different applications. IVESPA covers an unprecedented range of ESPs and can therefore be used to evaluate and develop eruptive column models across a wide range of conditions using a standardized dataset.

Description: Published

Description: 107295

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal

Description: The topography of Mt. Etna, Italy, is subjected to continuous modifications depending on intensity and magnitude of eruptions that frequently occur at the volcano summit and flanks. In order to make high-resolution maps of morphological changes and accurately calculate the overall volume of the erupted products (e.g., lava flows, tephra fall out, scoriae cones) in ten years, we have compared the altimetry models of Mt. Etna derived from 2005 Airborne Laser Scanning data and 2015 Pleiades stereo satellite imagery. Both models cover a common area of 400 km2 with spatial resolution of 2 m and comparable vertical accuracy (RMSE 〈0.8 m). The results show that the area most affected by the erupted products is the mid-upper portion of the volcano with an altitude ranging from 1300 m to more than 3300 m a.s.l., value reached at the summit of the North East crater. In particular, this portion changes dramatically in the eastern sector due to the birth and growth of the New South- East Crater, the invasion of dozens of lava flows in the Valle del Bove, and the formation of the 2014 scoriae cones and lava field at the base of the North-East Crater. The total volume of products erupted in the investigated period results in 284.3±15.8 x 106 m3 with a yearly average volume of 28.4 x 106 m3/y comparable with the previous decades. In addition, the products emitted by the 2014 sub-terminal eruption are mapped and quantified including, for the first time, the volume of the 2014 scoriae cones generated on the eastern flank of North- East Crater This study demonstrates how a rigorous comparison between digital elevation models derived from different remote sensing techniques produce high accurate mapping and quantifications of morphological changes applicable for worldwide active volcanoes. This allows to quantify volumes and areas of erupted products reducing the error estimations, a crucial point to provide precise data often used as key parameters for many volcanic hazard studies.

Description: Published

Description: 102369

Description: 5IT. Osservazioni satellitari

Description: JCR Journal

Description: The CO2 concentration has been increasing for more than five decades reaching ~29 % at present with respect to the pre-industrial era. The largest CO2 cooling effects in the thermosphere are predicted for solar minimum conditions. A comparison of solar minima in 1954/1964 to the recent one in 2019 was used to check at the quantitative level the theoretical predictions and the validity of the CO2 cooling hypothesis. June monthly median noontime ionospheric observations at Moscow, Rome, and Slough/Chilton were used to infer neutral gas density ρ, exospheric temperature Tex, height of the F2-layer maximum hmF2, and total solar EUV flux for the (1954–2020) period. Solar and geomagnetic activity was shown to explain ~99 % of the whole variability in the retrieved neutral gas density and Tex during the (1958–2020) period resulting in statistically insignificant residual linear trends. A comparison of 1954/1964 to 2019 solar minima does not confirm the theoretically predicted decrease of ~21 % in ρ, ~15 K in Tex, and ~7 km in hmF2 related to a 29 % increase of the CO2 abundance. The main conclusion: despite continuous CO2 increase in the Earth's atmosphere long-term variations of thermospheric parameters are controlled by solar and geomagnetic activity.

Description: Published

Description: 105736

Description: 2A. Fisica dell'alta atmosfera

Description: JCR Journal

Description: Identifying the hydrological and environmental response of the European Alpine region to different combinations of climate boundary conditions is crucial to advance the reliability of predictive climate models and thus shape climate adaptation policies that will impact millions of people in seven countries. Here we present a high-resolution multiproxy speleothem record (stable oxygen and carbon isotope ratios, petrography and magnetic properties) from Rio Martino Cave (Piedmont, Southern Alps, Italy), which covers the first part of the Penultimate Glacial (early MIS 6, 182e157 ka). During early MIS 6, the combination of high climatic precession and obliquity amplified the peak in Northern Hemisphere (NH) summer insolation intensity at ca. 174 ka to almost interglacial levels, leading to northward migration of the Intertropical Convergence Zone and the enhancement of the boreal monsoon system. At orbital scale, the hydroclimatic record from Rio Martino closely follows the precession pattern, and shows a wet interstadial phase between 180 and 170 ka, peaking at the precession minimum, characterized by glacial retreat and by the likely development of soils and vegetation up to 1900e2000 m a.s.l. in this alpine sector. This phase can be traced across the Southern Alps, and corresponds to pluvial conditions inferred from Western Mediterranean records, and to the interval of deposition of the cold Sapropel S6 in the eastern Mediterranean. We suggest that the interaction between an intensified northwesterly cold flow (relating to increased ice volume under glacial conditions), and the relatively warm waters of the NW Mediterranean (due to the peculiar atmospheric configuration occurring at the precession minimum) strongly enhanced the autumn cyclogenesis in the Northern Tyrrhenian Sea, fuelling intense precipitation to reach the Southern Alps. The Rio Martino record also shows a prominent sub-orbital variability, the overall structure of which is coherent with hemispheric changes in climate driven by cyclic perturbations of North Atlantic conditions related to the operation of the bipolar seesaw.

Description: Published

Description: 106856

Description: 5A. Ricerche polari e paleoclima

Description: JCR Journal

Description: More than 100 years after the devasting Messina-Reggio Calabria earthquake (M = 7.1), the largest seismic event ever recorded in southern Europe in the instrumental epoch, its causative seismic source is still unknown, and the several rupture models proposed in the last decades are far from any shared solution. Data interpretation on a new dataset of sub-seafloor geophysical soundings with unprecedented resolution, relocated seismicity, and Vp model, together with morphotectonic investigations and inverse modelling of available levelling data, provide additional constraints on the deformation mechanisms and seismotectonics of the Strait of Messina area. Highresolution seismic lines in the offshore, along with displaced Quaternary marine terraces on land, point to active deformation along a previously unmapped ~34.5 km-long extensional fault. Spatial distribution of relocated earthquakes highlighted that a cut-off of the seismicity occurs within the crustal depth. The seismic discontinuity roughly delineates a foreland-dipping and low-angle discontinuity apparently confirming previous studies predicting low-angle seismogenic sources for the 1908 seismic event. However, according to the overburden stress and the attitude of the discontinuity, stress analysis suggests that a seismic slip is unlikely along it. This therefore weakens the hypothesis that a large earthquake may have nucleated along a low-angle discontinuity. Rather, aseismic creeping is instead expected since movement is allowed only by assuming a mechanical weakness of the plane. This mechanical behaviour is currently also supported by the large interseismic strain-rate recorded in the area. Both seismic tomography and crustal-to-subcrustal scale 3D-modelling strongly suggest a cause-and-effect relationship between slab retreat, mantle wedging, uplift in the upper plate block, and active extension in the Strait of Messina area. Lithospheric doming of the upper plate is here interpreted to be the main process controlling uplift in the Peloritani Mts. of Sicily and subsidence in the Strait of Messina region where deformation is mainly accommodated by the weak low-angle discontinuity. In this frame, an almost aseismical slip towards the foreland of the low-angle discontinuity is here accounted to produce stress perturbation in the area. Coulomb stress change modelling revealed that simulated normal slip on the foreland-dipping discontinuity can induce additional stress and promote failure in the overlying brittle faults. An excellent fit between calculated and observed subsidence is achieved by geodetic data inversion that resolved a normal slip on the low-angle discontinuity and a transtensional (slightly left-lateral) motion on the 34.5 km-long and previously unknown extensional fault. The fault-length along with the observed seafloor displacement make this tectonic structure as the most likely to have produced large earthquakes in the Strait of Messina area.

Description: Published

Description: 103685

Description: 2T. Deformazione crostale attiva

Description: JCR Journal

Description: Supported by evidence of deep crustal sources for the observed magnetic anomalies in Central Italy and by outcropping gabbros in the Croatian archipelago, we model the observed gravity and magnetic anomalies in the Central Adriatic Sea and surroundings. We suggest that the major magnetic anomalies in the area are related to a wide underplating and propose that this volume represents the first stage of the back-arc Adria continental breakup in Early Permian times. During the Palaeotethys-Adria collision, underplating has controlled topography and palaeogeographic domains resulting in the observed asymmetrical sedimentary evolution since the Triassic across the Adria microplate. Finally, we propose that the Palaeotethys-Adria boundary in the Early Permian was similar to the current Pacific-Okhotsk plate boundary.

Description: Published

Description: 105470

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: questionnaire to survey the common petrological monitoring procedures adopted by volcano monitoring insti- tutions has been developed, aimed at identifying prevailing techniques and rating their suitability in terms of costs versus benefits. The collected information resulted from a sample of eighteen participating institutions, which include countries with some of the most important active volcanic provinces worldwide. The participating institutions also offer insights into volcanoes with a variety of volcanic activity, providing a comprehensive pic- ture of the state of art of petrological monitoring. The final purposes are (i) to promote the advancement that pet- rologic monitoring brings in the comprehension of the eruptive processes, providing the only “signals” (i.e., rock samples) concerning the physico-chemical properties of the magma feeding the eruption; (ii) to design best practices, and (iii) to define the minimum requirements needed to perform an efficient petrological monitoring during ongoing eruptions. The survey also highlighted the main problems to overcome to have a profitable pet- rological monitoring infrastructure, including (i) the time required to accomplish both field survey and labora- tory works (sampling, sample preparation, and analyses), (ii) the lack of onsite analytical facilities, (iii) the shortage of qualified staff. Starting from the state of the art of petrological monitoring, how it is performed by the different institutions worldwide, and what participants considered as the major problems, we identified the Best Practices in Petrolog- ical Monitoring as the best compromise between fast and easy analyses and the relevance of the acquired results.

Description: Eurovolc

Description: Published

Description: 107365

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

Description: JCR Journal

Description: Machine learning is becoming increasingly important in scientific and technological progress, due to its ability to create models that describe complex data and generalize well. The wealth of publicly-available seismic data nowadays requires automated, fast, and reliable tools to carry out a multitude of tasks, such as the detection of small, local earthquakes in areas characterized by sparsity of receivers. A similar application of machine learning, however, should be built on a large amount of labeled seismograms, which is neither immediate to obtain nor to compile. In this study we present a large dataset of seismograms recorded along the vertical, north, and east components of 1487 broad-band or very broad-band receivers distributed worldwide; this includes 629,095 3-component seismograms generated by 304,878 local earthquakes and labeled as EQ, and 615,847 ones labeled as noise (AN). Application of machine learning to this dataset shows that a simple Convolutional Neural Network of 67,939 parameters allows discriminating between earthquakes and noise single-station recordings, even if applied in regions not represented in the training set. Achieving an accuracy of 96.7, 95.3, and 93.2% on training, validation, and test set, respectively, we prove that the large variety of geological and tectonic settings covered by our data supports the generalization capabilities of the algorithm, and makes it applicable to real-time detection of local events. We make the database publicly available, intending to provide the seismological and broader scientific community with a benchmark for time-series to be used as a testing ground in signal processing.

Description: Published

Description: 1-10

Description: 1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami

Description: N/A or not JCR

Description: After the 2004 Indian Ocean (IOT) and the 2011 Tohoku-oki tsunamis, new research in tsunami-related fields was strongly stimulated worldwide and also in the Mediterranean. This research growth yields substantial advancements in tsunami knowledge. Among these advancements is the “Paleotsunami” research that has marked particular progress on the reconstruction of the tsunami history of a region. As an integration of the historical documentation available in the Mediterranean and the Gulf of Cadiz areas, geological and geoarchaeological records provide the insights to define the occurrence, characteristics, and impact of tsunamis of the past. Here, we present the recent advancements done for both the onshore and offshore realms. As for the onshore, we discuss case studies dealing with recent high-resolution works based on: a) direct push in situ sensing techniques, applied to identification and characterization of typical paleotsunami deposits features; b) combined XRF- X-CT approach, implemented for the identification of fine-scale sedimentary structures useful for the definition of the causative flow dynamics; c) the geoarchaeological “new field” contribution, with the development of specific diagnostic criteria in search for tsunami impact traces in archaeological strata; d) comparison of multiple dating methods and of different modeling codes for the definition of the potential source for the displacement of boulders of exceptional dimension, identified by 3D size calculation. As for the offshore advancements, we present case studies focusing on the recognition of tsunami deposits and their sedimentary traces in the geological record from the nearshore, thanks to diver-operated coring equipment, down to the continental slope, by means of vibracorer and long gravity core sampling in deeper areas. The examples provided show a multiproxy approach with a high potential of retrieving a complete record of paleotsunami traces at least during the Holocene. This is based on the combination of multidisciplinary approaches including X-ray imaging, high-resolution measurement of physical properties, X- ray fluorescence data, grain-size analysis, micropaleontology, palynological content, isotopic and optically stimulated luminescence dating methods.

Description: Published

Description: 103578

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

Description: JCR Journal

Description: Landslides are widespread natural phenomena that play an important role in landscape evolution and are responsible for several casualties and damages. Slope instability is linked to the combination of geological, geomorphological, and climatic factors with various triggering mechanisms; among these, seismic shaking can induce relevant changes in the landscape, leading to coseismic and post-seismic phenomena such as landslide events. The Abruzzo Region (Central Italy) is severely affected by Earthquake-Induced Landslides (EILs), linked to the geomorphological dynamics and the severe seismicity of the area. The distribution, mechanisms, and typology of landslides are strictly related to the different physiographic and geological-structural settings. This paper focuses on the realisation of an EILs susceptibility map, following a heuristic approach combined with a statistical analysis, integrated using GIS technology. This approach led to the identification of nine instability factors. These factors were analysed for the construction of thematic maps. Hence, each factor was assigned proper expert-based ranks and weights based on the critical evaluation of literature data as well as on available landslide inventories and combined in a preliminary map wherein high/low numerical values correspond to a high/low propensity of the slope to fail; furthermore, a statistical analysis of these values was performed to derive suitable susceptibility classes. Results presented herein highlight the robustness of the approach; remarkably, the applied methodology is suitable even in areas where a detailed landslide catalogue is lacking, when the same classification and weighting of available parameters is performed. The statistical analyses and the adoption of an absolute scale ranging from minimum to maximum potential values, finally, ensures the comparability of results among different study areas. Finally, this work represents a scientific and multidisciplinary tool for better defining situations that could lead to hazards (such as landslides) following an earthquake to develop sustainable territorial planning, emergency management, and loss-reduction measures.

Description: Published

Description: 105729

Description: 2T. Deformazione crostale attiva

Description: JCR Journal

Description: The needs of society and the emerging blue economy require access and integration of data and information for the construction of dedicated products. A “transparent and accessible ocean” is one of the key objectives of the Ocean Decade 2021–30. In this context, marine infrastructures become significant components of a global knowledge environment, enabling environmental assessment and providing the necessary data for scientifically valid actions to protect and restore ocean health, to use marine resources in a sustainable way. The data is collected, analyzed, organized, and used by people and their good use/reuse can be obtained with social practices, technological and physical agreements aimed at facilitating collaborative knowledge, decision-making, inference. The vision is a digital ocean data ecosystem made up of multiple, interoperable, and scalable components. The huge amount of data and the resulting products can drive the development of new knowledge as well as new applications and services. Predictive capabilities that derive from the digital ecosystem enable the implementation of services for real-time decision-making, multihazard warning systems, and advance marine space planning. The chapter develops following the progressive complexity and information content of products deriving from oceanic data: data cycle and data collections, data products, oceanic reanalysis. The chapter discusses the new challenges of data products and the complexity of deriving them.

Description: Published

Description: 197-280

Description: 4A. Oceanografia e clima

Description: Lava flows are recurring and widespread hazards that affect areas around active volcanoes, having the potential to cause significant social and economic loss. The ongoing demographic congestion around volcanoes increases the potential risk and leads to a growing demand for faster and more accurate systems to safeguard the population. The main mitigation action for slowing down and possibly diverting lava flows is the building of artificial barriers, that can limit their destructive effects and reduce losses. Here we present a Particle Swarm Optimization algorithm for the configuration of artificial barriers, in terms of location and geometric features. The goal is to minimize the lava flow impact based on the spatial distribution of exposed elements, using the physics-based MAGFLOW model to run the lava flow scenarios for each barrier configuration. Our algorithm has been tested on Etna (Italy), showing how it can effectively safeguard the threatened areas, diverting lava away from them.

Description: Published

Description: 105023

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

Description: JCR Journal

Description: Between 9 March and 18 May 2020, strict lockdown measures were adopted in Italy for containing the COVID-19 pandemic: in Rome, despite vehicular traffic on average was more than halved, it was not observed a evident decrease of the airborne particulate matter (PM) concentrations, as assessed by air quality data. In this study, daily PM10 filters were collected from selected automated stations operated in Rome by the regional network of air quality monitoring: their magnetic properties - including magnetic susceptibility, hysteresis parameters and FORC (first order reversal curves) diagrams - were compared during and after the lockdown, for outlining the impact of the COVID-19 measures on airborne particulate matter. In urban traffic sites, the PM10 concentrations did not significantly change after the end of the lockdown, when vehicular traffic promptly returned to its usual levels; conversely, the average volume and mass magnetic susceptibilities approximately doubled, and the linear correlation between volume magnetic susceptibility and PM10 concentration became significant, pointing out the link between PM10 concentrations and the increasing levels of traffic-related magnetic emissions. Magnetite-like minerals, attributed to non-exhaust brakes emissions, dominated the magnetic fraction of PM10 near urban traffic sites, with natural magnetic components emerging in background sites and during exogenous dusts atmospheric events. Magnetic susceptibility constituted a fast and sensitive proxy of vehicular particulate emissions: the magnetic properties can play a relevant role in the source apportionment of PM10, especially when unsignificant variations in its concentration levels may mask important changes in the traffic-related magnetic fraction. As a further hint, increasing attention should be drawn to the reduction of brake wear emissions, that are overcoming by far fuel exhausts as the main particulate pollutant in traffic contexts.

Description: Published

Description: 118191

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: The youngest (last 1500 years) volcanic eruptions of Lipari, within the Aeolian Archipelago, produced the prominent pumice cone of Monte Pilato and the obsidian lava flows of Rocche Rosse and Forgia Vecchia, concentrated in the north-eastern sector of the island as well as highly dispersed white-coloured, fine-grained tephra layers of rhyolitic composition in terrestrial and marine settings on the regional scale. Here we describe in detail the stratigraphy of pyroclastic successions and lava flows erupted by different vents - Monte Pilato, Forgia Vecchia, Lami, and Rocche Rosse - combining field observations, sedimentological characteristics of the tephra deposits, and major and trace element compositions of the volcanic glass. All the pyroclastic materials consist of aphyric pumice lapilli and ash with a largely homogeneous rhyolitic composition. The Monte Pilato and Forgia Vecchia deposits primarily consist of highly vesicular pumice fragments and subordinate obsidian clasts, whilst Rocche Rosse and Lami are characterized by moderately vesicular juvenile fragments with a more significant fraction of obsidian. The Lami tephra also contains peculiar pumice clasts with a fibrous texture and breadcrust bombs. Stratigraphic relationships, and paleomagnetic and 14C ages of the lava and pyroclastic deposits are combined with the archaeological information and historical reports, enabling us to provide an accurate chrono-stratigraphic framework for the youngest eruptions of Lipari. Following the 8th century CE eruption of Monte Pilato, which produced a pumice cone and a obsidian lava flow, activity resumed in the second half of 13th century CE with the explosive eruption of Forgia Vecchia that culminated in the emission of a bilobate obsidian lava flow. This eruption was shortly followed by the explosive eruptions of Lami and Rocche Rosse, the latter concluded with the emission of the widely renowned obsidian lava flow. By integrating stratigraphy and geochemistry of tephra deposits with a new chronological scheme, our work facilitates the refinement of proximal-to-distal correlation of Lipari's rhyolitic tephra in continental marine environments of the central Mediterranean area in the last 1500 years. A fine-grained, rhyolitic ash found on Stromboli (~40 km NE from Lipari) has an origin from the Monte Pilato and thus, constrains tephra dispersion towards the NE. Very similar ash beds dispersed southwards and interlayered within the near-source deposits of La Fossa, Vulcano island (~10 km from Lipari) exhibit features that are consistent with the younger activities of the Rocche Rosse eruption. A possible link between previously identified rhyolitic ash layers identified in marine cores of the Ionian Sea and the Forgia Vecchia eruption are postulated, although the age and textural characteristics of these distal tephra are not univocal in indicating a correlation to either Monte Pilato or Forgia Vecchia.

Description: Published

Description: 107397

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: Volcanic gas dispersal can be a serious threat to people living near active volcanoes since it can have short- and long-term effects on human health, and severely damage crops and agricultural land. In recent decades, reliable computational models have significantly advanced, and now they may represent a valuable tool to make quan- titative and testable predictions, supporting gas dispersal forecasting and hazard assessments for public safety. Before applying a specific modelling tool into hazard quantification, its calibration and its sensitivity to initial and boundary conditions should be carefully tested against available data, in order to produce unbiased hazard quantifications. In this study, we provided a number of prototypical tests aimed to validate the modelling of gas dispersal from a hazard perspective. The tests were carried out at La Soufrière de Guadeloupe volcano, one of the most active gas emitters in the Lesser Antilles. La Soufrière de Guadeloupe has shown quasi-permanent degassing of a low-temperature hydrothermal nature since its last magmatic eruption in 1530 CE, when the current dome was emplaced. We focused on the distribu- tion of CO2 and H2S discharged from the three main present-day fumarolic sources at the summit, using the mea- surements of continuous gas concentrations collected in the period March–April 2017. We developed a new probabilistic implementation of the Eulerian code DISGAS-2.0 for passive gas dispersion coupled with the mass-consistent Diagnostic Wind Model, using local wind measurements and atmospheric stability information from a local meteorological station and ERA5 reanalysis data. We found that model outputs were not significantly affected by the type of wind data but rather upon the relative positions of fumaroles and measurement stations. Our results reproduced the statistical variability in daily averages of observed data over the investigated period within acceptable ranges, indicating the potential usefulness of DISGAS-2.0 as a tool for reproducing the observed fumarolic degassing and for quantifying gas hazard at La Soufrière. The adopted testing procedure allows for an aware application of simulation tools for quantifying the hazard, and thus we think that this kind of testing should actually be the first logical step to be taken when applying a simulator to assess (gas) hazard in any other volcanic contexts.

Description: Published

Description: 107312

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

Description: JCR Journal

Description: In this work, we propose a wavelet-based filtering for soil CO2 flux time series. The filter relies on the detection of the periodic components achieved by means of the long-term time-frequency characterization of the time series. For this purpose, we exploited the vast data set coming from the monitoring network installed at Mt. Etna volcano (Italy). The network provides hourly measure of CO2 flux together with the measure of the climatic variables. These data allow to investigate the relationships between CO2 time series and the potentially influencing meteorological factors. This has been assessed calculating the wavelet coherence between CO2 time series against air temperatures, atmospheric pressure, and relative humidity in all the sites where these information were available. Results highlight the occurrence of marked cycles at about ∼1 year for the most of the sites while shorter cycles occur only at some sites. From these cycles a periodic signal can be calculated, and therefore opportunely removed from the time CO2 series to enhance the volcano-related anomalies. We found also common cycles among CO2 and the climatic variables, which synchronicity is constant over time but it is site-specific. Starting from this consideration, we calculated a reference signal for CO2 combining analytically the temperature, the pressure, and the humidity cycles: this model of the climatic effect has been used to predict the seasonal trend of the CO2 output.

Description: Published

Description: 107421

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: JCR Journal

Description: Seismic stations are usually used to record seismic event and, therefore, they are recommended to be installed far from railways and traffic roads in order to avoid the superposition of ambient noise signals to those provoked by an earthquake. In this paper, instead, seismic stations, placed intentionally in areas near railway and traffic roads, are used to characterize the subsoil spectral properties and to assess the effect of vibrations due to trains and vehicles. A cemetery in the green countryside near Florence is chosen as a reference case study to deal with this topic. Most of the buildings in the cemetery area are affected by an extensive crack pattern. In January 2020 five seismic stations were installed in order to evaluate if the trains running in the tunnels of the regional and high-speed railway lines located below and in the vicinity of the cemetery and the vehicles traveling on the nearby A1 highway and regional road can produce vibrations in the ground that justify the observed damage pattern. Collected data are analyzed using the Nakamura technique in order to estimate the dynamic properties of the ground and compared to the limits provided by the current regulations. Furthermore, the trend of the Root Mean Square average over the entire recording period is computed as well. From the obtained results, it is possible to highlight that the average daily oscillation level increases from early morning until 7 p.m. and then it decreases, and also that the highest am­ plitudes of transients are concentrated in the late evening and during the night, when the background noise is lower. Furthermore, the computed values of the maximum and average amplitudes are lower than those that can cause damage to buildings as defined by the guidelines, the eigenfrequency of the ground falls in a range far from that ascribable to the cemetery buildings, so that the resonance effects can be excluded. In order to confirm these results, the amplitude of ground shaking due to recorded transients is compared to that produced by two earthquakes (a 3.4 Mw local earthquake at more than 100 km and a Mw 6.6 teleseism from Turkey) which occurred during the monitoring period. One can conclude that it seems unlikely that the shaking produced by nearby vehicles and trains could be responsible for the observed damage.

Description: The study was partially funded by the Municipality of Figline-Incisa Valdarno.

Description: Published

Description: e00623

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

Description: JCR Journal

Description: The eruptive activity of a volcano modifies its surface topography through morphological changes generated by the deposition of emitted volcanic material and resulting gravity-driven processes,which can form accumulation of material in addition to the most common erosional phenomena. Mapping and quantifying such morphological changes allow to derive new data useful to better describe and understand the eruptive history of the volcano itself. Nowadays, one of the mostly used method to identify such morphological changes consists of comparing Digital Elevation Models (DEM) of the volcanic area before and after an eruptive event. If the eruptive event is referred to periods prior to 1980's, the only method to reproduce DEMs consists of elaborating the historical cartography that is often available only in paper format. In thisworkwe aimto prove the reliability of this approach, presenting a study on the morphological changes (from 1876 to 1944) of the summit caldera of the Somma–Vesuvio volcano (Italy). For the first time, we compare DEMs derived from historical maps (1876, 1906 and1929) and a DEM dated 2012 obtained by remote sensing. The four models of the caldera, digitally reproducedat the same spatial resolution, are morphologically investigated through specific maps derived from the DEMs and a set of height profiles. In addition, further morphometric analyses and accurate quantifications in volume and surface are presented and discussed for a portion of the Somma-Vesuvio summit caldera, represented by the Gran Cono edifice. Considering the different typology of the source data used in this study, it is also provided a discussion on the respective accuracies that, especially for the historical maps, represent a crucial point for obtaining DEMs able to reproduce topographies more realistic as possible. For this reason, despite data source were processed following rigours criteria, the calculations of volume, surface and distance related to the morphological changes of the volcano are associated to an accurate quantification of the error. Following this, the main results obtained in this study are: i) the identification of several past volcanic deposits and the estimation of the related thicknesses, both in good agreement with published literature; ii) the quantification of the morphological changes of theGran Cono from 1876 to 1944 resulting in a volume and surface growth of 133 ×106m3(±5%) and ~0.14 km2, respectively; iii) the identification of a possible migration path of the centroid of the Gran Cono crater along the SW-NE preferential direction during the investigated period.

Description: Published

Description: 107624

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

Description: JCR Journal

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Melle, W., Klevjer, T., Strand, E., Wiebe, P. H., Slotte, A., & Huse, G. Fine-scale observations of physical and biological environment along a herring feeding migration route. Deep-Sea Research Part II: Topical Studies in Oceanography, 180, (2020): 104845, doi:10.1016/j.dsr2.2020.104845.

Description: We observed herring horizontal and vertical distribution during feeding migration along a 128 km transect across the Arctic front of the Norwegian and Iceland seas, in early June, in relation to its physical, chemical and biological environment, distribution of prey organisms and pelagic and mesopelagic competitors. The Norwegian Spring Spawning herring is one of the largest and economically most important stocks of pelagic fish in the world and understanding what controls its feeding migration is, and has been for centuries, a major research question that also has major implications for management. High resolution ecosystem data were obtained by hull mounted multi-frequency acoustics and a towed platform undulating between 10 and 400 m equipped with multi-frequency acoustics, temperature, salinity and fluorescence sensors, an Optical Plankton Counter and a Video Plankton Recorder. Additional sampling was done by MOCNESS, Macroplankton trawl, and CTD equipped with water bottles for temperature, salinity, nutrients and chlorophyll at discrete stations along the transect. Biological characteristics and stomach content of the herring were obtained from samples at discrete trawl stations. The Arctic front proved to be an important transitional zone in zooplankton biomass, abundance and diversity. Phenology of phyto- and zooplankton also changed across the front, being somewhat delayed on the cold side. The herring were distributed all along the transect showing a shallow distribution on the warm side and both deep and shallow on the cold side, not clearly related to light and time of the day. The herring stomach content was higher on the cold side. There was no significant pattern in average age, weight, or body length of the herring along the transect. The herring were present and fed in the area of the transect during the time when the overwintering generation of Calanus finmarchicus dominated, before the development of the new generation of the year. We suggest that the phenology of C. finmarchicus can be an important driver of the herring feeding migration. While prey-availability was higher on the Arctic side of the front, light conditions for visual feeding at depth were probably better on the Atlantic side. The herring did not show classical dial vertical migration, but its prey did, and the herring's prey were probably available within the upper 100 m during the course of a 24 h cycle. With a general westward direction of migration, the herring along the transect moved towards lower temperatures and temperature did not seem to be a probable driver for migration. We conclude that fine-scale studies of herring migration and feeding can increase our understanding of the migratory processes and add to our understanding of large-scale distributional patterns, changes therein, and herring trophodynamics and ecological role. The fine-resolution parameters can also be important as input to ecosystem models.

Description: We would also like to acknowledge the funding from Euro-BASIN, EU FP7, Grant agreement No 264933, HARMES, Research Council of Norway project number 280546 and MEESO, EU H2020 research and innovation programme, Grant Agreement No 817669.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Lin, H., Tarnas, J. D., Mustard, J. F., Zhang, X., Wei, Y., Wan, W., Klein, F., & Kellner, J. R. Dynamic aperture factor analysis/target transformation (DAFA/TT) for Mg-serpentine and Mg-carbonate mapping on Mars with CRISM near-infrared data. Icarus, 355, (2021): 114168, https://doi.org/10.1016/j.icarus.2020.114168.

Description: Serpentine and carbonate are products of serpentinization and carbonation processes on Earth, Mars, and other celestial bodies. Their presence implies that localized habitable environments may have existed on ancient Mars. Factor Analysis and Target Transformation (FATT) techniques have been applied to hyperspectral data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to identify possible serpentine and Mg-carbonate-bearing outcrops. FATT techniques are capable of suggesting the presence of individual spectral signals in complex spectral mixtures. Applications of FATT techniques to CRISM data thus far only evaluate whether an entire analyzed image (≈ 3 × 105 pixels) may contain spectral information consistent with a specific mineral of interest. The spatial distribution of spectral signal from the possible mineral is not determined, making it difficult to validate a reported detection and also to understand the geologic context of any purported detections. We developed a method called Dynamic Aperture Factor Analysis/Target Transformation (DAFA/TT) to highlight the locations in a CRISM observation (or any similar laboratory or remotely acquired data set) most likely to contain spectra of specific minerals of interest. DAFA/TT determines the locations of possible target mineral spectral signals within hyperspectral images by performing FATT in small moving windows with different geometries, and only accepting pixels with positive detections in all cluster geometries as possible detections. DAFA/TT was applied to a hyperspectral image of a serpentinite from Oman for validation testing in a simplified laboratory setting. The mineral distribution determined by DAFA/TT application to the laboratory hyperspectral image was consistent with Raman analysis of the serpentinite sample. DAFA/TT also successfully mapped the spatial distribution of Mg-serpentine and Mg-carbonate previously detected in CRISM data using band parameter mapping and extraction of ratioed spectra. We applied DAFA/TT to CRISM images in some olivine-rich regions of Mars to characterize the spatial distribution of Mg-serpentine and Mg-carbonate-bearing outcrops.

Description: This work was supported by the National Natural Science Foundation of China (grant no. 41671360, 41525016, 41902318). JFM and JDT acknowledge NASA support through a subcontract from the Applied Physics Lab for CRISM investigations. H. Lin also acknowledges the support from the key research Program of the Institute of Geology and Geophysics, CAS (IGGCAS-201905). The Headwall imaging spectrometer was acquired using funds to JRK from The Institute at Brown for Environment and Society and Brown University. The DAFA/TT codes are available on GitHub (https://github.com/linhoml?tab=repositories).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gu, S., Liu, Z., Oppo, D. W., Lynch-Stieglitz, J., Jahn, A., Zhang, J., Lindsay, K., & Wu, L. Remineralization dominating the δ13 C decrease in the mid-depth Atlantic during the last deglaciation. Earth and Planetary Science Letters, 571, (2021): 117106, https://doi.org/10.1016/j.epsl.2021.117106.

Description: δ 13 C records from the mid-depth Atlantic show a pronounced decrease during the Heinrich Stadial 1 (HS1), a deglacial episode of dramatically weakened Atlantic Meridional Ocean Circulation (AMOC). Proposed explanations for this mid-depth decrease include a greater fraction of δ 13 C -depleted southern sourced water (SSW), a δ 13 C decrease in the North Atlantic Deep Water (NADW) end-member, and accumulation of the respired organic carbon. However, the relative importance of these proposed mechanisms cannot be quantitatively constrained from current available observations alone. Here we diagnose the individual contributions to the deglacial Atlantic mid-depth δ 13 C change from these mechanisms using a transient simulation with carbon isotopes and idealized tracers. We find that although the fraction of the low- δ 13 C SSW increases in response to a weaker AMOC during HS1, the water mass mixture change only plays a minor role in the mid-depth Atlantic δ 13 C decrease. Instead, increased remineralization due to the AMOC-induced mid-depth ocean ventilation decrease is the dominant cause. In this study, we differentiate between the deep end-members, which are assigned to deep water regions used in previous paleoceanography studies, and the surface end-members, which are from the near-surface water defined from the physical origin of deep water masses. We find that the deep NADW end-member includes additional remineralized material accumulated when sinking from the surface (surface NADW end-member). Therefore, the surface end-members should be used in diagnosing mechanisms of changes. Furthermore, our results suggest that remineralization in the surface end-member is more critical than the remineralization along the transport pathway from the near-surface formation region to the deep ocean, especially during the early deglaciation.

Description: This work is supported by US National Science Foundation (NSF) P2C2 projects (1401778, 1401802, and 1566432), and the National Science Foundation of China No. 41630527. S.G. is supported by Shanghai Pujiang 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 Anderson, D. M., Fensin, E., Gobler, C. J., Hoeglund, A. E., Hubbard, K. A., Kulis, D. M., Landsberg, J. H., Lefebvre, K. A., Provoost, P., Richlen, M. L., Smith, J. L., Solow, A. R., & Trainer, V. L. Marine harmful algal blooms (HABs) in the united states: history, current status and future trends. Harmful Algae, 102, (2021): 101975, https://doi.org/10.1016/j.hal.2021.101975.

Description: Harmful algal blooms (HABs) are diverse phenomena involving multiple. species and classes of algae that occupy a broad range of habitats from lakes to oceans and produce a multiplicity of toxins or bioactive compounds that impact many different resources. Here, a review of the status of this complex array of marine HAB problems in the U.S. is presented, providing historical information and trends as well as future perspectives. The study relies on thirty years (1990–2019) of data in HAEDAT - the IOC-ICES-PICES Harmful Algal Event database, but also includes many other reports. At a qualitative level, the U.S. national HAB problem is far more extensive than was the case decades ago, with more toxic species and toxins to monitor, as well as a larger range of impacted resources and areas affected. Quantitatively, no significant trend is seen for paralytic shellfish toxin (PST) events over the study interval, though there is clear evidence of the expansion of the problem into new regions and the emergence of a species that produces PSTs in Florida – Pyrodinium bahamense. Amnesic shellfish toxin (AST) events have significantly increased in the U.S., with an overall pattern of frequent outbreaks on the West Coast, emerging, recurring outbreaks on the East Coast, and sporadic incidents in the Gulf of Mexico. Despite the long historical record of neurotoxic shellfish toxin (NST) events, no significant trend is observed over the past 30 years. The recent emergence of diarrhetic shellfish toxins (DSTs) in the U.S. began along the Gulf Coast in 2008 and expanded to the West and East Coasts, though no significant trend through time is seen since then. Ciguatoxin (CTX) events caused by Gambierdiscus dinoflagellates have long impacted tropical and subtropical locations in the U.S., but due to a lack of monitoring programs as well as under-reporting of illnesses, data on these events are not available for time series analysis. Geographic expansion of Gambierdiscus into temperate and non-endemic areas (e.g., northern Gulf of Mexico) is apparent, and fostered by ocean warming. HAB-related marine wildlife morbidity and mortality events appear to be increasing, with statistically significant increasing trends observed in marine mammal poisonings caused by ASTs along the coast of California and NSTs in Florida. Since their first occurrence in 1985 in New York, brown tides resulting from high-density blooms of Aureococcus have spread south to Delaware, Maryland, and Virginia, while those caused by Aureoumbra have spread from the Gulf Coast to the east coast of Florida. Blooms of Margalefidinium polykrikoides occurred in four locations in the U.S. from 1921–2001 but have appeared in more than 15  U.S. estuaries since then, with ocean warming implicated as a causative factor. Numerous blooms of toxic cyanobacteria have been documented in all 50  U.S. states and the transport of cyanotoxins from freshwater systems into marine coastal waters is a recently identified and potentially significant threat to public and ecosystem health. Taken together, there is a significant increasing trend in all HAB events in HAEDAT over the 30-year study interval. Part of this observed HAB expansion simply reflects a better realization of the true or historic scale of the problem, long obscured by inadequate monitoring. Other contributing factors include the dispersion of species to new areas, the discovery of new HAB poisoning syndromes or impacts, and the stimulatory effects of human activities like nutrient pollution, aquaculture expansion, and ocean warming, among others. One result of this multifaceted expansion is that many regions of the U.S. now face a daunting diversity of species and toxins, representing a significant and growing challenge to resource managers and public health officials in terms of toxins, regions, and time intervals to monitor, and necessitating new approaches to monitoring and management. Mobilization of funding and resources for research, monitoring and management of HABs requires accurate information on the scale and nature of the national problem. HAEDAT and other databases can be of great value in this regard but efforts are needed to expand and sustain the collection of data regionally and nationally.

Description: Support for DMA, MLR, and DMK was provided through the Woods Hole Center for Oceans and Human Health (National Science Foundation grant OCE-1840381 and National Institutes of Health grants NIEHS‐1P01-ES028938–01) and the U.S. National Office for Harmful Algal Blooms with funding from NOAA's National Centers for Coastal Ocean Science (NCCOS) through the Cooperative Institute for the North Atlantic Region (CINAR) (NA14OAR4320158, NA19OAR4320074). Funding for KAL and DMA was provided by the National Oceanic and Atmospheric Administration National Centers for Coastal Ocean Science Competitive Research Program under award NA20NOS4780195 to the Woods Hole Oceanographic Institution and NOAA's Northwest Fisheries Science Center. We also acknowledge support for A.H. from the National Oceanic and Atmospheric Administration [NOAA] Office of Ocean and Coastal Resource Management Award NA19NOS4780183, C.J.G from NOAA-MERHAB (NA19NOS4780186) and (NA16NOS4780189) for VLT Support was also received for JLS, CJG, and VLT from NOAA-NCCOS-ECOHAB under awards NA17NOS4780184 and NA19NOS4780182. This is ECOHAB publication number ECO972.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Rzucidlo, C. L., Sperou, E. S., Holser, R. R., Khudyakov, J., Costa, D. P., & Crocker, D. E. Changes in serum adipokines during natural extended fasts in female northern elephant seals. General and Comparative Endocrinology, 308, (2021): 113760, https://doi.org/10.1016/j.ygcen.2021.113760.

Description: Adipose tissue is essential to endotherms for thermoregulation and energy storage as well as functioning as an endocrine organ. Adipose derived hormones, or adipokines, regulate metabolism, energy expenditure, reproduction, and immune function in model systems but are less well studied in wildlife. Female northern elephant seals (NES) achieve high adiposity during foraging and then undergo natural fasts up to five weeks long during haul-outs associated with reproduction and molting, resulting in large changes in adipose reserves. We measured circulating levels of four adipokines: leptin, resistin, adiponectin, and kisspeptin-54, in 196 serum samples from female NES at the beginning and end of their breeding and molting fasts. We examined the relationships between these adipokines and life-history stage, adiposity, mass, cortisol, and an immune cytokine involved in the innate immune response interleukin 6 (IL-6). All four adipokines varied with life-history stage. Leptin concentrations were highest at the beginning of the breeding haul-out. Resistin concentrations were higher throughout the breeding haul-out compared to the molt haul-out. Adiponectin concentrations were highest at the beginning of both haul-outs. Kisspeptin-54 concentrations were highest at the end of the breeding haul-out. Leptin, resistin, and adiponectin were associated with measures of body condition, either adiposity, mass, or both. Resistin, adiponectin, and kisspeptin-54 were associated with circulating cortisol concentrations. Resistin was strongly associated with circulating IL-6, a multifunctional cytokine. Adiponectin was associated with glucose concentrations, suggesting a potential role in tissue-specific insulin sensitivity during life-history stages categorized by high adiposity. Increased cortisol concentrations late in lactation were associated with increased kisspeptin-54, suggesting a link to ovulation initiation in NES. This study suggests dramatic changes in circulating adipokines with life-history and body condition that may exert important regulatory roles in NES. The positive relationship between adiponectin and adiposity as well as the lack of a relationship between leptin and kisspeptin-54 differed from model systems. These differences from biomedical model systems suggest the potential for modifications of expression and function of adipose-derived hormones in species that undergo natural changes in adiposity as part of their life-history.

Description: This project was supported by a grant from the Office of Naval Research (#N00014-18-1-2822) to DPC and DEC and the Marine Life Joint Industry Program of the IAGOP. We thank the Año Nuevo State Reserve rangers for logistical support.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gomaa, F., Utter, D. R., Powers, C., Beaudoin, D. J., Edgcomb, V. P., Filipsson, H. L., Hansel, C. M., Wankel, S. D., Zhang, Y., & Bernhard, J. M. Multiple integrated metabolic strategies allow foraminiferan protists to thrive in anoxic marine sediments. Science Advances, 7(22), (2021): eabf1586, https://doi.org/10.1126/sciadv.abf1586.

Description: Oceanic deoxygenation is increasingly affecting marine ecosystems; many taxa will be severely challenged, yet certain nominally aerobic foraminifera (rhizarian protists) thrive in oxygen-depleted to anoxic, sometimes sulfidic, sediments uninhabitable to most eukaryotes. Gene expression analyses of foraminifera common to severely hypoxic or anoxic sediments identified metabolic strategies used by this abundant taxon. In field-collected and laboratory-incubated samples, foraminifera expressed denitrification genes regardless of oxygen regime with a putative nitric oxide dismutase, a characteristic enzyme of oxygenic denitrification. A pyruvate:ferredoxin oxidoreductase was highly expressed, indicating the capability for anaerobic energy generation during exposure to hypoxia and anoxia. Near-complete expression of a diatom’s plastid genome in one foraminiferal species suggests kleptoplasty or sequestration of functional plastids, conferring a metabolic advantage despite the host living far below the euphotic zone. Through a unique integration of functions largely unrecognized among “typical” eukaryotes, benthic foraminifera represent winning microeukaryotes in the face of ongoing oceanic deoxygenation.

Description: his project was funded by the U.S. NSF IOS 1557430 and 1557566. H.L.F. acknowledges support from the Swedish Research Council VR (grant number 2017-04190).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Le Roux, V., Urann, B. M., Brunelli, D., Bonatti, E., Cipriani, A., Demouchy, S., & Monteleone, B. D. Postmelting hydrogen enrichment in the oceanic lithosphere. Science Advances, 7(24), (2021): eabf6071, https://doi.org/10.1126/sciadv.abf6071.

Description: The large range of H2O contents recorded in minerals from exhumed mantle rocks has been challenging to interpret, as it often records a combination of melting, metasomatism, and diffusional processes in spatially isolated samples. Here, we determine the temporal variations of H2O contents in pyroxenes from a 24-Ma time series of abyssal peridotites exposed along the Vema fracture zone (Atlantic Ocean). The H2O contents of pyroxenes correlate with both crustal ages and pyroxene chemistry and increase toward younger and more refractory peridotites. These variations are inconsistent with residual values after melting and opposite to trends often observed in mantle xenoliths. Postmelting hydrogen enrichment occurred by ionic diffusion during cryptic metasomatism of peridotite residues by low-degree, volatile-rich melts and was particularly effective in the most depleted peridotites. The presence of hydrous melts under ridges leads to widespread hydrogen incorporation in the oceanic lithosphere, likely lowering mantle viscosity compared to dry models.

Description: Funding for this study was supported by NSF EAR-P&G 1524311 and 1839128 to V.L.R. and the Andrew W. Mellon Foundation Award for Innovative Research to V.L.R. A.C. and D.B. were funded by the Italian Programma di Rilevante Interesse Nazionale PRIN 20178LPCPW and PRIN2017KY5ZX8, respectively. Revisions were performed within the duration of a “Visiting Scholar at SCIENCE 2020” award to V.L.R. (University of Copenhagen, Denmark), with support from the Department of Geosciences and Natural Resource Management, Section for Geology.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Foppe, K. S., Kujawinski, E. B., Duvallet, C., Endo, N., Erickson, T. B., Chai, P. R., & Matus, M. Analysis of 39 drugs and metabolites, including 8 glucuronide conjugates, in an upstream wastewater network via HPLC-MS/MS. Journal of Chromatography B, 1176, (2021): 122747, https://doi.org/10.1016/j.jchromb.2021.122747.

Description: Pharmaceutical compounds ingested by humans are metabolized and excreted in urine and feces. These metabolites can be quantified in wastewater networks using wastewater-based epidemiology (WBE) methods. Standard WBE methods focus on samples collected at wastewater treatment plants (WWTPs). However, these methods do not capture more labile classes of metabolites such as glucuronide conjugates, products of the major phase II metabolic pathway for drug elimination. By shifting sample collection more upstream, these unambiguous markers of human exposure are captured before hydrolysis in the wastewater network. In this paper, we present an HPLC-MS/MS method that quantifies 8 glucuronide conjugates in addition to 31 parent and other metabolites of prescription and synthetic opioids, overdose treatment drugs, illicit drugs, and population markers. Calibration curves for all analytes are linear (r2 〉 0.98), except THC (r2 = 0.97), and in the targeted range (0.1–1,000 ng mL−1) with lower limits of quantification (S/N = 9) ranging from 0.098 to 48.75 ng mL−1. This method is fast with an injection-to-injection time of 7.5 min. We demonstrate the application of the method to five wastewater samples collected from a manhole in a city in eastern Massachusetts. Collected wastewater samples were filtered and extracted via solid-phase extraction (SPE). The SPE cartridges are eluted and concentrated in the laboratory via nitrogen-drying. The method and case study presented here demonstrate the potential and application of expanding WBE to monitoring labile metabolites in upstream wastewater

Description: This work was supported by the National Institute on Drug Abuse of the National Institutes of Health award number R44DA051106 to MM and PC. TE, PC and MM are funded by research grants from the Massachusetts Consortium on Pathogen Readiness and NIH R44DA051106. PRC is funded by NIH K23DA044874, independent research grants from e-ink corporation and Hans and Mavis Lopater Psychosocial Foundation.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Clemens, S. C., Yamamoto, M., Thirumalai, K., Giosan, L., Richey, J. N., Nilsson-Kerr, K., Rosenthal, Y., Anand, P., & McGrath, S. M. Remote and local drivers of Pleistocene South Asian summer monsoon precipitation: a test for future predictions. Science Advances, 7(23), (2021): eabg3848, https://doi.org/10.1126/sciadv.abg3848.

Description: South Asian precipitation amount and extreme variability are predicted to increase due to thermodynamic effects of increased 21st-century greenhouse gases, accompanied by an increased supply of moisture from the southern hemisphere Indian Ocean. We reconstructed South Asian summer monsoon precipitation and runoff into the Bay of Bengal to assess the extent to which these factors also operated in the Pleistocene, a time of large-scale natural changes in carbon dioxide and ice volume. South Asian precipitation and runoff are strongly coherent with, and lag, atmospheric carbon dioxide changes at Earth’s orbital eccentricity, obliquity, and precession bands and are closely tied to cross-equatorial wind strength at the precession band. We find that the projected monsoon response to ongoing, rapid high-latitude ice melt and rising carbon dioxide levels is fully consistent with dynamics of the past 0.9 million years.

Description: S.C.C. and S.M.M. were supported by U.S. NSF OCE1634774. M.Y. was funded by JSPS grants JPMXS05R2900001 and 19H05595 and JAMSTEC Exp. 353 postcruise study. K.N.-K. and P.A. were supported by UK-IODP, Open University, and NERC (NE/L002493/1), K.T. was supported by the Technology and Research Initiative Fund, Arizona Board of Regents.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Clark, S., Hubbard, K. A., McGillicuddy Jr, D. J., Ralston, D. K., & Shankar, S. Investigating Pseudo-nitzschia australis introduction to the Gulf of Maine with observations and models. Continental Shelf Research, 228, (2021): 104493, https://doi.org/10.1016/j.csr.2021.104493.

Description: In 2016, an unprecedented Pseudo-nitzschia australis bloom in the Gulf of Maine led to the first shellfishery closures due to domoic acid in the region's history. In this paper, potential introduction routes of P. australis are explored through observations, a hydrodynamic model, and a Lagrangian particle tracking model. Based on particle tracking experiments, the most likely source of P. australis to the Gulf of Maine was the Scotian Shelf. However, in 2016, connectivity between the Scotian Shelf and the bloom region was not significantly different from the other years between 2012 and 2019, nor were temperature conditions more favorable for P. australis growth. Observations indicated changes on the Scotian Shelf in 2016 preceded the introduction of P. australis: increased bottom salinity and decreased surface salinity. The increased bottom salinity on the shelf may be linked to anomalously saline water observed near the coast of Maine in 2016 via transport through Northeast Channel. The changes in upstream water mass properties may be related to the introduction of P. australis, and could be the result of either increased influence of the Labrador Current or increased outflow from the Gulf of St. Lawrence. The ultimate source of P. australis remains unknown, although the species has previously been observed in the eastern North Atlantic, and connectivity across the ocean is possible via a subpolar route. Continued and increased monitoring is warranted to track interannual Pseudo-nitzschia persistence in the Gulf of Maine, and sampling on the Scotian Shelf should be conducted to map upstream P. australis populations.

Description: This research was funded by the National Science Foundation (Grant Number OCE-1840381), the National Institute of Environmental Health Sciences (Grant Number 1P01ES028938), the Woods Hole Center for Oceans and Human Health, and the Academic Programs Office of the Woods Hole Oceanographic Institution.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Almayrac, M. G., Broadley, M. W., Bekaert, D. V., Hofmann, A., & Marty, B. Possible discontinuous evolution of atmospheric xenon suggested by Archean barites. Chemical Geology, 581, (2021): 120405, https://doi.org/10.1016/j.chemgeo.2021.120405.

Description: The Earth's atmosphere has continually evolved since its formation through interactions with the mantle as well as through loss of volatile species to space. Atmospheric xenon isotopes show a unique and progressive evolution during the Archean that stopped around the Archean-Proterozoic transition. The Xe isotope composition of the early atmosphere has been previously documented through the analysis of fluid inclusions trapped within quartz and barite. Whether this evolution was continuous or not is unclear, requiring additional analyses of ancient samples, which may potentially retain remnants of the ancient atmosphere. Here we present new argon, krypton and xenon isotopic data from a suite of Archean and Proterozoic barites ranging in age from 3.5 to 1.8 Ga, with the goal of providing further insights in to the evolution of atmospheric Xe, whilst also outlining the potential complications that can arise when using barites as a record of past atmospheres. Xenon released by low temperature pyrolysis and crushing of two samples which presumably formed around 2.8 and 2.6 Ga show Xe isotope mass dependent fractionation (MDF) of 11‰.u−1 and 3.4‰.u−1, respectively, relative to modern atmosphere. If trapped Xe is contemporaneous with the respective formation age, the significant difference in the degree of fractionation between the two samples provides supporting evidence for a plateau in the MDF-Xe evolution between 3.3 Ga and 2.8 Ga, followed by a rapid evolution at 2.8–2.6 Ga. This sharp decrease in MDF-Xe degree suggests the potential for a discontinuous temporal evolution of atmospheric Xe isotopes, which could have far reaching implications regarding current physical models of the early evolution of the Earth's atmosphere.

Description: This work was funded by the ERC grant No. 695618 to B.M. We thank the S.A.R.M for providing elemental bulk analyses of the barites. We thank Laurent Zimmerman for technical mentorship and assistance.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Karolyte, R., Barry, P. H., Hunt, A. G., Kulongoski, J. T., Tyne, R. L., Davis, T. A., Wright, M. T., McMahon, P. B., & Ballentine, C. J. Noble gas signatures constrain oil-field water as the carrier phase of hydrocarbons occurring in shallow aquifers in the San Joaquin Basin, USA. Chemical Geology, 584, (2021): 120491, https://doi.org/10.1016/j.chemgeo.2021.120491.

Description: Noble gases record fluid interactions in multiphase subsurface environments through fractionation processes during fluid equilibration. Water in the presence of hydrocarbons at the subsurface acquires a distinct elemental signature due to the difference in solubility between these two fluids. We find the atmospheric noble gas signature in produced water is partially preserved after hydrocarbons production and water disposal to unlined ponds at the surface. This signature is distinct from meteoric water and can be used to trace oil-field water seepage into groundwater aquifers. We analyse groundwater (n = 30) and fluid disposal pond (n = 2) samples from areas overlying or adjacent to the Fruitvale, Lost Hills, and South Belridge Oil Fields in the San Joaquin Basin, California, USA. Methane (2.8 × 10−7 to 3 × 10−2 cm3 STP/cm3) was detected in 27 of 30 groundwater samples. Using atmospheric noble gas signatures, the presence of oil-field water was identified in 3 samples, which had equilibrated with thermogenic hydrocarbons in the reservoir. Two (of the three) samples also had a shallow microbial methane component, acquired when produced water was deposited in a disposal pond at the surface. An additional 6 samples contained benzene and toluene, indicative of interaction with oil-field water; however, the noble gas signatures of these samples are not anomalous. Based on low tritium and 14C contents (≤ 0.3 TU and 0.87–6.9 pcm, respectively), the source of oil-field water is likely deep, which could include both anthropogenic and natural processes. Incorporating noble gas analytical techniques into the groundwater monitoring programme allows us to 1) differentiate between thermogenic and microbial hydrocarbon gas sources in instances when methane isotope data are unavailable, 2) identify the carrier phase of oil-field constituents in the aquifer (gas, oil-field water, or a combination), and 3) differentiate between leakage from a surface source (disposal ponds) and from the hydrocarbon reservoir (either along natural or anthropogenic pathways such as faulty wells).

Description: This work was supported by the U.S. Geological Survey as part of the California State Water Resources Control Board's Oil and Gas Regional Monitoring 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 Bandara, K., Varpe, O., Maps, F., Ji, R., Eiane, K., & Tverberg, V. Timing of Calanus finmarchicus diapause in stochastic environments. Ecological Modelling, 460, (2021): 109739, https://doi.org/10.1016/j.ecolmodel.2021.109739.

Description: In environments with strong seasonality, many herbivorous zooplankton remain active only during the productive season and undergo a period of inactivity and suppressed development termed ‘diapause’ during the unproductive season. The ability to time the diapause entry and exit in response to the seasonality of the environment is thus essential for their survival. However, timing of diapause may become challenging when environmental conditions vary stochastically across shorter and longer timescales, and particularly when zooplankton lack external cues to predict these variations. In this study, we used a novel individual-based model to study the emerging patterns of diapause timing of the high-latitude marine herbivorous copepod Calanus finmarchicus under shorter- (6-h) and longer-term (interannual) environmental stochasticity. The model simulated growth, development, survival and reproduction (income breeding) of a C. finmarchicus population over multiple calendar years and traced the emergence of behavioral responses and life history strategies. The emergent timing of diapause entry and exit were robust to shorter-term environmental stochasticity, which was manifested through morphological (i.e., body and energy reserve sizes) and behavioral plasticity (i.e., diel vertical migration). Longer-term stochastic variations of temperature and food environments altered the timing of diapause entry, which occurred earlier in warmer years with higher growth potential and vice versa. Irrespective of the modelled environmental variability, diapause exit occurred asynchronously throughout the year. This appeared to be a consequence of a diversified bet hedging strategy, where parents spread the starvation mortality risk of ascending to the upper pelagial at food-deprived times of the year among their offspring. This was a potent strategy, particularly in simulations where the timing of the algal bloom varied stochastically between years, since a fraction of the population was present in the upper pelagial year-round and those that coincided with the emergence of the pelagic primary production survived and produced the next generation.

Description: This work was funded by the project GLIDER, financed by The Research Council of Norway Demo2000 and ConocoPhillips Norge (Grant no. 269188/E30).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Loranger, S., Pedersen, G., & Blomberg, A. E. A. A model for the fate of carbon dioxide from a simulated carbon storage seep. International Journal of Greenhouse Gas Control, 107, (2021): 103293, https://doi.org/10.1016/j.ijggc.2021.103293.

Description: Offshore geological carbon storage (GCS) is a rapidly developing technology essential for meeting international climate goals. While the likelihood of leakage from a properly planned geological sequestration site is low, assurance that CO stays contained will require robust monitoring programs. While seismic imaging methods are used to monitor the geological reservoir, the ideal method for monitoring the water column above the reservoir depends on the fate and transport of CO. Whether CO is likely to be present as a rising seep of bubbles or dissolved in the water column near the seafloor will determine the appropriate monitoring technology and lead to a better understanding of the environmental impact of a potential leak. In this study, high definition video of a laboratory release of a carbon dioxide bubble seep recorded the size distribution of bubbles as a function of flow rate and orifice diameter. The transport of CO from different bubble size distributions was then modeled using the Texas A&M Oil Spill Calculator modeling suite. Model results show that the most important factor determining the rise height and transport of CO from the simulated leak was the maximum initial bubble size. For a maximum bubble radius of 5 mm, 95% of CO in the simulated seep reached a height of 17.1 m above the seafloor. When the maximum bubble radius was limited to 3 mm, 95% of CO dissolved by 7.8 m above the seafloor. The modeled results were verified during a controlled release of CO in Oslo Fjord.

Description: This work was carried out as part of the ACT4storage project (617334) funded by Gassnova and Norwegian industry partners through the CLIMIT programme.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Seltzer, A. M., Bekaert, D. V., Barry, P. H., Durkin, K. E., Mace, E. K., Aalseth, C. E., Zappala, J. C., Mueller, P., Jurgens, B., & Kulongoski, J. T. Groundwater residence time estimates obscured by anthropogenic carbonate. Science Advances, 7(17), (2021): eabf3503, https://doi.org/10.1126/sciadv.abf3503.

Description: Groundwater is an important source of drinking and irrigation water. Dating groundwater informs its vulnerability to contamination and aids in calibrating flow models. Here, we report measurements of multiple age tracers (14C, 3H, 39Ar, and 85Kr) and parameters relevant to dissolved inorganic carbon (DIC) from 17 wells in California’s San Joaquin Valley (SJV), an agricultural region that is heavily reliant on groundwater. We find evidence for a major mid-20th century shift in groundwater DIC input from mostly closed- to mostly open-system carbonate dissolution, which we suggest is driven by input of anthropogenic carbonate soil amendments. Crucially, enhanced open-system dissolution, in which DIC equilibrates with soil CO2, fundamentally affects the initial 14C activity of recently recharged groundwater. Conventional 14C dating of deeper SJV groundwater, assuming an open system, substantially overestimates residence time and thereby underestimates susceptibility to modern contamination. Because carbonate soil amendments are ubiquitous, other groundwater-reliant agricultural regions may be similarly affected.

Description: his work was conducted as a part of the USGS National Water Quality Assessment Program (NAWQA) Enhanced Trends Project (https://water.usgs.gov/nawqa/studies/gwtrends/). Measurements at Argonne National Laboratory were supported by Department of Energy, Office of Science under contract DE-AC02-06CH11357. Measurements at Pacific Northwest National Laboratory were part of the Ultra-Sensitive Nuclear Measurements Initiative conducted under the Laboratory Directed Research and Development Program. PNNL is operated by Battelle for the U.S. Department of Energy under Contract DE-AC05-76RL01830. This work was also partially supported by NSF award OCE-1923915 (to A.M.S. and P.H.B. at WHOI).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Vera, J., & Lippmann, K. Post-stroke epileptogenesis is associated with altered intrinsic properties of hippocampal pyramidal neurons leading to increased theta resonance. Neurobiology of Disease, (2021): 105425, https://doi.org/10.1016/j.nbd.2021.105425.

Description: Brain insults like stroke, trauma or infections often lead to blood-brain barrier-dysfunction (BBBd) frequently resulting into epileptogenesis. Affected patients suffer from seizures and cognitive comorbidities that are potentially linked to altered network oscillations. It has been shown that a hippocampal BBBd in rats leads to in vivo seizures and increased power at theta (3–8 Hz), an important type of network oscillations. However, the underlying cellular mechanisms remain poorly understood. At membrane potentials close to the threshold for action potentials (APs) a subpopulation of CA1 pyramidal cells (PCs) displays intrinsic resonant properties due to an interplay of the muscarine-sensitive K+-current (IM) and the persistent Na+-current (INaP). Such resonant neurons are more excitable and generate more APs when stimulated at theta frequencies, being strong candidates for contributing to hippocampal theta oscillations during epileptogenesis. We tested this hypothesis by characterizing changes in intrinsic properties of hippocampal PCs one week after post-stroke epileptogenesis, a model associated with BBBd, using slice electrophysiology and computer modeling. We find a higher proportion of resonant neurons in BBBd compared to sham animals (47 vs. 29%), accompanied by an increase in their excitability. In contrast, BBBd non-resonant neurons showed a reduced excitability, presented with lower impedance and more positive AP threshold. We identify an increase in IM combined with either a reduction in INaP or an increase in ILeak as possible mechanisms underlying the observed changes. Our results support the hypothesis that a higher proportion of more excitable resonant neurons in the hippocampus contributes to increased theta oscillations and an increased likelihood of seizures in a model of post-stroke epileptogenesis.

Description: This work was supported by the Grass Foundation (MD, USA) [Grass Fellowship to Jorge Vera and Kristina Lippmann in 2017].

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Wehmiller, J. F., Brothers, L. L., Ramsey, K. W., Foster, D. S., Mattheus, C. R., Hein, C. J., & Shawler, J. L. Molluscan aminostratigraphy of the US Mid-Atlantic Quaternary coastal system: implications for onshore-offshore correlation, paleochannel and barrier island evolution, and local late Quaternary sea-level history. Quaternary Geochronology, 66, (2021): 101177, https://doi.org/10.1016/j.quageo.2021.101177.

Description: The Quaternary record of the US Mid-Atlantic coastal system includes onshore emergent late Pleistocene shoreline deposits, offshore inner shelf and barrier island units, and paleovalleys formed during multiple glacial stage sea-level lowstands. The geochronology of this coastal system is based on uranium series, radiocarbon, amino acid racemization (AAR), and optically stimulated luminescence (OSL) methods. We report over 600 mollusk AAR results from 93 sites between northeastern North Carolina and the central New Jersey shelf, representing samples from both onshore cores or outcrops, sub-barrier and offshore cores, and transported shells from barrier island beaches. AAR age estimates are constrained by paired 14C analyses on specific shells and associated U-series coral ages from onshore sites. AAR data from offshore cores are interpreted in the context of detailed seismic stratigraphy. The distribution of Pleistocene-age shells on the island beaches is linked to the distribution of inner shelf or sub-barrier source units. Age mixing over a range of time-scales (~1 ka to ~100 ka) is identified by AAR results from onshore, beach, and shelf collections, often contributing insights into the processes forming individual barrier islands. The regional aminostratigraphic framework identifies a widespread late Pleistocene (Marine Isotope Stage 5) aminozone, with isolated records of middle and early Pleistocene deposition. AAR results provide age estimates for the timing of formation of the three major paleochannels that underlie the Delmarva Peninsula: Persimmon Point paleochannel ≥800 ka; Exmore paleochannel ~400–500 ka (MIS 12); and Eastville paleochannel 〉 125 ka (MIS 6). The results demonstrate the value of synthesizing abundant AAR chronologic data across various coastal environments, integrating multiple distinct geologic studies. The ages and elevations of the Quaternary units are important for current hypotheses about relative sea-level history and crustal dynamics in the region, which was likely influenced by the Laurentide ice sheet, the margin just ~400 km to the north.

Description: This project was funded through a cooperative agreement with the Bureau of Ocean Energy Management of the U.S. Department of the Interior, Offshore Sand Resources for Coastal Resilience and Restoration Planning: M14AC00003 and M16AC00001. We thank J. Waldner (BOEM) for support and encouragement during this project. We also thank S. Howard and K. Luciano, South Carolina Geological Survey, and numerous colleagues in both the Mid-Atlantic and Southeast Atlantic BOEM ASAP projects, active from 2015 through 2019. This paper is contribution #3999 of the Virginia Institute of Marine Science, William & Mary. Partial support was also provided to Hein by the Mid-Atlantic Sea Grant program (NOAA) award numbers R/71856G and R/71856H and a Virginia Sea Grant (NOAA) Fellowship award NA18OAR4170083 supported Shawler. JFW acknowledges support from the University of Delaware Retired Faculty Research 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 Grabon, J. S., Toole, J. M., Nguyen, A. T., & Krishfield, R. A. An analysis of Atlantic water in the Arctic Ocean using the Arctic subpolar gyre state estimate and observations. Progress in Oceanography, 198, (2021): 102685, https://doi.org/10.1016/j.pocean.2021.102685.

Description: The Atlantic Water (AW) Layer in the Arctic Subpolar gyre sTate Estimate Release 1 (ASTE R1), a data-constrained, regional, medium-resolution coupled ocean-sea ice model, is analyzed for the period 2004–2017 in combination with available hydrographic data. The study, focusing on AW defined as the waters between two bounding isopycnals, examines the time-average, mean seasonal cycle and interannual variability of AW Layer properties and circulation. A surge of AW, marked by rapid increases in mean AW Layer potential temperature and AW Layer thickness, begins two years into the state estimate and traverses the Arctic Ocean along boundary current pathways at a speed of 1–2 cm/s. The surge also alters AW circulation, including a reversal in flow direction along the Lomonosov Ridge, resulting in a new quasi-steady AW circulation from 2010 through the end of the state estimate period. The time-mean AW circulation during this latter time period indicates that a significant amount of AW spreads over the Lomonosov Ridge rather than directly returning along the ridge to Fram Strait. A three-layer depiction of the time-averaged ASTE R1 overturning circulation within the Arctic Ocean reveals that more AW is converted to colder, fresher Surface Layer water than is transformed to Deep and Bottom Water (1.2 Sv vs. 0.4 Sv). ASTE R1 also exhibits an increase in the volume of AW over the study period at a rate of 1.4 Sv, with near compensating decrease in Deep and Bottom Water volume. Observed AW properties compared to ASTE R1 output reveal increasing misfit during the simulated period with the ASTE R1 AW Layer generally being warmer and thicker than in observations.

Description: This work is based on the dissertation of the lead author submitted in partial requirement of a M.S. degree from the Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program in Oceanography. The lead author’s participation was funded by the United States Navy’s Civilian Institution (CIVINS) Program. The contributions to this study by the junior authors were supported by the National Science Foundation (JMT and RAK grant PLR-1603660; ATN grant NSF-OPP-1603903).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tarrant, A. M., McNamara-Bordewick, N., Blanco-Bercial, L., Miccoli, A., & Maas, A. E. Diel metabolic patterns in a migratory oceanic copepod. Journal of Experimental Marine Biology and Ecology, 545, (2021): 151643, https://doi.org/10.1016/j.jembe.2021.151643.

Description: Diel vertical migration of zooplankton profoundly impacts the transport of nutrients and carbon through the water column. Despite the acknowledged importance of this active flux to ocean biogeochemistry, these contributions remain poorly constrained, in part because daily variations in metabolic rates are not considered or are modeled as simple functions of temperature. To address this uncertainty, we sampled the subtropical copepod Pleuromamma xiphias at 4- to 7-h intervals throughout the daily migration and measured rates of oxygen consumption, ammonium excretion, fecal pellet production and metabolic enzyme activity. No significant patterns were detected in rates of oxygen consumption or ammonium excretion for freshly caught animals over the diel cycle. Fecal pellet production was highest during mid-night, consistent with several hours of feeding near the surface. Surface feeding resulted in fecal pellet production at depth in the morning, providing direct evidence that active flux of particulate organic carbon occurs in this region. Electron transport system activity was highest during the afternoon, contrary to our prediction of reduced daytime metabolism. Activity of both glutamate dehydrogenase and citrate synthase increased during early night, reflecting higher capacity for excretion and aerobic respiration, respectively. Overall, these results show that activities of metabolic enzymes vary during diel vertical migration. The surprising observation of elevated afternoon enzyme activity coupled with daytime fecal pellet and ammonium production suggests that additional characterization of the daytime activity of migratory zooplankton is warranted.

Description: This work was supported by the National Science Foundation [Grants OCE-1829318 to AEMand LBB, and OCE-1829378 to AMT]. Support for NM-B was provided by the Woods Hole Oceanographic Institution's Summer Student Fellows 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 Angulo, E., Diagne, C., Ballesteros-Mejia, L., Adamjy, T., Ahmed, D. A., Akulov, E., Banerjee, A. K., Capinha, C., Dia, C. A. K. M., Dobigny, G., Duboscq-Carra, V. G., Golivets, M., Haubrock, P. J., Heringer, G., Kirichenko, N., Kourantidou, M., Liu, C., Nuñez, M. A., Renault, D., Roiz, D., Taheri, A., Verbrugge, L. N. H., Watari, Y., Xiong, W., & Courchamp, F. Non-English languages enrich scientific knowledge: the example of economic costs of biological invasions. Science of the Total Environment, 775, (2021): 144441, https://doi.org/10.1016/j.scitotenv.2020.144441.

Description: We contend that the exclusive focus on the English language in scientific research might hinder effective communication between scientists and practitioners or policy makers whose mother tongue is non-English. This barrier in scientific knowledge and data transfer likely leads to significant knowledge gaps and may create biases when providing global patterns in many fields of science. To demonstrate this, we compiled data on the global economic costs of invasive alien species reported in 15 non-English languages. We compared it with equivalent data from English documents (i.e., the InvaCost database, the most up-to-date repository of invasion costs globally). The comparison of both databases (~7500 entries in total) revealed that non-English sources: (i) capture a greater amount of data than English sources alone (2500 vs. 2396 cost entries respectively); (ii) add 249 invasive species and 15 countries to those reported by English literature, and (iii) increase the global cost estimate of invasions by 16.6% (i.e., US$ 214 billion added to 1.288 trillion estimated from the English database). Additionally, 2712 cost entries — not directly comparable to the English database — were directly obtained from practitioners, revealing the value of communication between scientists and practitioners. Moreover, we demonstrated how gaps caused by overlooking non-English data resulted in significant biases in the distribution of costs across space, taxonomic groups, types of cost, and impacted sectors. Specifically, costs from Europe, at the local scale, and particularly pertaining to management, were largely under-represented in the English database. Thus, combining scientific data from English and non-English sources proves fundamental and enhances data completeness. Considering non-English sources helps alleviate biases in understanding invasion costs at a global scale. Finally, it also holds strong potential for improving management performance, coordination among experts (scientists and practitioners), and collaborative actions across countries. Note: non-English versions of the abstract and figures are provided in Appendix S5 in 12 languages.

Description: This work was supported by the French National Research Agency (ANR-14-CE02-0021) and the BNP-Paribas Foundation Climate Initiative for the InvaCost project that allowed the construction of the InvaCost database; the AXA Research Fund Chair of Invasion Biology of University Paris Saclay (EA and LBM contracts) and BiodivERsA and Belmont-Forum call 2018 on biodiversity scenarios – “Alien Scenarios” (the workshop where this work was initiated, and MG and CD contracts, BMBF/PT DLR 01LC1807C); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (Capes) (Finance code 001, GH contract); Russian Foundation for Basic Research (grant number 19-04-01028-a); InEE-CNRS who supports the network GdR 3647 ‘Invasions Biologiques’, the French Polar Institute Paul-Emile Victor (Project IPEV 136 ‘Subanteco’), and the national nature reserve of the French southern lands (RN-TAF); Portuguese National Funds through Fundação para a Ciência e a Tecnologia (grant numbers CEECIND/02037/2017; UIDB/00295/2020 and UIDP/00295/2020); Kuwait Foundation for the Advancement of Sciences (KFAS) (grant number PR1914SM-01) and the Gulf University for Science and Technology (GUST) internal seed fund (grant number 187092).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cuthbert, R. N., Pattison, Z., Taylor, N. G., Verbrugge, L., Diagne, C., Ahmed, D. A., Leroy, B., Angulo, E., Briski, E., Capinha, C., Catford, J. A., Dalu, T., Essl, F., Gozlan, R. E., Haubrock, P. J., Kourantidou, M., Kramer, A. M., Renault, D., Wasserman, R. J., & Courchamp, F. Global economic costs of aquatic invasive alien species. Science of the Total Environment, 775, (2021): 145238, https://doi.org/10.1016/j.scitotenv.2021.145238.

Description: Much research effort has been invested in understanding ecological impacts of invasive alien species (IAS) across ecosystems and taxonomic groups, but empirical studies about economic effects lack synthesis. Using a comprehensive global database, we determine patterns and trends in economic costs of aquatic IAS by examining: (i) the distribution of these costs across taxa, geographic regions and cost types; (ii) the temporal dynamics of global costs; and (iii) knowledge gaps, especially compared to terrestrial IAS. Based on the costs recorded from the existing literature, the global cost of aquatic IAS conservatively summed to US$345 billion, with the majority attributed to invertebrates (62%), followed by vertebrates (28%), then plants (6%). The largest costs were reported in North America (48%) and Asia (13%), and were principally a result of resource damages (74%); only 6% of recorded costs were from management. The magnitude and number of reported costs were highest in the United States of America and for semi-aquatic taxa. Many countries and known aquatic alien species had no reported costs, especially in Africa and Asia. Accordingly, a network analysis revealed limited connectivity among countries, indicating disparate cost reporting. Aquatic IAS costs have increased in recent decades by several orders of magnitude, reaching at least US$23 billion in 2020. Costs are likely considerably underrepresented compared to terrestrial IAS; only 5% of reported costs were from aquatic species, despite 26% of known invaders being aquatic. Additionally, only 1% of aquatic invasion costs were from marine species. Costs of aquatic IAS are thus substantial, but likely underreported. Costs have increased over time and are expected to continue rising with future invasions. We urge increased and improved cost reporting by managers, practitioners and researchers to reduce knowledge gaps. Few costs are proactive investments; increased management spending is urgently needed to prevent and limit current and future aquatic IAS damages.

Description: The authors acknowledge the French National Research Agency (ANR-14-CE02-0021) and the BNP-Paribas Foundation Climate Initiative for funding the InvaCost project that allowed the construction of the InvaCost database. The present work was conducted following a workshop funded by the AXA Research Fund Chair of Invasion Biology and is part of the AlienScenarios project funded by BiodivERsA and Belmont-Forum call 2018 on biodiversity scenarios. RNC is funded through a Humboldt Research Fellowship from the Alexander von Humboldt Foundation. DAA is funded by the Kuwait Foundation for the Advancement of Sciences (KFAS) (PR1914SM-01) and the Gulf University for Science and Technology (GUST) internal seed fund (187092). CD was funded by the BiodivERsA-Belmont Forum Project AlienScenarios (BMBF/PT DLR 01LC1807C). EA was funded by the AXA Research Fund Chair of Invasion Biology of University Paris Saclay. CC was supported by Portuguese National Funds through Fundação para a Ciência e a Tecnologia (CEECIND/02037/2017; UIDB/00295/2020 and UIDP/00295/2020). TD acknowledges funding from National Research Foundation (NRF_ZA) (Grant Number: 117700). FE appreciates funding by the Austrian Science Foundation (FWF project no I 4011-B32). AMK was supported by the NSF Macrosystems Biology program under grant 1834548. DR thanks InEE-CNRS who supports the French national network Biological Invasions (Groupement de Recherche InvaBio, 2014–2022).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Rypina, I. I., Dotzel, M. M., Pratt, L. J., Hernandez, C. M., & Llopiz, J. K. Exploring interannual variability in potential spawning habitat for Atlantic bluefin tuna in the Slope Sea. Progress in Oceanography, 192, (2021): 102514, https://doi.org/10.1016/j.pocean.2021.102514.

Description: The Slope Sea in the Northwest Atlantic Ocean, located between the Gulf Stream and the continental shelf of the Northeast United States, is a recently-documented possible major spawning ground for Atlantic bluefin tuna (Thunnus thynnus). Larval surveys and a habitat modeling study have shown that suitable spawning habitat occurs in the Slope Sea, but the degree to which this habitat varies interannually is an open question. Here, we perform a decade-long (2009–2018) numerical modeling analysis, with simulated larvae released uniformly throughout the Slope Sea, to investigate the interannual variability in the water temperature and circulation criteria deemed necessary for successful spawning. We also quantify the influence of Gulf Stream meanders and overshoot events on larval retention and their effect on habitat suitability rates throughout the Slope Sea, defined as the percentage of simulated larvae released at a given location that satisfy criteria related to water temperature and retention near nursery habitat. Average environmental oceanographic conditions over the decade are most favorable in the western part of the Slope Sea, specifically in the Slope Gyre and away from the immediate vicinity of the Gulf Stream. Variability in domain- and summertime-averaged yearly spawning habitat suitability rates is up to 25% of the mean decadal-averaged values. Yearly habitat suitability correlates strongly with the Gulf Stream overshoot but does not correlate well with other oceanographic variables or indices, so an overshoot index can be used as a sole oceanographic proxy for predicting yearly bluefin spawning habitat suitability in the Slope Sea. Selective spawning can weaken the correlation between habitat suitability and Gulf Stream overshoot. Effort should be put towards collecting observational data against which we could validate our findings.

Description: This work was funded by a US National Science Foundation (NSF) grant (OCE-1558806) awarded to IIR, LJP, and JKL. MMD was supported by an NSF Graduate Research Fellowship. CMH was partially supported by the Adelaide and Charles Link Foundation and the J. Seward Johnson Endowment in support of the Woods Hole Oceanographic Institution’s Marine Policy Center.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Trembath-Reichert, E., Shah Walter, S. R., Ortiz, M. A. F., Carter, P. D., Girguis, P. R., & Huber, J. A. Multiple carbon incorporation strategies support microbial survival in cold subseafloor crustal fluids. Science Advances, 7(18), (2021): eabg0153, https://doi.org/10.1126/sciadv.abg0153.

Description: Biogeochemical processes occurring in fluids that permeate oceanic crust make measurable contributions to the marine carbon cycle, but quantitative assessments of microbial impacts on this vast, subsurface carbon pool are lacking. We provide bulk and single-cell estimates of microbial biomass production from carbon and nitrogen substrates in cool, oxic basement fluids from the western flank of the Mid-Atlantic Ridge. The wide range in carbon and nitrogen incorporation rates indicates a microbial community well poised for dynamic conditions, potentially anabolizing carbon and nitrogen at rates ranging from those observed in subsurface sediments to those found in on-axis hydrothermal vent environments. Bicarbonate incorporation rates were highest where fluids are most isolated from recharging bottom seawater, suggesting that anabolism of inorganic carbon may be a potential strategy for supplementing the ancient and recalcitrant dissolved organic carbon that is prevalent in the globally distributed subseafloor crustal environment.

Description: The Gordon and Betty Moore Foundation sponsored most of the observatory components at North Pond through grant GBMF1609. This work was supported by the National Science Foundation through grants NSF OCE-1745589, OCE-1635208, and OCE-1062006 to J.A.H. and NSF OCE-1635365 to P.R.G. and S.R.S.W.; NASA Postdoctoral Fellowship with the NASA Astrobiology Institute to E.T.-R.; L’Oréal USA For Women in Science Fellowship to E.T.-R.; and Woods Hole Partnership Education Program, sponsored by the Woods Hole Diversity Initiative to M.A.F.O. The Center for Dark Energy Biosphere Investigations (C-DEBI OCE-0939564) also supported the participation of J.A.H. and P.D.C. This is C-DEBI contribution number 564.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Mazurkiewicz, M., Meyer-Kaiser, K., Sweetman, A. K., Renaud, P. E., & Wlodarska-Kowalczuk, M. Megabenthic standing stocks and organic carbon demand in a warming Arctic. Progress in Oceanography, 196, (2021): 102616, https://doi.org/10.1016/j.pocean.2021.102616.

Description: Benthic megafauna (organisms large enough to be visible on seabed photographs) are regarded as important for carbon cycling in benthic habitats. They are a food source for many predators like fish and marine mammals and may stimulate carbon mineralization in sediment by bioturbation. However, few studies address these basic characteristics of megabenthos quantitatively. This study quantifies the spatial variability in standing stock (biomass) and functioning (secondary production, respiration and carbon demand) of benthic megafauna in fjords and on the continental shelf of Svalbard. Organisms were measured from sea bottom images to assess their biomass using length-weight relationships and volumetric methods, then respiration and production were estimated with empirical artificial neural network models. Significantly higher standing stock, secondary production, respiration, and carbon demand were found in fjords categorized as ‘cold’ (as defined by water temperature, prevailing water masses and ice-cover) than in the ‘warm’ ones. Cold fjords were dominated by Echinodermata, while in warm fjords Crustacea prevailed. All megafaunal community parameters were negatively correlated with bottom temperature. It was not possible to assess specific direct impacts of temperature, and indirect effects may be more relevant to our findings. These include temperature-driven changes in primary production, ice cover and ice-algae production or predation pressure from carnivores expanding their ranges northward. The progression of climate warming may affect megafaunal communities by reducing their biomass, production, and carbon demand and have profound effects on ecosystem functioning.

Description: Financing was provided by the University Centre in Svalbard and Akvaplan-niva (to PER), by the National Science Centre grant number UMO-2016/23/B/NZ8/02410 (AbeFun), and statutory funds of the Institute of Oceanology, Polish Academy of Sciences (to MWK).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scarlett, A. G., Nelson, R. K., Gagnon, M. M., Holman, A. I., Reddy, C. M., Sutton, P. A., & Grice, K. MV Wakashio grounding incident in Mauritius 2020: the world’s first major spillage of very low sulfur fuel oil. Marine Pollution Bulletin, 171, (2021): 112917, https://doi.org/10.1016/j.marpolbul.2021.112917.

Description: Very Low Sulfur Fuel Oils (VSLFO, 〈0.5% S) are a new class of marine fuel oils, introduced to meet recent International Maritime Organization regulations. The MV Wakashio was reported to have released 1000 t of VLSFO when it grounded on a reef in Mauritius on 25th July 2020. A field sample of oily residue contaminating the Mauritian coast was collected on 16th August 2020 and compared with the Wakashio fuel oil. Both oils were analyzed for organic and elemental content, and stable isotope ratios δ13C and δ2H measured. Comprehensive two-dimensional gas chromatography with high-resolution mass spectrometry was used to identify and compare biomarkers resistant to weathering. The aromatic content in the VLSFO was relatively low suggesting that the potential for ecosystem harm arising from exposure to toxic components may be less than with traditional fuel oil spills. The Wakashio oil spill is, to our knowledge, the first documented spill involving VLSFO.

Description: The project at Curtin University was supported by the Australian Research Council (grant numbers LP170101000, LE110100119 and LE130100145. CMR and RKN were supported by the National Science Foundation (OCE-1634478 and OCE-1756242). GC × GC analysis support provided by WHOI's Investment in Science Fund.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Johnson, A. C., Ostrander, C. M., Romaniello, S. J., Reinhard, C. T., Greaney, A. T., Lyons, T. W., & Anbar, A. D. Reconciling evidence of oxidative weathering and atmospheric anoxia on Archean Earth. Science Advances, 7(40), (2021): eabj0108, https://doi.org/10.1126/sciadv.abj0108.

Description: Evidence continues to emerge for the production and low-level accumulation of molecular oxygen (O2) at Earth’s surface before the Great Oxidation Event. Quantifying this early O2 has proven difficult. Here, we use the distribution and isotopic composition of molybdenum in the ancient sedimentary record to quantify Archean Mo cycling, which allows us to calculate lower limits for atmospheric O2 partial pressures (PO2) and O2 production fluxes during the Archean. We consider two end-member scenarios. First, if O2 was evenly distributed throughout the atmosphere, then PO2 〉 10–6.9 present atmospheric level was required for large periods of time during the Archean eon. Alternatively, if O2 accumulation was instead spatially restricted (e.g., occurring only near the sites of O2 production), then O2 production fluxes 〉0.01 Tmol O2/year were required. Archean O2 levels were vanishingly low according to our calculations but substantially above those predicted for an abiotic Earth system.

Description: We would like to thank our funding sources, including FESD “Dynamics of Earth System Oxygenation” (NSF EAR 1338810 to A.D.A.), NASA Earth and Space Science Fellowship awarded to A.C.J. (80NSSC17K0498), NSF EAR PF to A.C.J. (1952809), and WHOI Postdoctoral Fellowship to C.M.O. C.T.R. acknowledges support from the NASA Astrobiology Institute. We also acknowledge support from the Metal Utilization and Selection across Eons (MUSE) Interdisciplinary Consortium for Astrobiology Research, sponsored by the National Aeronautics and Space Administration Science Mission Directorate (19-ICAR19_2-0007).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bekaert, D. V., Auro, M., Shollenberger, Q. R., Liu, M.-C., Marschall, H., Burton, K. W., Jacobsen, B., Brennecka, G. A., McPherson, G. J., von Mutius, R., Sarafian, A., & Nielsen, S. G. Fossil records of early solar irradiation and cosmolocation of the CAI factory: a reappraisal. Science Advances, 7(40), (2021): eabg8329, https://doi.org/10.1126/sciadv.abg8329.

Description: Calcium-aluminum–rich inclusions (CAIs) in meteorites carry crucial information about the environmental conditions of the nascent Solar System prior to planet formation. Based on models of 50V–10Be co-production by in-situ irradiation, CAIs are considered to have formed within ~0.1 AU from the proto-Sun. Here, we present vanadium (V) and strontium (Sr) isotopic co-variations in fine- and coarse-grained CAIs and demonstrate that kinetic isotope effects during partial condensation and evaporation best explain V isotope anomalies previously attributed to solar particle irradiation. We also report initial excesses of 10Be and argue that CV CAIs possess essentially a homogeneous level of 10Be, inherited during their formation. Based on numerical modeling of 50V–10Be co-production by irradiation, we show that CAI formation during protoplanetary disk build-up likely occurred at greater heliocentric distances than previously considered, up to planet-forming regions (~1AU), where solar particle fluxes were sufficiently low to avoid substantial in-situ irradiation of CAIs.

Description: This study was funded by NASA Emerging Worlds grant NNX16AD36G to S.G.N. and prepared by LLNL under contract DE-AC52-07NA27344 with release number LLNL-JRNL-819045. M.C.L acknowledges the support by the NASA grant 80NSSC20K0759. The UCLA ion microprobe facility is partially supported by a grant from the NSF Instrumentation and Facilities program.

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Leech, V., Hazel, J. W., Gatlin, J. C., Lindsay, A. E., & Manhart, A. Mathematical modeling accurately predicts the dynamics and scaling of nuclear growth in discrete cytoplasmic volumes. Journal of Theoretical Biology, 533, (2022): 110936, https://doi.org/10.1016/j.jtbi.2021.110936.

Description: Scaling of nuclear size with cell size has been observed in many species and cell types. In this work we formulate a modeling framework based on the limiting component hypothesis. We derive a family of spatio-temporal mathematical models for nuclear size determination based on different transport and growth mechanisms. We analyse model properties and use in vitro experimental data to identify the most probable mechanism. This suggests that nuclear volume scales with cell volume and that a nucleus controls its import rate as it grows. We further test the model by comparing to data of early frog development, where rapid cell divisions set the relevant time scales.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tyne, R. L., Barry, P. H., Karolyte, R., Byrne, D. J., Kulongoski, J. T., Hillegonds, D. J., & Ballentine, C. J. Investigating the effect of enhanced oil recovery on the noble gas signature of casing gases and produced waters from selected California oil fields. Chemical Geology, 584, (2021): 120540. https://doi.org/10.1016/j.chemgeo.2021.120540.

Description: In regions where water resources are scarce and in high demand, it is important to safeguard against contamination of groundwater aquifers by oil-field fluids (water, gas, oil). In this context, the geochemical characterisation of these fluids is critical so that anthropogenic contaminants can be readily identified. The first step is characterising pre-development geochemical fluid signatures (i.e., those unmodified by hydrocarbon resource development) and understanding how these signatures may have been perturbed by resource production, particularly in the context of enhanced oil recovery (EOR) techniques. Here, we present noble gas isotope data in fluids produced from oil wells in several water-stressed regions in California, USA, where EOR is prevalent. In oil-field systems, only casing gases are typically collected and measured for their noble gas compositions, even when oil and/or water phases are present, due to the relative ease of gas analyses. However, this approach relies on a number of assumptions (e.g., equilibrium between phases, water-to-oil ratio (WOR) and gas-to-oil ratio (GOR) in order to reconstruct the multiphase subsurface compositions. Here, we adopt a novel, more rigorous approach, and measure noble gases in both casing gas and produced fluid (oil-water-gas mixtures) samples from the Lost Hills, Fruitvale, North and South Belridge (San Joaquin Basin, SJB) and Orcutt (Santa Maria Basin) Oil Fields. Using this method, we are able to fully characterise the distribution of noble gases within a multiphase hydrocarbon system. We find that measured concentrations in the casing gases agree with those in the gas phase in the produced fluids and thus the two sample types can be used essentially interchangeably. EOR signatures can readily be identified by their distinct air-derived noble gas elemental ratios (e.g., 20Ne/36Ar), which are elevated compared to pre-development oil-field fluids, and conspicuously trend towards air values with respect to elemental ratios and overall concentrations. We reconstruct reservoir 20Ne/36Ar values using both casing gas and produced fluids and show that noble gas ratios in the reservoir are strongly correlated (r2 = 0.88–0.98) to the amount of water injected within ~500 m of a well. We suggest that the 20Ne/36Ar increase resulting from injection is sensitive to the volume of fluid interacting with the injectate, the effective water-to-oil ratio, and the composition of the injectate. Defining both the pre-development and injection-modified hydrocarbon reservoir compositions are crucial for distinguishing the sources of hydrocarbons observed in proximal groundwaters, and for quantifying the transport mechanisms controlling this occurrence.

Description: This work was supported by a Natural Environment Research Council studentship to R.L.Tyne (Grant ref. NE/L002612/1) and the U.S. Geological Survey (Grant ref. 15-080-250), as part of the California State Water Resource Control Board's Oil and Gas Regional Groundwater Monitoring Program (RMP).

Description: Geological archives record multiple reversals of Earth's magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the Laschamps Excursion 41 to 42 thousand years ago (ka). We use ancient New Zealand kauri trees (Agathis australis) to develop a detailed record of atmospheric radiocarbon levels across the Laschamps Excursion. We precisely characterize the geomagnetic reversal and perform global chemistry-climate modeling and detailed radiocarbon dating of paleoenvironmental records to investigate impacts. We find that geomagnetic field minima ~42 ka, in combination with Grand Solar Minima, caused substantial changes in atmospheric ozone concentration and circulation, driving synchronous global climate shifts that caused major environmental changes, extinction events, and transformations in the archaeological record.

Description: After 25 years of gradual increase, volcanic unrest at La Soufrière of Guadeloupe reached its highest seismic en- ergy level on 27 April 2018, with the largest felt volcano-tectonic (VT) earthquake (ML 4.1 or MW 3.7) recorded since the 1976–1977 phreatic eruptive crisis. This event marked the onset ofa seismic swarm(180 events, 2 felt) occurring after three previous swarms on 3–6 January (70 events), 1 st February (30 events, 1 felt) and 16–17 April (140 events, 1 felt). Many events were hybrid VTs with long-period codas, located 2–4 km below the vol- cano summit and clustered within 2 km along a regional NW-SE fault cross-cutting La Soufrière. Elastic energy release increased with eachswarmwhereas inter-event time shortened. At the same time, summit fractures con- tinued to open and thermal anomalies to extend. Summit fumarolic activity increased significantly until 20 April, with a maximum temperature of111.4 °C and gas exit velocity of80 m/s, before declining to ~95 °C and ~33 m/s on 25 April. Gas compositions revealed increasing C/S and CO2/CH4 ratios and indicate hydrothermal P-T condi- tions that reached the critical point ofpure water. Repeated MultiGAS analysis of fumarolic plumes showed in- creased CO2/H2S ratios and SO2 contents associated with the reactivation of degassing fractures (T = 93 °C, H2S/SO2 ≈ 1). While no direct evidence ofupward magma migration was detected, we attribute the above phe- nomena to an increased supply ofdeepmagmatic fluids that heated and pressurized the La Soufrière hydrother- mal system, triggering seismogenic hydro-fracturing, and probable changes in deep hydraulic properties (permeability) and drainage pathways, which ultimately allowed the fumarolic fluxes to lower. Although this magmatic fluid injectionwasmodulated by the hydrothermal system, the unprecedented seismic energy release and the critical point conditions ofhydrothermal fluids suggest that the 2018 sequence ofevents can be regarded as a failed phreatic eruption. Should a similar sequence repeat, we warn that phreatic explosive activity could re- sult fromdisruption ofthe shallowhydrothermal system that is currently responsible for 3–9mm/y ofnearly ra- dial horizontal displacements within 1 km from the dome. Another potential hazard is partial collapse of the dome's SW flank, already affected by basal spreading above a detachment surface inherited from past collapses. Finally, the increased magmatic fluid supply evidenced by geochemical indicators in 2018 is compatible with magma replenishment of the 6–7 kmdeep crustal reservoir feeding La Soufrière and, therefore, with a potential evolution of the volcano's activity towards magmatic conditions.

Description: Published

Description: 106769

Description: 4V. Processi pre-eruttivi

Description: JCR Journal

Description: Young and tectonically active chains like the Central Apennines (Italy) are featured by high structural complexity as a result of the overprint of subsequent deformational stages, making interpretation of seismotectonics challenging. The Central Apennines are characterized by the stacking of tectono-sedimentary units organized in thrust sheets. However, extensional tectonics is currently affecting the axial sector of the thrust belt, mostly expressing in extensional earthquakes. Using a large subsurface dataset acquired for hydrocarbon exploration in the region struck by the 2016–2017 Central Italy seismic sequence, we built a comprehensive 3D geological model and compared it with the seismicity. The model primarily shows a series of thrusts developed during the Miocene-Pliocene Apennines orogenesis and inherited normal faults developed during the Mesozoic extensional phase and the Miocene foreland flexural process. These normal faults were segmented and transported within the thrust sheets, and sometimes they still show a clear surface expression. The succession of tectonic stages resulted in a widespread reactivation of inherited structures, sometimes inverting their kinematics with different styles and rates, and disarticulating pre-existing configurations. Such evolution has a strong impact on the seismicity observed in the area, as demonstrated by some examples that show how the seismicity is aligned on segments of inherited faults, both compressional and extensional. Their reactivation can be explained by their favorable orientation within the current extensional stress field. Results feed the debate about the seismogenic potential of faults identified both at depth and surface, which can impact the seismic hazard of the Apennines.

Description: Published

Description: 228861

Description: 1T. Struttura della Terra

Description: 2T. Deformazione crostale attiva

Description: 4T. Sismicità dell'Italia

Description: JCR Journal

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Melle, W., Klevjer, T., Drinkwater, K. F., Strand, E., Naustvoll, L. J., Wiebe, P. H., Aksnes, D. L., Knutsen, T., Sundby, S., Slotte, A., Dupont, N., Salvanes, A. G. V., Korneliussen, R., & Huse, G. Structure and functioning of four North Atlantic ecosystems - a comparative study. Deep-Sea Research Part II: Topical Studies in Oceanography, 180, (2020): 104838, doi:10.1016/j.dsr2.2020.104838.

Description: The epi- and mesopelagic ecosystems of four sub-polar ocean basins, the Labrador, Irminger, Iceland and Norwegian seas, were surveyed during two legs from Bergen, Norway, to Nuuk, Greenland, and back to Bergen. The survey was conducted from 1 May to 14 June, and major results were published in five papers (Drinkwater et al., Naustvoll et al., Strand et al., Melle et al., this issue, and Klevjer et al., this issue a, this issue b). In the present paper, the structures of the ecosystem are reviewed, and aspects of the functioning of the ecosystems examined, focusing on a comparison of trophic relationships in the four basins. In many ways, the ecosystems are similar, which is not surprising since they are located at similar latitudes and share many hydrographic characteristics, like input of both warm and saline Atlantic water, as well as cold and less saline Arctic water. Literature review suggests that total annual primary production is intermediate in the eastern basins and peaks in the Labrador Sea, while the Irminger Sea is the most oligotrophic sea. This was not reflected in the measurements of different trophic levels taken during the cruise. The potential new production was estimated to be higher in the Irminger Sea than in the eastern basins, and while the biomass of mesozooplankton was similar across basins, the biomass of mesopelagic micronekton was about one order of magnitude higher in the western basins, and peaked in the Irminger Sea, where literature suggests annual primary production is at its lowest. The eastern basins hold huge stocks of pelagic planktivore fish stocks like herring, mackerel and blue whiting, none of which are abundant in the western seas. As both epipelagic nekton and mesopelagic micronekton primarily feed on the mesozooplankton, there is likely competitive interactions between the epipelagic and mesopelagic, but we're currently unable to explain the estimated ~1 order of magnitude difference in micronekton standing stock. The results obtained during the survey highlight that even if some aspects of pelagic ecosystems are well understood, we currently do not understand overall pelagic energy flow in the North Atlantic.

Description: We greatly appreciate the Captain and crew of the R.V. G.O. Sars for their dedication and help during the BASIN survey. We also thank the technical support from the Institute of Marine Research that helped during the cruise and those that contributed to the processing and analysis of the data on land. The sampling, data analysis and reporting have been supported by IMR and University of Bergen through funding of ship time, laboratory costs and salaries of researchers through internally funded projects. We would also like to acknowledge the funding from Euro-BASIN, EU FP7, Grant agreement No 264933, HARMES, Research Council of Norway project number 280546 and MEESO, EU H2020 research and innovation programme, Grant Agreement No 817669. KD undertook this study as part of the Ecosystem Studies of Subarctic and Arctic Seas (ESSAS) programme.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in DiBenedetto, M., Qin, Z., & Suckale, J. Crystal aggregates record the pre-eruptive flow field in the volcanic conduit at Kilauea, Hawaii. Science Advances, 6(49), (2020): eabd4850, doi:10.1126/sciadv.abd4850.

Description: Developing reliable, quantitative conduit models that capture the physical processes governing eruptions is hindered by our inability to observe conduit flow directly. The closest we get to direct evidence is testimony imprinted on individual crystals or bubbles in the conduit and preserved by quenching during the eruption. For example, small crystal aggregates in products of the 1959 eruption of Kīlauea Iki, Hawaii contain overgrown olivines separated by large, hydrodynamically unfavorable angles. The common occurrence of these aggregates calls for a flow mechanism that creates this crystal misorientation. Here, we show that the observed aggregates are the result of exposure to a steady wave field in the conduit through a customized, process-based model at the scale of individual crystals. We use this model to infer quantitative attributes of the flow at the time of aggregate formation; notably, the formation of misoriented aggregates is only reproduced in bidirectional, not unidirectional, conduit flow.

Description: M.D. acknowledges support the Stanford Gerald J. Lieberman Fellowship and the Postdoctoral Scholarship from Woods Hole Oceanographic Institution.

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Mohtar, A. T., Hughen, K. A., Goodkin, N. F., Streanga, I., Ramos, R. D., Samanta, D., Cervino, J., & Switzer, A. D. Coral-based proxy calibrations constrain ENSO-driven sea surface temperature and salinity gradients in the Western Pacific Warm Pool. Palaeogeography Palaeoclimatology Palaeoecology, 561, (2021): 110037, doi:10.1016/j.palaeo.2020.110037.

Description: Constraining past variability in ocean conditions in the Western Pacific Warm Pool (WPWP) and examining how it has been influenced by the El-Niño Southern Oscillation (ENSO) is critical to predicting how these systems may change in the future. To characterize the spatiotemporal variability of the WPWP and ENSO during the past three decades, we analyzed climate proxies using coral cores sampled from Porites spp. from Kosrae Island (KOS) and Woleai Atoll (WOL) in the Federated States of Micronesia. Coral skeleton samples drilled along the major growth axis were analyzed for oxygen isotopes (δ18Oc) and trace element ratios (Sr/Ca), used to reconstruct sea surface salinity and temperature (SSS and SST). Pseudocoral δ18O time series (δ18Opseudo) were calculated from gridded instrumental observations and compared to δ18Oc, followed by fine-tuning using coral Sr/Ca and gridded SST, to produce age models for each coral. The thermal component of δ18Oc was removed using Sr/Ca for SST, to derive δ18O of seawater (δ18Osw), a proxy for SSS. The Sr/Ca, and δ18Osw records were compared to instrumental SST and SSS to test their fidelity as regional climate recorders. We found both sites display significant Sr/Ca-SST calibrations at monthly and interannual (dry season, wet season, mean annual) timescales. At each site, δ18Osw also exhibited significant calibrations to SSS across the same timescales. The difference between normalized dry season SST (Sr/Ca) anomalies from KOS and WOL generates a zonal SST gradient (KOSWOLSST), capturing the east-west WPWP migration observed during ENSO events. Similarly, the average of normalized dry season δ18Osw anomalies from both sites produces an SSS index (KOSWOLSSS) reflecting the regional hydrological changes. Both proxy indices, KOSWOLSST and KOSWOLSSS, are significantly correlated to regional ENSO indices. These calibration results highlight the potential for extending the climate record, revealing spatial hydrological gradients within the WPWP and ENSO variability back to the end of the Little Ice Age.

Description: We also thank the crew of the M/V Alucia for assistance during the 2012 coral drilling expedition to FSM, funded by the Dalio Family Foundation through a WHOI Access to The Sea grant to KAH (#25110104). Geochemical analysis was funded by Singapore Ministry of Education Academic Research Fund Tier-2 (# MOE2016-T2-1016) to NFG and KAH, and by the WHOI Summer Student Fellowship Program (00450400) and Coastal Preservation Network 501c to IMS.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chen, S., Tao, C., & German, C. R. . Hydrothermal plume detection dataset from Chinese cruises to the equatorial East Pacific Rise. Data in Brief, 33, (2020): 106540, doi:10.1016/j.dib.2020.106540.

Description: In this data article, a dataset from hydrothermal plume investigations on East Pacific Rise collected during Chinese cruises from 2008 to 2011 is reported. The dataset is related to the research article entitled “Abundance of low-temperature axial venting at the equatorial East Pacific Rise” published in the journal Deep-Sea Research I by Chen et al. (2020). In the dataset, continuous strings of time-series sensor data were obtained by Miniature Autonomous Plume Recorders (MAPR) and an Oxidation-Reduction Potential (ORP) sensor, while the underwater position data was derived using Ultra Short Base Line (USBL) navigation. In this contribution, general characteristics of the data are summarized and showed here. All the data are stored in separate Microsoft Excel spreadsheets that are available for researchers and a link is provided to the full data at http://dx.doi.org/10.17632/jckyj5vyjx.1. The data will be of comparative value to those investigating hydrothermal activities along mid-ocean ridges, worldwide.

Description: We acknowledge the science parties and crew of Dayang YiHao expedition DY17 in 2005, DY20 in 2008, DY21 in 2009 and DY22 in 2011 for data collection. Fieldwork for this study was funded by National Key Research and Development Program of China (2018YFC0309901), China Ocean Mineral Resources R & D Association (COMRA) Project (DY135-S1-1-01, 02, 09) and Natural Science Foundation of Zhejiang Province (LQ19D060008). SC recognizes financial support from China Scholarship Council which supported her visit to WHOI where the data analysis for this paper occurred (201808330070); CG recognizes financial support from US National Science Foundation grant OCE-1755571 and from WHOI. We are grateful to the contributions made by Guanghai Wu, Yongshun John Chen, Jianyu Ni, Jian Lin, Xin Su, Jianping Zhou and Yuan Wang - both for overseeing the cruises during which the ORP and MAPR sensor data reported here were collected but also for their thoughtful suggestions during those cruises.