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  • Articles  (226)
  • Open Access-Papers  (226)
  • Springer  (204)
  • American Physical Society
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  • 2010-2014  (226)
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  • Articles  (226)
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  • 1
    Publication Date: 2014-09-30
    Description: Marine viruses are ubiquitous, extremely diverse, and outnumber any form of life in the sea. Despite their ecological importance, viruses in marine environments have been largely ignored by the academic community, and only those that have caused substantial economic losses have received more attention. Fortunately, our current understanding on marine viruses has advanced considerably during the last decades. These advances have opened new and exciting research opportunities as several unique structural and genetic characteristics of marine viruses have shown to possess an immense potential for various biotechnological applications. Here, a condensed overview of the possibilities of using the enormous potential offered by marine viruses to develop innovative products in industries as pharmaceuticals, environmental remediation, cosmetics, material sciences, and several others, is presented. The importance of marine viruses to biotechnology should not be underestimated.
    Repository Name: EPIC Alfred Wegener Institut
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  • 2
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    In:  EPIC3Global Environmental Change, (Handbook of Global Environmental Pollution ;1), Dordrecht ; London, Springer, 973 p., pp. 103-110, ISBN: 978-94-007-5783-7
    Publication Date: 2014-10-08
    Repository Name: EPIC Alfred Wegener Institut
    Type: Inbook , peerRev
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  • 3
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    In:  EPIC3Global Land Ice Measurements from Space, Berlin Heidelberg, Springer, pp. 717-741, ISBN: 978-3-540-79817-0
    Publication Date: 2016-11-15
    Description: The Antarctic Peninsula has exhibited some of the most spectacular changes observed in glacial systems in recent decades. The events include disintegration of ice shelves, acceleration and thinning of glaciers, variations in the limits between glacier facies, and retreat of glacier fronts. However, due to the lack of both consistent systematic observations of the glacial systems and information on their boundary conditions, it is difficult to accurately predict the contribution of Antarctic Peninsula glaciers to sea level rise and further responses of these ice masses to climatic and oceanographic changes. In this context, the activities of the GLIMS Regional Center for the Antarctic Peninsula and its network of international collaborators are based on the use of various types of Earth observation imagery, mainly optical and radar data. Although a complete glacier inventory is still lacking, we present the results of changes in glacier frontal positions and boundaries of glacier facies as well as links to dynamical adjustments for various locations in the Antarctic Peninsula’s ice masses. Evaluation of Advanced Spaceborne Thermal Emission and reflection Radiometer (ASTER) digital elevation models generated for the Antarctic Peninsula is also discussed.
    Repository Name: EPIC Alfred Wegener Institut
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  • 4
    Publication Date: 2016-10-22
    Repository Name: EPIC Alfred Wegener Institut
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  • 5
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    In:  EPIC3Marine Biology, Springer, 161(12), pp. 2819-2829, ISSN: 0025-3162
    Publication Date: 2015-01-16
    Description: Among bivalves, scallops are exceptional due to their capacity to escape from predators by swimming which is provided by rapid and strong claps that are produced by the phasic muscle interspersed with tonic muscle contractions. Based on the concept of oxygen and capacity-limited thermal tolerance, the following hypothesis was tested: ocean warming and acidification (OWA) would induce disturbances in aerobic metabolic scope and extracellular acid-case status and impair swimming performance in temperate scallops. Following longterm incubation under near-future OWA scenarios [20 vs. 10 °C (control) and 0.112 kPa CO2 (hypercapnia) vs. 0.040 kPa CO2 (normocapnic control)], the clapping performance and metabolic rates (MR) were measured in resting (RMR) and fatigued (maximum MR) king scallops, Pecten maximus, from Roscoff, France. Exposure to OA, either alone or combined with warming, left MR and swimming parameters such as the total number of claps and clapping forces virtually unchanged. Only the duration of the escape response was affected by OA which caused earlier exhaustion in hyper- than in normocapnic scallops at 10 °C. While maximum MR was unaffected, warm exposure increased RMR in both normocapnic and hypercapnic P. maximus resulting in similar Q10 values of ~2.2. The increased costs of maintenance and the observation of strongly reduced haemolymph PO2 levels indicate that at 20 °C scallops have reached the upper thermal pejus range with unbalanced capacities for aerobic energy metabolism. As a consequence, warming to 20 °C decreased mean phasic force during escape performance until fatigue. The observed prolonged recovery time in warm incubated scallops might be a consequence of elevated metabolic costs at reduced oxygen availability in the warmth.
    Repository Name: EPIC Alfred Wegener Institut
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  • 6
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    Springer
    In:  EPIC3Encyclopedia of Earthquake Engineering, Encyclopedia of Earthquake Engineering, Berlin, Heidelberg, Springer, pp. 1-16, ISBN: 978-3-642-36197-5
    Publication Date: 2014-12-16
    Repository Name: EPIC Alfred Wegener Institut
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  • 7
    Publication Date: 2017-04-04
    Description: Remote sensing thermal data of active lava flows allow for the evaluation of instantaneous effusion rates. This is made possible by simple formulae relating the lava effusion rate to the power energy radiated per unit time from the surface to the flow. Such formulae are based on a specific flow model and, consequently, their validity is subject to the model assumptions. The most questionable assumption is probably the constancy of the surface temperature. Herein, we use high spatial resolution infrared data to demonstrate the existence of an underlying relationship between the surface temperature and the lava flow thickness, using the 2001 Mt. Etna flow as a case study. According to this relationship, observed changes in surface temperature does not represent a weakness of the model but is the expected consequence of actual variations in the topographic down flow profile.
    Description: Published
    Description: 391-408
    Description: 3V. Dinamiche e scenari eruttivi
    Description: restricted
    Keywords: Remote sensing, effusion rate, heat flux, Etna, MIVIS ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 8
    Publication Date: 2017-04-04
    Description: Here, we report the first continuous data of geochemical parameters acquired directly from the active summit crater of Vulcano. This approach provides a means to better investigate deep geochemical processes associated with the degassing system of Vulcano Island. In particular, we report on soil CO2 fluxes from the upper part of Vulcano, a closed-conduit volcano, from September 2007 to October 2010. Large variations in the soil CO2 and plume SO2 fluxes (order of magnitude), coinciding with other discontinuous geochemical parameters (CO2 concentrations in fumarole gas) and physical parameters (increase of shallow seismic activity and fumarole temperatures) have been recorded. The results from this work suggest new prospects for strengthening geochemical monitoring of volcanic activity and for improving the constraints in the construction of a “geochemical model”, this being a necessary condition to better understand the functioning of volcanic systems.
    Description: Published
    Description: 1859-1863
    Description: 2V. Dinamiche di unrest e scenari pre-eruttivi
    Description: 4V. Vulcani e ambiente
    Description: 5V. Sorveglianza vulcanica ed emergenze
    Description: 1R. Reti di monitoraggio e Osservazioni
    Description: JCR Journal
    Description: restricted
    Keywords: Vulcano Island ; Geochemical monitoring ; CO2 flux ; CO2 fumaroles ; SO2 flux ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 9
    Publication Date: 2017-04-04
    Description: Laboratory experiments have shown that the finer the grain size of granular flows of angular rock fragments (all the other features the same), the more mobile their centre of mass. This is due to the fact that the finer the grain size, the larger the number of particles in the flow so that their agitation due to the interaction with the subsurface asperities has a smaller penetration within the flow. The smaller the agitation of the particles per unit of flow mass, the smaller the energy dissipated per unit of travel distance. Also, the larger the flow volume, the smaller the mobility of its centre of mass. This is due to the fact that a deposit accretes backward during its deposition on a slope change. However, the frontal end of a larger-volume deposit is more distal than that of a smaller-volume deposit because the larger the volume, the larger its longitudinal spreading.
    Description: Published
    Description: 1621-1624
    Description: 3V. Dinamiche e scenari eruttivi
    Description: restricted
    Keywords: Pyroclastic Flows ; Mobility ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 10
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    In:  EPIC3Science China Earth Sciences, Springer, 57(4), pp. 703-709, ISSN: 1674-7313
    Publication Date: 2015-01-14
    Description: The European Centre for Medium-Range Weather Forecasts Reanalysis ERA40, National Centers for Environmental Prediction (NCEP) 20th-century reanalysis, and three station observations along an Antarctic traverse from Zhongshan to Dome-A stations are used to assess 2-m temperature simulation skill of a regional climate model. This model (HIRHAM) is from the Alfred Wegener Institute for Polar and Marine Research in Germany. Results show: (1) The simulated multiyear averaged 2-m temperature field pattern is close to that of ERA40 and NCEP; (2) the cold bias relative to ERA40 over all of Antarctic regions is 1.8°C, and that to NCEP reaches 5.1°C; (3) bias of HIRHAM relative to ERA40 has seasonal variation, with a cold bias mainly in the summer, as much as 3.4°C. There is a small inland warm bias in autumn of 0.3°C. Further analysis reveals that the reason for the cold bias of 2-m temperature is that physical conditions of the near-surface boundary layer simulated by HIRHAM are different from observations: (1) During the summer, observations show that near-surface atmospheric stability conditions have both inversions and non-inversions, which is due to the existence of both positive and negative sensible heat fluxes, but HIRHAM almost always simulates a situation of inversion and negative sensible heat flux; (2) during autumn and winter, observed near-surface stability is almost always that of inversions, consistent with HIRHAM simulations. This partially explains the small bias during autumn and winter.
    Repository Name: EPIC Alfred Wegener Institut
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  • 11
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    In:  EPIC3Encyclopedia of Complexity and Systems Science, Encyclopedia of Complexity and Systems Science, Springer, pp. 1-30
    Publication Date: 2015-03-10
    Repository Name: EPIC Alfred Wegener Institut
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  • 12
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    In:  EPIC3Helgoland Marine Research, Springer, 68(1), pp. 1-16, ISSN: 1438-387X
    Publication Date: 2016-07-19
    Description: Exposed sandy coasts are predominantly physically controlled environments where benthic communities are structured by the independent response of species to the physical environment, with minimal biological interactions (swash exclusion hypothesis). This prevalence of physical control may be regarded as a typical property of exposed coastal areas. In an offshore direction, the importance of wave effects on the benthos will diminish until a depth is reached where they are no longer significant [wave exclusion hypothesis (WEH)]. This loss of a coastal property may be used to define an offshore depth limit of the coastal zone. We used a large set of benthos data from the SE North Sea to test whether an offshore limit of the coast can be clearly recognised despite strong small-scale variability and how this limit would vary seasonally and from year to year. In accordance with WEH, both species density and total abundance of macrobenthos were low in the surf zone, strongly increased with depth, and averaged over all sampling dates became relatively constant below 30 m depth. Seasonally, these gradients were weaker during summer recruitment than during autumn. Species richness, by contrast, showed no significant difference with depth. In single years, the depth of the turning point from increasing abundances to constant abundances varied between 20 and 31 m (equivalent to 40–80 km off the coastline) depending on wave height. We conclude that this zone can be derived from benthic community gradients.
    Repository Name: EPIC Alfred Wegener Institut
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  • 13
    Publication Date: 2019-07-17
    Description: Cephalopods have been utilised in neurosci- ence research for more than 100 years particularly because of their phenotypic plasticity, complex and centralised nervous system, tractability for studies of learning and cellular mechanisms of memory (e.g. long-term potentia- tion) and anatomical features facilitating physiological studies (e.g. squid giant axon and synapse). On 1 January 2013, research using any of the about 700 extant species of ‘‘live cephalopods’’ became regulated within the European Union by Directive 2010/63/EU on the ‘‘Protection of Animals used for Scientific Purposes’’, giving cephalopods the same EU legal protection as previously afforded only to vertebrates. The Directive has a number of implications, particularly for neuroscience research. These include: (1) projects will need justification, authorisation from local competent authorities, and be subject to review including a harm-benefit assessment and adherence to the 3Rs princi- ples (Replacement, Refinement and Reduction). (2) To support project evaluation and compliance with the new EU law, guidelines specific to cephalopods will need to be developed, covering capture, transport, handling, housing, care, maintenance, health monitoring, humane anaesthesia, analgesia and euthanasia. (3) Objective criteria need to be developed to identify signs of pain, suffering, distress and lasting harm particularly in the context of their induction by an experimental procedure. Despite diversity of views existing on some of these topics, this paper reviews the above topics and describes the approaches being taken by the cephalopod research community (represented by the authorship) to produce ‘‘guidelines’’ and the potential contribution of neuroscience research to cephalopod welfare.
    Repository Name: EPIC Alfred Wegener Institut
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  • 14
    Publication Date: 2014-05-06
    Description: Developmental and reproductive parameters and their relationships were studied in the marine isopod Idotea linearis. We hypothesized that (1) the temporal patterns of molting and growth undergo complex and sex-specific changes with age as well as with the onset of sexual maturation, and that (2) sexual maturation (and dependent parameters) is controlled by the photoperiod. Both males and females were singly cultured in the laboratory at two alternative photoperiods (constant long and short days, respectively) from hatching until death. Males molted and grew throughout their life, showing a steady increase in stage duration and body size with each molt. Females, in contrast, showed much more complex modifications in molt chronology due to reproductive demands. There was some variability in the stage number, when females reached maturity. Reaching maturity early in the succession of molts was associated with smaller body size at maturity, smaller size of broods, but higher average number of broods per lifetime. Post-puberty molts in females occurred without further growth, and successive broods did not differ in size. The photoperiod strongly affected sexual maturation (and thus in turn molting and growth patterns) in females, while males remained completely unaffected by the photo regime.
    Repository Name: EPIC Alfred Wegener Institut
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  • 15
    Publication Date: 2019-07-17
    Description: This study examines present-day changes of the Antarctic ice sheet (AIS) by means of different data sets. We make use of monthly gravity field solutions acquired by the Gravity Recovery and Climate Experiment (GRACE) to study mass changes of the AIS for a 10-year period. In addition to "standard" solutions of release 05, solutions based on radial base functions were used. Both solutions reveal an increased mass loss in recent years. For a 6-year period surface-height changes were inferred from laser altimetry data provided by the Ice, Cloud, and land Elevation Satellite (ICESat). The basin-scale volume trends were converted into mass changes and were compared with the GRACE estimates for the same period. Focussing on the Thwaites Glacier, Landsat optical imagery was utilised to determine ice-flow velocities for a period of more than two decades. This data set was extended by means of high-resolution synthetic aperture radar (SAR) data from the TerraSAR-X mission, revealing an accelerated ice flow of all parts of the glacier. ICESat data over the Thwaites Glacier were complemented by digital elevation models inferred from TanDEM-X data. This extended data set exhibits an increased surface lowering in recent times. Passive microwave remote sensing data prove the long-term stability of the accumulation rates in a low accumulation zone in East Antarctica over several decades. Finally, we discuss the main error sources of present-day mass-balance estimates: the glacial isostatic adjustment effect for GRACE as well as the biases between laser operational periods and the volume-mass conversion for ICESat.
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  • 16
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    In:  EPIC3Regional Environmental Change, Springer, ISSN: 1436-3798
    Publication Date: 2016-10-07
    Description: This article aims to address the challenges of sustainable earth system governance from a multi-scale level perspective. The local to regional system level reviews findings from a social-ecological system (SES) approach of a mangrove ecosystem in North Brazil. Seven challenges (Glaser et al. 2010) that could provide relevant knowledge to society were identified. Their respective justification and recommendations are presented here. Further, these “challenges from the field” are linked and discussed with those challenges on earth system level elaborated by the International Council for Science in 2010. There it was stressed that sustainability problems are increasingly caused by drivers from multiple spatial and institutional levels in a single global human-nature system. The comparison between the global and local to regional challenges shows that most of these are reappearing disregarding the level of analysis, indicating that there is a universal core of global change problems. However, there are gaps are visible which hamper the effective connections across the different spatial levels. These gaps pertain to i.e. the subjects of knowledge generation and stakeholder inclusion. The final section elaborates on these recognized gaps and their science-policy dimensions. The article closes with the identification of a number of factors which currently impede global sustainability efforts: shortcomings in inter- and transdisciplinary research practice, lack of consistent structures for earth system governance and shortcomings in dealing with up-scaling challenges whilst remaining locally relevant. A blueprint for a globally focused but regionally informed social-ecological analysis framework remains to be worked out.
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  • 17
    Publication Date: 2019-07-16
    Description: Milleporidae are of high ecological and economic importance, as, together with the scleractinian corals, they belong to the main reef builders of tropical coral reefs. Coral reefs face severe threats mainly due to anthropogenic disturbance. Understanding their population structure and dynamics is crucial for any conservation effort. Here we report the first microsatellite loci for the Milleporidae. Eleven polymorphic markers were developed for the hydrozoan corals Millepora dichotoma from the Great Barrier Reef (Australia) and tested for amplification in M. dichotoma from the Red Sea (Egypt), as well as for Millepora platyphylla from the Pacific Ocean (Moorea, French Polynesia). All loci were variable with 4–15 alleles per locus. Nine loci were transferable between geographic regions and species. These are the first microsatellites for hydrozoan corals. They will provide valuable tools for characterizing the population structure and genetic diversity of the group thereby benefitting coral reef conservation.
    Repository Name: EPIC Alfred Wegener Institut
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  • 18
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    American Physical Society
    In:  EPIC3Physical Review E, American Physical Society, 90, pp. 022711-1, ISSN: 1539-3755
    Publication Date: 2014-11-04
    Description: The fascinating ability of algae, insects, and fishes to survive at temperatures below normal freezing is realized by antifreeze proteins (AFPs). These are surface-active molecules and interact with the diffusive water-ice interface thus preventing complete solidification. We propose a dynamical mechanism on how these proteins inhibit the freezing of water. We apply a Ginzburg-Landau-type approach to describe the phase separation in the two-component system (ice, AFP). The free-energy density involves two fields: one for the ice phase with a low AFP concentration and one for liquid water with a high AFP concentration. The time evolution of the ice reveals microstructures resulting from phase separation in the presence of AFPs. We observed a faster clustering of pre-ice structure connected to a locking of grain size by the action of AFP, which is an essentially dynamical process. The adsorption of additional water molecules is inhibited and the further growth of ice grains stopped. The interfacial energy between ice and water is lowered allowing the AFPs to form smaller critical ice nuclei. Similar to a hysteresis in magnetic materials we observe a thermodynamic hysteresis leading to a nonlinear density dependence of the freezing point depression in agreement with the experiments.
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  • 19
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    In:  EPIC3Neurochemical Research, Springer, 39(2), pp. 372-383, ISSN: 0364-3190
    Publication Date: 2019-07-17
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  • 20
    Publication Date: 2014-05-12
    Description: We investigated microbial life preserved in a hydrothermally inactive silica–barite chimney in comparison with an active barite chimney and sediment from the Loki’s Castle low-temperature venting area at the Arctic Mid-Ocean Ridge (AMOR) using lipid biomarkers. Carbon and sulfur isotopes were used to constrain possible metabolic pathways. Multiple sulfur (δ34S, ∆33S) isotopes on barite over a cross section of the extinct chimney range between 21.1 and 22.5 ‰ in δ34S, and between 0.020 and 0.034 ‰ in Δ33S, indicating direct precipitation from seawater. Biomarker distributions within two discrete zones of this silica–barite chimney indicate a considerable difference in abundance and diversity of microorganisms from the chimney exterior to the interior. Lipids in the active and inactive chimney barite and sediment were dominated by a range of 13C-depleted unsaturated and branched fatty acids with δ13C values between −39.7 and −26.7 ‰, indicating the presence of sulfur-oxidizing and sulfate-reducing bacteria. The majority of lipids (99.5 %) in the extinct chimney interior that experienced high temperatures were of archaeal origin. Unusual glycerol monoalkyl glycerol tetraethers (GMGT) with 0–4 rings were the dominant compounds suggesting the presence of mainly (hyper-) thermophilic archaea. Isoprenoid hydrocarbons with δ13C values as low as −46 ‰ also indicated the presence of methanogens and possibly methanotrophs.
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  • 21
    Publication Date: 2014-09-04
    Description: Understanding phylogenetic relationship and patterns of contemporary population genetic structure is a prerequisite for conservation and management of potential fishery resources. In this study we report the isolation and characterization of 11 polymorphic microsatellite loci for the squat lobster Munida gregaria from around the Falkland Islands/Islas Malvinas. The number of alleles ranged from 3 to 31, observed heterozygosity varied from 0.130 to 0.870. Cross-amplification was 100 % successfully in the species/morph M. subrugosa and 36.4 % in another congeneric species M. gracilis. This set of microsatellites is useful for studies focused on taxonomy, genetic diversity and genetic connectivity further may provide stock assessment information for monitoring this important fishery resource.
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  • 22
    Publication Date: 2018-08-10
    Description: Marine habitats worldwide are increasingly pressurized by climate change, especially along the Antarctic Peninsula. Well-studied areas in front of rapidly retreating tidewater glaciers like Potter Cove are representative for similar coastal environments and, therefore, shed light on habitat formation and development on not only a local but also regional scale. The objective of this study was to provide insights into habitat distribution in Potter Cove, King George Island, Antarctica, and to evaluate the associated environmental processes. Furthermore, an assessment concerning the future development of the habitats is provided. To describe the seafloor habitats in Potter Cove, an acoustic seabed discrimination system (RoxAnn) was used in combination with underwater video images and sediment samples. Due to the absence of wave and current measurements in the study area, bed shear stress estimates served to delineate zones prone to sediment erosion. On the basis of the investigations, two habitat classes were identified in Potter Cove, namely soft-sediment and stone habitats that, besides influences from sediment supply and coastal morphology, are controlled by sediment erosion. A future expansion of the stone habitat is predicted if recent environmental change trends continue. Possible implications for the Potter Cove environment, and other coastal ecosystems under similar pressure, include changes in biomass and species composition.
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  • 23
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    In:  EPIC3Plant Cold Acclimation: Methods and Protocols, (Methods in Molecular Biology ; 1166), New York, Springer, 282 p., pp. 241-253, ISBN: 978-1-4939-0843-1
    Publication Date: 2014-09-24
    Description: ICE BINDING PROTEINS FROM SEA ICE ALGAE Sea ice is mainly a two-phase system, and its porous structure is largely determinant for biological activity within ice. During ice formation, solutes in the seawater are excluded from the ice matrix and segregate into brine droplets or brine channels, generally defined as brine inclusions inside sea ice. Outflow of high salinity brine and inflow of seawater of lower salinity, as well as further cooling, cause brine inclusions to narrow and eventually separate into individual pockets divided by ice bridges. Despite the harsh conditions that govern within sea ice, where temperatures range from about -1.8°C on the bottom to -20°C or less on the top, and brine salinities can be as high as 200 on the Practical Salinity Scale, brine inclusions offer a habitat for a variety of microalgae. These algae play a crucial role for the ecology of the Polar Oceans, since they represent a concentrated food source in the low-productivity ice-covered sea, and in the months of melting they initiate blooms by seeding the water column. Algae have been found distributed within brine inclusions throughout the entire thickness of the ice column. The strategies adopted by ice microorganisms to cope with conditions in sea ice remain to be unraveled. Recent studies showed that several organisms that populate sea ice, spreading from bacteria to diatoms and a crustacean species, have ice binding proteins (IBPs). These proteins are common in polar species, but lack in temperate organisms, suggesting that IBPs play a key role in adaptation to subzero conditions. The nomenclature of these proteins varies, depending on authors, from ice binding to antifreeze or ice structuring. In the generally accepted adsorption–inhibition model describing the mechanism of action of IBPs, proteins bind to the ice lattice and locally inhibit ice growth by the Gibbs-Thomson effect. Recent publications showed that some IBPs organize water molecules into an ice-like structure that matches defined planes of the ice crystal and is then gradually frozen to the ice lattice. One of the most prominent and best described effects of IBPs is thermal hysteresis, which describes the lowering of the freezing point of a solution below the melting point. Another effect which defines IBPs is inhibition of recrystallization, which is the grain boundary migration resulting in a growth of larger crystals at the expenses of small grains. The biological role of IBPs from sea ice microalgae remains an open question. The importance of some IBP families, as observed in fishes or insects, lies in lowering the freezing point below environmental temperature, in order to avoid ice formation in cells or organs. Other IBPs have the function to inhibit recrystallization, as it has been suggested for plant IBPs. In the context of sea ice, it seems unlikely that the biological role of IBPs may be thermal hysteresis (measured in the order of 1°C) or recrystallization inhibition. Most of the IBPs from sea ice algae are active extracellularly. It has been suggested that they are trapped and accumulate within a layer of extracellular polysaccharide substances (EPS) secreted by several sea ice organisms. Microalgal IBPs produced recombinantly or collected from spent growth medium affect the structure of ice surface, causing pitting and characteristic microstructural features. This suggests that the proteins shape their frozen environment in order to increase their habitable space within sea ice. However, the characterization of IBPs is of relevance not only to understand their functional role in sea ice, but also in the frame of possible applications of IBPs in the medical field, in the food industry and in other fields related to a control of ice crystals. In the following we present some standard techniques to determine the protein activity in terms of thermal hysteresis (TH) and recrystallization inhibition (RI), which define the proteins as ice binding. Also, we present further methods (ice pitting assay, determination of the nucleating temperature) to characterize the activity of IBPs.
    Repository Name: EPIC Alfred Wegener Institut
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  • 24
    Publication Date: 2019-10-23
    Description: Characteristics of cyclones (frequency, intensity and size) and their changes in the Arctic region in a warmer climate have been analyzed with the use of the HIRHAM regional climate model simulations with SRES-A1B anthropogenic scenario for the twenty first century. The focus was on cyclones for the warm (April–September) and cold (October–March) seasons. The present-day cyclonic characteristics from HIRHAM simulations are in general agreement with those from ERA–40 reanalysis data. Differences noted for the frequency of cyclones are related with different spatial resolution in the model simulations and reanalysis data. Potential future changes in cyclone characteristics at the end of the twenty first century have been analyzed. According to the model simulations, the frequency of cyclones is increasing in warm seasons and decreasing in cold seasons for a warmer climate in the twenty first century, but these changes are statistically insignificant. Noticeable changes were detected for the intensity and size of cyclones for the both seasons. Significant increase was found for the frequency of weak cyclones during cold season. Further, a general increase in the frequency of small cyclones was calculated in cold seasons, while its frequency decreases in warm seasons.
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  • 25
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    In:  EPIC3Marine Biology, Springer, ISSN: 0025-3162
    Publication Date: 2019-07-17
    Description: Predation of eggs and nauplii by adult copepods is often used to explain unexpected death rates in population dynamics studies, but the phenomenon has been rarely investigated or quantified. Therefore, we studied the predatory feeding of adult females (Acartia clausi, Centropages hamatus, Centropages typicus, and Temora longicornis) on their own and other species’ eggs and young nauplii with different densities of single animal-prey, mixtures of animal-prey and in the presence of diatoms. All species preyed on eggs and nauplii of their own and all other species. Maximal egg predation varied between 7 and 64 eggs fem−1 day−1. Ingestion of Centropages spp. eggs was lowest, potentially due to the spiny egg surface. Maximal feeding rates on nauplii ranged from 5 to 45 nauplii fem−1 day−1. T. longicornis preferred eggs, when eggs and nauplii were offered together at the same densities, and the other predators selected for nauplii. At a diatom concentration of 60 μg C l−1 predation on eggs by C. typicus was higher than without algae, whereas A. clausi and T. longicornis did not change their uptake of eggs. Feeding on nauplii in the presence of diatoms was again enhanced in C. typicus, and unaffected in A. clausi and C. hamatus. T. longicornis reduced its feeding on nauplii in the presence of diatoms. Calculated predation rates, using field abundances of predators and prey, suggest that predation of copepods on their own young stages may account for ca. 30 % of total mortality of young stages in North Sea copepod populations.
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  • 26
    Publication Date: 2019-07-17
    Description: Young larval stages of many organisms represent bottlenecks in the life-history of many species. The high mortality commonly observed in, for example, decapod larvae has often been linked to poor nutrition, with most studies focussing on food quantity. Here, we focus instead on the effects of quality and have investigated its effects on the nutritional condition of lobster larvae. We established a tri-trophic food chain consisting of the cryptophyte Rhodomonas salina, the calanoid copepod Acartia tonsa and larvae of the European lobster Homarus gammarus. In a set of experiments, we manipulated the C:N:P stoichiometry of the primary producers, and accordingly those of the primary consumer. In a first experiment, R. salina was grown under N- and P-limitation and the nutrient content of the algae was manipulated by addition of the limiting nutrient to create a food quality gradient. In a second experiment, the effect on lobster larvae of long- and short-term exposure to food of varying quality during ontogenetic development was investigated. The condition of the lobster larvae was negatively affected even by subtle N- and P-nutrient limitations of the algae. Furthermore, younger lobster larvae were more vulnerable to nutrient limitation than older ones, suggesting an ontogenetic shift in the capacity of lobster larvae to cope with low quality food. The results presented here might have substantial consequences for the survival of lobster larvae in the field, as, in the light of future climate change and re-oligotrophication of the North Sea, lobster larvae might face marked changes in temperature and nutrient conditions, thus significantly altering their condition and growth.
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  • 27
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    In:  EPIC3Journal of Comparative Physiology B-Biochemical Systemic and Environmentalphysiol, Springer, ISSN: 0174-1578
    Publication Date: 2019-07-16
    Description: The digestive ability of four sympatric land crabs species (the gecarcinids, Gecarcoidea natalis and Discoplax celeste and the anomurans, Birgus latro and Coenobita perlatus) was examined by determining the activity of their digestive enzymes. The gecarcinids are detritivores that consume mainly leaf litter; the robber crab, B. latro, is an omnivore that preferentially consumes items high in lipid, carbohydrate and/or protein; C. perlatus is also an omnivore/detritivore. All species possess protease, lipase and amylase activity for hydrolysing ubiquitous protein, lipid and storage polysaccharides (glycogen and starch). Similarly all species possess enzymes such as N-acetyl-β-d-glucosaminidase, the cellulases, endo-β-1,4-glucanase and β-glucohydrolase and hemicellulases, lichenase and laminarinase for the respective hydrolysis of structural substrates chitin, cellulose and hemicelluloses, lichenan and laminarin. Except for the enzyme activities of C. perlatus, enzyme activity could not be correlated to dietary preference. Perhaps others factors such as olfactory and locomotor ability and metabolic status may determine the observed dietary preferences. The digestive fluid of C. perlatus possessed higher endo-β-1,4-glucanase, lichenase and laminarinase activities compared to that of the other species. Thus, C. perlatus may be efficient at digestion of cellulose and hemicellulose within plant material. Zymography indicated that the majority of protease, lipase, phosphatase, amylase, endo-β-1,4-glucanase, β-glucohydrolase and N-acetyl-β-d-glucosaminidase isozymes were common to all species, and hence were inherited from a common aquatic ancestor. Differences were observed for the phosphatase, lipase and endo-β-1,4-glucanase isozymes. These differences are discussed in relation to phylogeny and possible evolution to cope with the adoption of a terrestrial diet.
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  • 28
    Publication Date: 2019-07-17
    Description: Understanding the biogeochemical processes reg- ulating carbon cycling is central to mitigating atmospheric CO2 emissions. The role of living organisms has been accounted for, but the focus has traditionally been on contributions of plants and microbes. We develop the case that fully ‘‘animating’’ the carbon cycle requires broader consideration of the functional role of animals in mediating biogeochemical processes and quanti- fication of their effects on carbon storage and exchange among terrestrial and aquatic reservoirs and the atmosphere. To encourage more hypothesis-driven experimental research that quantifies animal effects we discuss the mecha- nisms by which animals may affect carbon ex- changes and storage within and among ecosystems and the atmosphere. We illustrate how those mechanisms lead to multiplier effects whose magnitudes may rival those of more tra- ditional carbon storage and exchange rate esti- mates currently used in the carbon budget. Many animal species are already directly managed. Thus improved quantitative understanding of their influence on carbon budgets may create oppor- tunity for management and policy to identify and implement new options for mitigating CO2 re- lease at regional scales.
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  • 29
    Publication Date: 2014-04-15
    Description: Why a chapter on Perspectives and Integration in SOLAS Science in this book? SOLAS science by its nature deals with interactions that occur: across a wide spectrum of time and space scales, involve gases and particles, between the ocean and the atmosphere, across many disciplines including chemistry, biology, optics, physics, mathematics, computing, socio-economics and consequently interactions between many different scientists and across scientific generations. This chapter provides a guide through the remarkable diversity of cross-cutting approaches and tools in the gigantic puzzle of the SOLAS realm. Here we overview the existing prime components of atmospheric and oceanic observing systems, with the acquisition of ocean–atmosphere observables either from in situ or from satellites, the rich hierarchy of models to test our knowledge of Earth System functioning, and the tremendous efforts accomplished over the last decade within the COST Action 735 and SOLAS Integration project frameworks to understand, as best we can, the current physical and biogeochemical state of the atmosphere and ocean commons. A few SOLAS integrative studies illustrate the full meaning of interactions, paving the way for even tighter connections between thematic fields. Ultimately, SOLAS research will also develop with an enhanced consideration of societal demand while preserving fundamental research coherency. The exchange of energy, gases and particles across the air-sea interface is controlled by a variety of biological, chemical and physical processes that operate across broad spatial and temporal scales. These processes influence the composition, biogeochemical and chemical properties of both the oceanic and atmospheric boundary layers and ultimately shape the Earth system response to climate and environmental change, as detailed in the previous four chapters. In this cross-cutting chapter we present some of the SOLAS achievements over the last decade in terms of integration, upscaling observational information from process-oriented studies and expeditionary research with key tools such as remote sensing and modelling. Here we do not pretend to encompass the entire legacy of SOLAS efforts but rather offer a selective view of some of the major integrative SOLAS studies that combined available pieces of the immense jigsaw puzzle. These include, for instance, COST efforts to build up global climatologies of SOLAS relevant parameters such as dimethyl sulphide, interconnection between volcanic ash and ecosystem response in the eastern subarctic North Pacific, optimal strategy to derive basin-scale CO2 uptake with good precision, or significant reduction of the uncertainties in sea-salt aerosol source functions. Predicting the future trajectory of Earth’s climate and habitability is the main task ahead. Some possible routes for the SOLAS scientific community to reach this overarching goal conclude the chapter.
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  • 30
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    In:  EPIC3The Mediterranean Sea: Its history and present challenges, The Mediterranean Sea: Its history and present challenges, Springer, pp. 319-339, ISBN: 978-94-007-6704-1
    Publication Date: 2014-04-15
    Description: Mussels Mytilus galloprovincialis have been used as model bivalves to study the impacts of global warming on their physiological performance in Themaikos Gulf, North Greece. The studies have been conducted under laboratory and field conditions for more than 6 years and focused on the biochemical, metabolic, physiological and energetic responses of M. galloprovincialis to increases in the ambient temperature. Here we summarize the findings concerning the responses of mussels to environmental temperature, present an integrated model of their physiological performance during thermal stress and discuss these findings in the light of the predicted temperature changes in the Thermaikos Gulf from the regional climate trends and the mean global temperature projections for the period 1990–2100 based on IS92 emission scenarios of the Intergovernmental Panel for Climate Change (IPCC). Our findings indicate that mussels in Themaikos Gulf currently face the temperatures close to their upper thermal limits, especially during the summer, and thus are likely vulnerably to any further increase in the temperature such as expected during the global warming
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  • 31
    Publication Date: 2015-01-05
    Description: Symbiotic dinoflagellates of the genus Symbiodinium, also called zooxanthellae, are found in association with a wide diversity of shallow-water anthozoans. The Symbiodinium genus includes numerous lineages, also referred to as clades or phylotypes, as well as a wide diversity of genetic sub-clades and sub-phylotypes. There are few studies characterizing the genetic diversity of zooxanthellae in Mediterranean anthozoans. In this study, we included anthozoans from the Western Mediterranean Sea and by means of internal transcriber (ITS) and large sub-unit (LSU) rRNA markers we corroborate what has been previously identified, demonstrating that phylotype “Temperate A” is very common among host Cnidaria in this basin. Our finding of fixed differences in ITS and LSU markers that correspond to different host taxa, indicate that this clade may comprise several closely-related species. Previous studies have reported the occurrence of Symbiodinium psygmophilum (formerly subclade B2) associated with Oculina patagonica and Cladocora caespitosa in the Eastern Mediterranean. Here, we identify this association in O. patagonica from the Western Mediterranean but not in C. caespitosa, suggesting some differences in symbiotic combinations between the Western and Eastern Mediterranean Basins.
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  • 32
    Publication Date: 2022-05-25
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Climatic Change 121 (2013): 381-395, doi:10.1007/s10584-013-0873-6.
    Description: Anthropogenic climate change has triggered impacts on natural and human systems world-wide, yet the formal scientific method of detection and attribution has been only insufficiently described. Detection and attribution of impacts of climate change is a fundamentally cross-disciplinary issue, involving concepts, terms, and standards spanning the varied requirements of the various disciplines. Key problems for current assessments include the limited availability of long-term observations, the limited knowledge on processes and mechanisms involved in changing environmental systems, and the widely different concepts applied in the scientific literature. In order to facilitate current and future assessments, this paper describes the current conceptual framework of the field and outlines a number of conceptual challenges. Based on this, it proposes workable cross-disciplinary definitions, concepts, and standards. The paper is specifically intended to serve as a baseline for continued development of a consistent cross-disciplinary framework that will facilitate integrated assessment of the detection and attribution of climate change impacts.
    Description: Modeling Program of the Office of Biological and Environmental Research in the Department of Energy Office of Science under contract number DE-AC02-05CH11231. GH was supported by a grant from the German Ministry for Education and Research.
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  • 33
    Publication Date: 2022-05-25
    Description: Author Posting. © The Authors, 2014. This article is posted here by permission of The Royal Astronomical Society for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 197 (2014): 697-704, doi:10.1093/gji/ggu048.
    Description: After the 1960 M9.5 Valdivia, Chile earthquake, three types of geodetic observations were made during four time periods at nearby locations. These post-seismic observations were previously explained by post-seismic afterslip on the downdip extension of the 1960 rupture plane. In this study, we demonstrate that the post-seismic observations can be explained alternatively by volumetric viscoelastic relaxation of the asthenosphere mantle. In searching for the best-fitting viscosity model, we invert for two variables, the thickness of the elastic lithosphere, He, and the effective Maxwell decay time of the asthenosphere mantle, TM, assuming a 100-km-thick asthenosphere mantle. The best solutions to fit the observations in four sequential time periods, 1960–1964, 1960–1968, 1965–1973 and 1980–2010, each yield a similar He value of about 65 km but significantly increasing TM values of 0.7, 6, 10 and 80 yr, respectively. We calculate the corresponding viscoelastic Coulomb stress increase since 1960 on the future rupture plane of the 2010 M8.8 Maule, Chile earthquake. The calculated viscoelastic stress increase on the 2010 rupture plane varies gradually from 13.1 bars at the southern end to 0.1 bars at the northern end. In contrast, the stress increase caused by an afterslip model has a similar spatial distribution but slightly smaller values of 0.1–3.2 bars on the 2010 rupture plane.
    Description: This work was supported by a MIT/WHOI Joint Program Student Fellowship and a Graduate Student Fellowship from the WHOI Deep Ocean Exploration Institute (MD), as well as NSF Grant OCE-1141785 and a Deerbrook Foundation Award (JL).
    Keywords: Seismic cycle ; Transient deformation ; Seismicity and tectonics ; Subduction zone processes ; Dynamics: seismotectonics ; South America
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  • 34
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    In:  EPIC3Integrated Analysis of Interglacial Climate Dynamics (INTERDYNAMIC), Integrated Analysis of Interglacial Climate Dynamics (INTERDYNAMIC), Heidelberg, Springer, pp. 19-23, ISBN: 978-3-319-00693-2, ISSN: 2191-589X
    Publication Date: 2015-06-05
    Description: Studying the climate dynamics of past interglacials (IGs) may help to better assess the anthropogenically influenced dynamics of the current IG, the Holocene. We select IG sections from the longest ice core archive, EPICA Dome C (EDC), which covers the past 800 thousand years, and study as well several long, high-resolution marine sediment records. We analyze records of Antarctic temperature, radiative forcing (greenhouse gases and other factors), and sea-surface temperature (SST). Change-point regressions inform about longer-term climate changes and trends within IGs. Comparing trends in temperature with trends in forcing allows inference of longer-term IG climate sensitivities. Results from many records indicate deviations from a “Holocene climate optimum”. IG sensitivities are found to be comparable to estimates for the instrumental period; warming or cooling phases during Marine Isotope Stage (MIS) 5 or 11 do not show significant differences in climate sensitivity.
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  • 35
    Publication Date: 2022-05-26
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Genome Biology and Evolution 5 (2013): 2368-2381, doi:10.1093/gbe/evt179.
    Description: The dinoflagellates are an evolutionarily and ecologically important group of microbial eukaryotes. Previous work suggests that horizontal gene transfer (HGT) is an important source of gene innovation in these organisms. However, dinoflagellate genomes are notoriously large and complex, making genomic investigation of this phenomenon impractical with currently available sequencing technology. Fortunately, de novo transcriptome sequencing and assembly provides an alternative approach for investigating HGT. We sequenced the transcriptome of the dinoflagellate Alexandrium tamarense Group IV to investigate how HGT has contributed to gene innovation in this group. Our comprehensive A. tamarense Group IV gene set was compared with those of 16 other eukaryotic genomes. Ancestral gene content reconstruction of ortholog groups shows that A. tamarense Group IV has the largest number of gene families gained (314–1,563 depending on inference method) relative to all other organisms in the analysis (0–782). Phylogenomic analysis indicates that genes horizontally acquired from bacteria are a significant proportion of this gene influx, as are genes transferred from other eukaryotes either through HGT or endosymbiosis. The dinoflagellates also display curious cases of gene loss associated with mitochondrial metabolism including the entire Complex I of oxidative phosphorylation. Some of these missing genes have been functionally replaced by bacterial and eukaryotic xenologs. The transcriptome of A. tamarense Group IV lends strong support to a growing body of evidence that dinoflagellate genomes are extraordinarily impacted by HGT.
    Description: J.H.W. was supported by the NSF IGERT Program in Comparative Genomics at the University of Arizona (grant number DGE-0654435). This work was supported by grants from the National Science Foundation (grant numbers OCE-0723498, EF-0732440) and funding provided by the BIO5 Institute at the University of Arizona to J.D.H.
    Keywords: Gene innovation ; Alexandrium tamarense Group IV ; Phylogenetic profile ; Phylogenomics ; De novo transcriptome assembly ; Mitochondrial metabolism
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  • 36
    Publication Date: 2022-05-26
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Environmental Biology of Fishes 97 (2014): 881-896, doi:10.1007/s10641-013-0189-4.
    Description: Age and growth estimates for the dusky shark, Carcharhinus obscurus, were derived from vertebral centra collected in the northwestern Atlantic Ocean. Sample collection spanned the years prior to and following the implementation of management measures (1963–2010). Growth was compared pre- and post- population depletion and pre- and post- management to investigate the possibility of density-mediated shifts in age and growth parameters over time. There was no evidence of difference between periods for either sex. Additionally, bomb radiocarbon dating was used to determine the periodicity of band pair formation. Results support the traditional interpretation of annual band pairs up to approximately 11 years of age. After this time, vertebral counts considerably underestimate true age. Maximum validated ages were estimated to be between 38 and 42 years of age (an increase of 15 to 19 years over the band count estimates), confirming longevity to at least 42 years of age. Growth curves estimated using only validated data were compared to those generated using band pair counts. Logistic growth parameters derived from validated vertebral length-at-age data were L ∞  = 261.5 cm FL, L o  = 85.5 cm, t o  = 4.89 year and g = 0.15 year−1 for the sexes combined. Revised estimates of age at maturity were 17.4 years for males and 17.6 years for females.
    Keywords: Dusky shark ; Age and growth ; Elasmobranch ; Vertebrae ; Bomb radiocarbon ; Validation
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  • 37
    Publication Date: 2022-05-26
    Description: Author Posting. © Author, 2014. This article is posted here by permission of The Royal Astronomical Society for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 198 (2014): 622-636, doi: 10.1093/gji/ggu121.
    Description: The robust statistical model of a Gaussian core contaminated by outlying data that underlies robust estimation of the magnetotelluric (MT) response function has been re-examined. The residuals from robust estimators are systematically long tailed compared to a distribution based on the Gaussian, and hence are inconsistent with the robust model. Instead, MT data are pervasively described by the alpha stable distribution family whose variance and sometimes mean are undefined. A maximum likelihood estimator (MLE) that exploits the stable nature of MT data is formulated, and its two-stage implementation in which stable parameters are first fit to the data and then the MT responses are solved for is described. The MLE is shown to be inherently robust, but differs from the conventional robust estimator because it is based on a model derived from the data, while robust estimators are ad hoc, being based on the robust model that is inconsistent with actual data. Propriety versus impropriety of the complex MT response was investigated, and a likelihood ratio test for propriety and its null distribution was established. The Cramér-Rao lower bounds for the covariance matrix of proper and improper MT responses were specified. The MLE was applied to exemplar long period and broad-band data sets from South Africa. Both are shown to be significantly stably distributed using the Kolmogorov–Smirnov goodness of fit and Ansari-Bradley non-parametric dispersion tests. Impropriety of the MT responses at both sites is pervasive, hence the improper Cramér-Rao bound was used to estimate the MLE covariance. The MLE is shown to be nearly unbiased and well described by a Gaussian distribution based on bootstrap simulation. The MLE was compared to a conventional robust estimator, establishing that the standard errors of the former are systematically smaller than for the latter and that the standardized differences between them exhibit excursions that are both too frequent and too large to be described by a Gaussian model. This is ascribed to pervasive bias of the robust estimator that is to some degree obscured by their systematically large confidence bounds. Finally, a series of topics for further investigation is proposed.
    Description: This work was supported by NSF grant EAR0809074.
    Keywords: Time series analysis ; Numerical approximations and analysis ; Fractals and multifractals ; Probability distributions ; Magnetotellurics
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  • 38
    Publication Date: 2022-05-26
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Plankton Research 36 (2014): 943-955, doi:10.1093/plankt/fbu029.
    Description: The mechanisms by which phytoplankton cope with stressors in the marine environment are neither fully characterized nor understood. As viruses are the most abundant entities in the global ocean and represent a strong top-down regulator of phytoplankton abundance and diversity, we sought to characterize the cellular response of two marine haptophytes to virus infection in order to gain more knowledge about the nature and diversity of microalgal responses to this chronic biotic stressor. We infected laboratory cultures of the haptophytes Haptolina ericina and Phaeocystis pouchetii with CeV-01B or PpV-01B dsDNA viruses, respectively, and assessed the extent to which host cellular responses resemble programmed cell death (PCD) through the activation of diagnostic molecular and biochemical markers. Pronounced DNA fragmentation and activation of cysteine aspartate-specific proteases (caspases) were only detected in virus-infected cultures of these phytoplankton. Inhibition of host caspase activity by addition of the pan-caspase inhibitor z-VAD-fmk did not impair virus production in either host–virus system, differentiating it from the Emiliania huxleyi-Coccolithovirus model of haptophyte–virus interactions. Nonetheless, our findings point to a general conservation of PCD-like activation during virus infection in ecologically diverse haptophytes, with the subtle heterogeneity of cell death biochemical responses possibly exerting differential regulation on phytoplankton abundance and diversity.
    Description: Funding to J.L.R, R.-A.S. and A.L. was provided by the Norwegian Research Council for the “VIPMAP” (nr. 186142) and “HAPTODIV” (nr. 190307) projects, and by the European Research Council Advanced Grant ERC-AG-LS8 “Microbial Network Organisation” (MINOS, project number 250254). J.L.R. received a FRIBIO overseas research fellowship from the Norwegian Research Council. K.D.B. and B.V.M. were supported by funding from the United States National Science Foundation (OCE-1061883).
    Keywords: Caspase ; DNA fragmentation ; IETD ; Phycodnaviridae ; z-VAD-fmk ; Haptophyte
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  • 39
    Publication Date: 2022-05-26
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Genome Biology and Evolution 6 (2014): 2210-2217, doi:10.1093/gbe/evu177.
    Description: The alpha subunits of voltage-gated calcium channels (Cavs) are large transmembrane proteins responsible for crucial physiological processes in excitable cells. They are assisted by three auxiliary subunits that can modulate their electrical behavior. Little is known about the evolution and roles of the various subunits of Cavs in nonbilaterian animals and in nonanimal lineages. For this reason, we mapped the phyletic distribution of the four channel subunits and reconstructed their phylogeny. Although alpha subunits have deep evolutionary roots as ancient as the split between plants and opistokonths, beta subunits appeared in the last common ancestor of animals and their close-relatives choanoflagellates, gamma subunits are a bilaterian novelty and alpha2/delta subunits appeared in the lineage of Placozoa, Cnidaria, and Bilateria. We note that gene losses were extremely common in the evolution of Cavs, with noticeable losses in multiple clades of subfamilies and also of whole Cav families. As in vertebrates, but not protostomes, Cav channel genes duplicated in Cnidaria. We characterized by in situ hybridization the tissue distribution of alpha subunits in the sea anemone Nematostella vectensis, a nonbilaterian animal possessing all three Cav subfamilies common to Bilateria. We find that some of the alpha subunit subtypes exhibit distinct spatiotemporal expression patterns. Further, all six sea anemone alpha subunit subtypes are conserved in stony corals, which separated from anemones 500 MA. This unexpected conservation together with the expression patterns strongly supports the notion that these subtypes carry unique functional roles.
    Keywords: Voltage-gated calcium channel ; Ion channel ; Cnidaria ; Nematostella vectensis ; Evolution of nervous system
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  • 40
    Publication Date: 2022-05-26
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ocean Dynamics 64 (2014): 1767-1781, doi:10.1007/s10236-014-0781-y.
    Description: Locations along the inner-continental shelf offshore of Fire Island, NY, are characterized by a series of shoreface-connected ridges (SFCRs). These sand ridges have approximate dimensions of 10 km in length, 3 km spacing, and up to ∼8 m ridge to trough relief and are oriented obliquely at approximately 30° clockwise from the coastline. Stability analysis from previous studies explains how sand ridges such as these could be formed and maintained by storm-driven flows directed alongshore with a key maintenance mechanism of offshore deflected flows over ridge crests and onshore in the troughs. We examine these processes both with a limited set of idealized numerical simulations and analysis of observational data. Model results confirm that alongshore flows over the SFCRs exhibit offshore veering of currents over the ridge crests and onshore-directed flows in the troughs, and demonstrate the opposite circulation pattern for a reverse wind. To further investigate these maintenance processes, oceanographic instruments were deployed at seven sites on the SFCRs offshore of Fire Island to measure water levels, ocean currents, waves, suspended sediment concentrations, and bottom stresses from January to April 2012. Data analysis reveals that during storms with winds from the northeast, the processes of offshore deflection of currents over ridge crests and onshore in the troughs were observed, and during storm events with winds from the southwest, a reverse flow pattern over the ridges occurred. Computations of suspended sediment fluxes identify periods that are consistent with SFCR maintenance mechanisms. Alongshore winds from the northeast drove fluxes offshore on the ridge crest and onshore in the trough that would tend to promote ridge maintenance. However, alongshore winds from the southwest drove opposite circulations. The wind fields are related to different storm types that occur in the region (low-pressure systems, cold fronts, and warm fronts). From the limited data set, we identify that low-pressure systems drive sediment fluxes that tend to promote stability and maintain the SFCRs while cold front type storms appear to drive circulations that are in the opposite sense and may not be a supporting mechanism for ridge maintenance.
    Description: This research was funded by the U.S. Geological Survey, Coastal and Marine Geology Program, and conducted by the Coastal Change Processes Project.
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  • 41
    Publication Date: 2022-05-26
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Natural Hazards 74 (2014): 123-142, doi:10.1007/s11069-014-1294-1.
    Description: A probabilistic technique is developed to assess the hazard from meteotsunamis. Meteotsunamis are unusual sea-level events, generated when the speed of an atmospheric pressure or wind disturbance is comparable to the phase speed of long waves in the ocean. A general aggregation equation is proposed for the probabilistic analysis, based on previous frameworks established for both tsunamis and storm surges, incorporating different sources and source parameters of meteotsunamis. Parameterization of atmospheric disturbances and numerical modeling is performed for the computation of maximum meteotsunami wave amplitudes near the coast. A historical record of pressure disturbances is used to establish a continuous analytic distribution of each parameter as well as the overall Poisson rate of occurrence. A demonstration study is presented for the northeast U.S. in which only isolated atmospheric pressure disturbances from squall lines and derechos are considered. For this study, Automated Surface Observing System stations are used to determine the historical parameters of squall lines from 2000 to 2013. The probabilistic equations are implemented using a Monte Carlo scheme, where a synthetic catalog of squall lines is compiled by sampling the parameter distributions. For each entry in the catalog, ocean wave amplitudes are computed using a numerical hydrodynamic model. Aggregation of the results from the Monte Carlo scheme results in a meteotsunami hazard curve that plots the annualized rate of exceedance with respect to maximum event amplitude for a particular location along the coast. Results from using multiple synthetic catalogs, resampled from the parent parameter distributions, yield mean and quantile hazard curves. Further refinements and improvements for probabilistic analysis of meteotsunamis are discussed.
    Keywords: Meteotsunami ; Probabilistic analysis ; Squall line ; Derecho ; Shallow-water wave ; Linear long wave
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  • 42
    Publication Date: 2022-05-26
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Earth, Planets and Space 66 (2014): 81, doi:10.1186/1880-5981-66-81.
    Description: Investigation of olivine-hosted melt inclusions provides information about the abundance of volatile elements that are often lost during subaerial eruptions of lavas. We have measured the abundances of H2O, CO2, F, Cl, and S as well as Pb isotopes in 29 melt inclusions in the scoria of the 1686 eruption of the Iwate volcano, a frontal-arc volcano in the northeast Japan arc. Pb Isotope compositions identify that Iwate magma is derived from a mixture of depleted mantle, subducted basalt, and sediment. Systematics of F in comparison to MORB and other arc magma indicates that (1) the slab surface temperature must be among the lowest on Earth and (2) hydrous minerals, such as amphibole, humites, and/or mica, must be present as residual phases during the dehydration of the slab.
    Description: The authors acknowledge financial support from the French Agence Nationale de la Recherche (projects: SlabFlux grant no. ANR 2009 Blanc 0338 and DegazMag, grant no. ANR 2011 Blanc SIMI 5-6 003). This research was financed by the French Government Laboratory of Excellence initiative no. ANR-10-LABX-0006, the Région Auvergne, and the European Regional Development Fund.
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  • 43
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    In:  EPIC3Earth System Science: Bridging the Gaps between Disciplines Perspectives from a Multi-disciplinary Helmholtz Research School, SpringerBriefs in Earth System Science, Heidelberg, Springer, 138 p., pp. 42-45, ISBN: ISBN 978-3-642-32234
    Publication Date: 2019-08-16
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  • 44
    Publication Date: 2017-01-16
    Description: Early life stages of marine crustaceans respond sensitively to elevated seawater PCO2. However, the underlying physiological mechanisms have not been studied well. We therefore investigated the effects of elevated seawater PCO2 on oxygen consumption, dry weight, elemental composition, median developmental time (MDT) and mortality in zoea I larvae of the spider crab Hyas araneus (Svalbard 79°N/11°E; collection, May 2009; hatch, December 2009). At the time of moulting, oxygen consumption rate had reached a steady state level under control conditions. In contrast, elevated seawater PCO2 caused the metabolic rate to rise continuously leading to a maximum 1.5-fold increase beyond control level a few days before moulting into the second stage (zoea II), followed by a pronounced decrease. Dry weight of larvae reared under high CO2 conditions was lower than in control larvae at the beginning of the moult cycle, yet this difference had disappeared at the time of moulting. MDT of zoea I varied between 45 ± 1 days under control conditions and 42 ± 2 days under the highest seawater CO2 concentration. The present study indicates that larval development under elevated seawater PCO2 levels results in higher metabolic costs during premoulting events in zoea I. However, H. araneus zoea I larvae seem to be able to compensate for higher metabolic costs as larval MDT and survival was not affected by elevated PCO2 levels.
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  • 45
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    Oxford University Press
    In:  EPIC3Journal of Experimental Botany, Oxford University Press, ISSN: 0022-0957
    Publication Date: 2019-07-17
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  • 46
    Publication Date: 2017-04-04
    Description: A temporary seismic network composed of 11 stations was installed in the city of Potenza (Southern Italy) to record local and regional seismicity within the context of a national project funded by the Italian Department of Civil Protection (DPC). Some stations were moved after a certain time in order to increase the number of measurement points, leading to a total of 14 sites within the city by the end of the experiment. Recordings from 26 local earthquakes (Ml 2.2−3.8 ) were analyzed to compute the site responses at the 14 sites by applying both reference and non-reference site techniques. Furthermore, the Spectral Intensity (SI) for each local earthquake, as well as their ratios with respect to the values obtained at a reference site, were also calculated. In addition, a field survey of 233 single station noise measurements within the city was carried out to increase the information available at localities different from the 14 monitoring sites. By using the results of the correlation analysis between the horizontal-to-vertical spectral ratios computed from noise recordings (NHV) at the 14 selected sites and those derived by the single station noise measurements within the town as a proxy, the spectral intensity correction factors for site amplification obtained from earthquake analysis were extended to the entire city area. This procedure allowed us to provide a microzonation map of the urban area that can be directly used when calculating risk scenarios for civil defence purposes. The amplification factors estimated following this approach show values increasing along the main valley toward east where the detrital and alluvial complexes reach their maximum thickness.
    Description: Published
    Description: 493-516
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: restricted
    Keywords: site effect ; seismic noise ; spectral intensity ; correlation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 47
    Publication Date: 2017-04-04
    Description: We present results of a multi-temporal analysis of airborne LiDAR data collected between 2006 and 2010 on the 3 km long active Montaguto landslide (Italy). Digital Terrain Models are constructed from data acquired on May 2006, July 2009, April 2010 and June 2010. The spatial distribution of selected morphometric parameters and the statistical analysis of the temporal variations of such parameters allow us to reconstruct the evolution of the landslide. We recognize zones of uplift and subsidence, estimate the volumes of removed or accumulated material, and determine the average rate of vertical and horizontal displacement. We also map the deformations structures and provide new insights on the sliding mechanisms. Zones in which the topographic features change due to handling/removal work are also analyzed. The approach proposed here provides new insight on the use of airborne LiDAR in the surveillance strategies of landslides and other gravity-controlled processes.
    Description: Published
    Description: 147-151
    Description: 1.10. TTC - Telerilevamento
    Description: 5.5. TTC - Sistema Informativo Territoriale
    Description: restricted
    Keywords: LiDAR ; Multi-temporal analysis ; Gravity processes ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 05. General::05.08. Risk::05.08.01. Environmental risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 48
    Publication Date: 2017-04-03
    Description: The Salina, Lipari, and Vulcano volcanic ridge and the surrounding sea sectors (Aeolian Archipelago, Southern Tyrrhenian Sea, Italy) are characterized by vents responsible for a recent (〈40 ka—1889/1890 AD) effusive and explosive subareal activity and repeated, 56 to 7 ka in age, submarine explosive eruptions from source areas located between Lipari and Vulcano. A spectral depth estimation of the magnetic bottom using a fractal method on aeromagnetic data from Vulcano, Lipari, and Salina volcanic ridge allows us to constrain the Curie isotherm depth. The elevated portion of the isotherm is between 2 and 3 km below Salina and Vulcano and about 1 km below Lipari. The Curie depth results in the context of other geological and geophysical evidence suggest that the rise of the Curie isotherm is mainly due to the occurrence of shallow heat sources such as magma ponds and associated hydrothermal systems. The short-wavelength magnetic anomaly field reflects magnetic contrasts from highly magnetized volcanic bodies, low-magnetization sediments, and hydrothermally altered rocks. Borehole temperature data verify the Curie temperature derived from the magnetic methods on the island of Vulcano.We conclude that the whole Vulcano, Lipari, and Salina volcanic ridge is active and should be monitored.
    Description: INGV
    Description: Published
    Description: article 710
    Description: 1.10. TTC - Telerilevamento
    Description: 3.3. Geodinamica e struttura dell'interno della Terra
    Description: 3.4. Geomagnetismo
    Description: 3.6. Fisica del vulcanismo
    Description: 5.4. Banche dati di geomagnetismo, aeronomia, clima e ambiente
    Description: JCR Journal
    Description: restricted
    Keywords: Magnetic spectral depths ; Curie temperature ; volcanism ; Aeolian Islands ; 04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks ; 04. Solid Earth::04.02. Exploration geophysics::04.02.04. Magnetic and electrical methods ; 04. Solid Earth::04.05. Geomagnetism::04.05.03. Global and regional models ; 04. Solid Earth::04.05. Geomagnetism::04.05.07. Rock magnetism ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.03. Heat generation and transport ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 49
    Publication Date: 2020-02-10
    Description: Approximately 1700 Pg of soil carbon (C) are stored in the northern circumpolar permafrost zone, more than twice as much C than in the atmosphere. The overall amount, rate, and form of C released to the atmosphere in a warmer world will influence the strength of the permafrost C feedback to climate change. We used a survey to quantify variability in the perception of the vulnerability of permafrost C to climate change. Experts were asked to provide quantitative estimates of permafrost change in response to four scenarios of warming. For the highest warming scenario (RCP 8.5), experts hypothesized that C release from permafrost zone soils could be 19–45 Pg C by 2040, 162–288 Pg C by 2100, and 381–616 Pg C by 2300 in CO2 equivalent using 100-year CH4 global warming potential (GWP). These values become 50 % larger using 20-year CH4 GWP, with a third to a half of expected climate forcing coming from CH4 even though CH4 was only 2.3 % of the expected C release. Experts projected that two-thirds of this release could be avoided under the lowest warming scenario (RCP 2.6). These results highlight the potential risk from permafrost thaw and serve to frame a hypothesis about the magnitude of this feedback to climate change. However, the level of emissions proposed here are unlikely to overshadow the impact of fossil fuel burning, which will continue to be the main source of C emissions and climate forcing.
    Repository Name: EPIC Alfred Wegener Institut
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  • 50
    Publication Date: 2019-07-16
    Description: Copepods can be associated with different kinds and different numbers of bacteria. This was already shown in the past with culture-dependent microbial methods or microscopy and more recently by using molecular tools. In our present study, we investigated the bacterial community of four frequently occurring copepod species, Acartia sp., Temora longicornis, Centropages sp. and Calanus helgolandicus from Helgoland Roads (North Sea) over a period of two years using DGGE (denaturing gradient gel electrophoresis) and subsequent sequencing of 16S-rDNA fragments. To complement the PCR-DGGE analyses, clone libraries of copepod samples from June 2007 and 208 were generated. Based on the DGGE banding patterns of the two years survey, we found no significant differences between the communities of distinct copepod species, nor did we find any seasonality. Overall, we identified 67 phylotypes (〉 97% similarity) falling into the bacterial phyla of Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. The most abundant phylotypes were affiliated to the Alphaproteobacteria. In comparison of PCR-DGGE and clone libraries, phylotypes of the Gammaproteobacteria dominated the clone libraries, whereas Alphaproteobacteria were most abundant in the PCR-DGGE analyses
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  • 51
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    In:  EPIC3Biodiversität und Klimawandel: Auswirkungen und Handlungsoptionen für den Naturschutz in Mitteleuropa, Springer, pp. 217-222, ISSN: ISBN 978-3-642-29691-8
    Publication Date: 2018-02-16
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  • 52
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    In:  EPIC3Geo-Marine Letters, Springer, 33(5), pp. 381-390, ISSN: 1432-1157
    Publication Date: 2019-07-16
    Description: Sediment thickness was evaluated on the western flank of the East Pacific Rise (EPR) at 45°S, based on high-resolution seismic data gathered during cruise 213/2 of R/V Sonne in 2011. Two zones with distinctly different sediment thickness were identified, separated by a transitional zone bordering a pseudo-fault. Sediment in the more distal zone 2 is almost twice as thick (~120 m) as in zone 1 close to the EPR. This is in contrast to the expected sedimentary column thickening with seafloor age and distance from the spreading axis. The younger of two seismic units detected within the sedimentary column (EPR-2) occurs mainly in the distal zone on crust older than 9 Ma, whereas on younger crust it is present only in small isolated bodies. Both sedimentary units drape the basement. The drape is interpreted to represent particle settling from suspension and a generally low regional primary productivity. The spatial variation in sediment thickness cannot be explained by existing models, and other processes considered in the present case are (1) higher productivity in the western sector of the survey area, where thicker sediments were observed (zone 2), (2) the formation of sediment drifts near basement highs (‘seamount effect’), due to flow of Lower Circumpolar Deep Water affecting sediment deposition, and (3) erosion and/or non-deposition of the younger EPR-2 unit, due to elevated bed shear stresses associated with eddies transferring kinetic energy to the seafloor
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  • 53
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    In:  EPIC3Earth System Science: Bridging the Gaps between Disciplines Perspectives from a Multi-disciplinary Helmholtz Research School, Heidelbert, Springer, 138 p., pp. 57-64, ISBN: ISBN 978-3-642-32234
    Publication Date: 2019-08-16
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  • 54
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    In:  EPIC3Earth System Science: Bridging the Gaps between Disciplines Perspectives from a Multi-disciplinary Helmholtz Research School, Heidelberg, Springer, 138 p., pp. 64-69, ISBN: ISBN 978-3-642-32234
    Publication Date: 2014-04-15
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  • 55
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    In:  EPIC3Earth System Science: Bridging the Gaps between Disciplines Perspectives from a Multi-disciplinary Helmholtz Research School, Heidelberg, Springer, 138 p., pp. 74-79, ISBN: ISBN 978-3-642-32234
    Publication Date: 2014-04-15
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  • 56
    Publication Date: 2021-07-19
    Description: The summer water balance of a typical Siberian polygonal tundra catchment is investigated in order to identify the spatial and temporal dynamics of its main hydrological processes. The results show that, besides precipitation and evapotranspiration, lateral flow considerably influences the site-specific hydrological conditions. The prominent microtopography of the polygonal tundra strongly controls lateral flow and storage behaviour of the investigated catchment. Intact rims of low-centred polygons build hydrological barriers, which release storage water later in summer than polygons with degraded rims and troughs above degraded ice wedges. The barrier function of rims is strongly controlled by soil thaw, which opens new subsurface flow paths and increases subsurface hydrological connectivity. Therefore, soil thaw dynamics determine the magnitude and timing of subsurface outflow and the redistribution of storage within the catchment. Hydraulic conductivities in the elevated polygonal rims sharply decrease with the transition from organic to mineral layers. This interface causes a rapid shallow subsurface drainage of rainwater towards the depressed polygon centres and troughs. The re-release of storage water from the centres through deeper and less conductive layers helps maintain a high water table in the surface drainage network of troughs throughout the summer.
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  • 57
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    In:  EPIC3The Mediterranean Sea: Its history and present challenges, The Mediterranean Sea: Its hisory and present challenges, Springer, pp. 499-504
    Publication Date: 2016-02-13
    Repository Name: EPIC Alfred Wegener Institut
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  • 58
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    In:  EPIC3Earth System Science: Bridging the Gaps between Disciplines Perspectives from a Multi-disciplinary Helmholtz Research School, Heidelberg, Springer, 138 p., pp. 70-74, ISBN: ISBN 978-3-642-32234
    Publication Date: 2014-04-15
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  • 59
    Publication Date: 2019-07-16
    Description: In contemporary ocean science, modeling systems that integrate understanding of complex multiscale phenomena and utilize efficient numerics are paramount. Many of today's fundamental ocean science questions involve multiple scales and multiple dynamics. A new generation of modeling systems would allow to study such questions quantitatively by being less restrictive dynamically and more efficient numerically than more traditional systems.
    Repository Name: EPIC Alfred Wegener Institut
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  • 60
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    American Physical Society
    In:  EPIC3Physical Review E, American Physical Society, 88(6), ISSN: 1539-3755
    Publication Date: 2018-02-16
    Description: In this study we model population dynamics in a three-species food web with heterogeneous resources and intraguild predation by using a nonspatial Lotka-Volterra system with a density-dependent interaction of resource items. The model consists of two predators with an intraguild predation (IGP) relation competing for a common resource. The resource is subdivided into subpopulations of different quality that are distinguished by grazing rates of the two predators, contact rates between subpopulations and mortality rates. The proposed system describes an exchange of traits between species from distinct subpopulations by using a species interaction term. In particular, we examine the percentage of stable coexistence solutions versus resource carrying capacity and contact rates between distinct resource pools. We also present a numerical comparison of the percentage of stable food webs found for different numbers of subpopulations. While at high enrichment no stable coexistence was found in the IGP system with a single resource, our model predicts a stable coexistence of two IGP-related predators and resources at high and intermediate enrichment already at a low contact rate between subpopulations.
    Repository Name: EPIC Alfred Wegener Institut
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  • 61
    Publication Date: 2019-07-16
    Description: In this experimental study, we compared the embryonic respiration rate in air and water of six East African sesarmid species with intertidal, supratidal and arboreal habits, to highlight possible adaptations in embryonic metabolism to their different lifestyles. The embryos of all analysed crabs showed bimodal respiration, but we did not find a trend towards an enhanced embryonic oxygen uptake in air from the intertidal to the arboreal and supratidal species. However, the late-stage embryos of the most land-adapted species, Chiromantes spp., showed an enhanced metabolism when immersed in sea water that we interpreted as an adaptive recovery mechanism to cope with the storage of by-products due to marine-based metabolic pathways during long emersion periods. Thus, we showed that the embryos of land-adapted species, although still strongly water dependent, are well adapted to semi-terrestrial habitats and represent a minor limiting factor for females, which are not restricted in their emersion period by the oxygen requirements of their embryos.
    Repository Name: EPIC Alfred Wegener Institut
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  • 62
    Publication Date: 2017-06-05
    Description: The endemic Antarctic brown macroalga Desmarestia anceps colonizes the subtidal between 5 and 30 m in Potter Cove on King George Island (South Shetland Islands, Antarctica). Experiments were conducted to study photosynthetic activities, antioxidative enzymes and UV tolerance of field-grown individuals with respect to the light histories along different subtidal positions. Individuals collected from the upper (5.5 m) and mid-subtidal (9.0 m) are characterized by high maximum electron transport rates (ETRmax) measured by PAM-fluorometry and high activities of superoxide dismutase (SOD) supported by considerable activities of glutathione reductase. Individuals of this species from the upper subtidal are able to tolerate high irradiances of UV-B radiation because its photosynthetic apparatus is putatively well protected by phlorotannins. In contrast, individuals from lower subtidal positions (13.5 and 15.5 m) showed an opposite trend: lower ETRmax and SOD activities as well as a lower UV tolerance of photosynthesis. Moreover, a non-denaturing polyacrylamide gel electrophoresis (native PAGE) of a partially purified crude extract reveals that D. anceps has probably six isoforms of SOD. These intra-specific patterns imply a high phenotypical plasticity of D. anceps with respect to its photosynthesis and photoprotective mechanisms. Overall, photosynthesis, UV tolerance and antioxidative potential are highly regulated in D. anceps corresponding to the respective light regimes along its natural growth sites.
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  • 63
    Publication Date: 2022-05-25
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Conservation Physiology 1 (2013): cot006, doi:10.1093/conphys/cot006.
    Description: Large whales are subjected to a variety of conservation pressures that could be better monitored and managed if physiological information could be gathered readily from free-swimming whales. However, traditional approaches to studying physiology have been impractical for large whales, because there is no routine method for capture of the largest species and there is presently no practical method of obtaining blood samples from free-swimming whales. We review the currently available techniques for gathering physiological information on large whales using a variety of non-lethal and minimally invasive (or non-invasive) sample matrices. We focus on methods that should produce information relevant to conservation physiology, e.g. measures relevant to stress physiology, reproductive status, nutritional status, immune response, health, and disease. The following four types of samples are discussed: faecal samples, respiratory samples (‘blow’), skin/blubber samples, and photographs. Faecal samples have historically been used for diet analysis but increasingly are also used for hormonal analyses, as well as for assessment of exposure to toxins, pollutants, and parasites. Blow samples contain many hormones as well as respiratory microbes, a diverse array of metabolites, and a variety of immune-related substances. Biopsy dart samples are widely used for genetic, contaminant, and fatty-acid analyses and are now being used for endocrine studies along with proteomic and transcriptomic approaches. Photographic analyses have benefited from recently developed quantitative techniques allowing assessment of skin condition, ectoparasite load, and nutritional status, along with wounds and scars from ship strikes and fishing gear entanglement. Field application of these techniques has the potential to improve our understanding of the physiology of large whales greatly, better enabling assessment of the relative impacts of many anthropogenic and ecological pressures.
    Description: This work was supported by the United States Office of Naval Research (award #N000141110435 to K.E.H., award #N000141110540 to R.M.R., and award #N0001412WX20890 to L.C.Y. and C.E.D.); the United Kingdom Natural Environmental Research Council (supporting A.J.H.); the National Center for Research Resources, a component of the United States National Institutes of Health (NIH; supporting C.E.D.); the NIH Roadmap for Medical Research (UL1 RR024146 supporting C.E.D.); The Hartwell Foundation (supporting C.E.D.) and the 2012 Marine Mammal Breath Workshop, which was funded by the National Oceanic and Atmospheric Administration’s Marine Mammal Health and Stranding Response Program.
    Keywords: Blow ; Biopsy dart ; Cetacea ; Faecal samples ; Non-invasive ; Visual health assessment
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  • 64
    Publication Date: 2022-05-25
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecosystems 16 (2013): 1550-1564, doi:10.1007/s10021-013-9701-0.
    Description: We examined controls of benthic dinitrogen (N2) fixation and primary production in oligotrophic lakes in Arctic Alaska, Toolik Field Station (Arctic Long-Term Ecological Research Site). Primary production in many oligotrophic lakes is limited by nitrogen (N), and benthic processes are important for whole-lake function. Oligotrophic lakes are increasingly susceptible to low-level, non-point source nutrient inputs, yet the effects on benthic processes are not well understood. This study examines the results from a whole-lake fertilization experiment in which N and P were added at a relatively low level (4 times natural loading) in Redfield ratio to a shallow (3 m) and a deep (20 m) oligotrophic lake. The two lakes showed similar responses to fertilization: benthic primary production and respiration (each 50–150 mg C m−2 day−1) remained the same, and benthic N2 fixation declined by a factor of three- to fourfold by the second year of treatment (from ~0.35 to 0.1 mg N m−2 day−1). This showed that the response of benthic N2 fixation was de-coupled from the nutrient limitation status of benthic primary producers and raised questions about the mechanisms, which were examined in separate laboratory experiments. Bioassay experiments in intact cores also showed no response of benthic primary production to added N and P, but contrasted with the whole-lake experiment in that N2 fixation did not respond to added N, either alone or in conjunction with P. This inconsistency was likely a result of nitrogenase activity of existing N2 fixers during the relative short duration (9 days) of the bioassay experiment. N2 fixation showed a positive saturating response when light was increased in the laboratory, but was not statistically related to ambient light level in the field, leading us to conclude that light limitation of the benthos from increasing water-column production was not important. Thus, increased N availability in the sediments through direct uptake likely caused a reduction in N2 fixation. These results show the capacity of the benthos in oligotrophic systems to buffer the whole-system response to nutrient addition by the apparent ability for significant nutrient uptake and the rapid decline in N2 fixation in response to added nutrients. Reduced benthic N2 fixation may be an early indicator of a eutrophication response of lakes which precedes the transition from benthic to water-column-dominated systems.
    Description: This project was supported by NSF-OPP 9732281, NSF-DEB 9810222, NSF-DEB 0423385, and by a Doctoral Dissertation Improvement Grant NSF-DEB 0206173. Additional funding was provided by the Small Grants Program through the NSF-IGERT Program in Biogeochemistry and Environmental Change at Cornell University.
    Keywords: Benthic ; Nitrogen fixation ; Primary production ; Oligotrophic ; Arctic ; Toolik
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  • 65
    Publication Date: 2022-05-25
    Description: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nucleic Acids Research 40 (2012): W82-W87, doi:10.1093/nar/gks418.
    Description: Amplicon sequencing of the hypervariable regions of the small subunit ribosomal RNA gene is a widely accepted method for identifying the members of complex bacterial communities. Several rRNA gene sequence reference databases can be used to assign taxonomic names to the sequencing reads using BLAST, USEARCH, GAST or the RDP classifier. Next-generation sequencing methods produce ample reads, but they are short, currently ∼100–450 nt (depending on the technology), as compared to the full rRNA gene of ∼1550 nt. It is important, therefore, to select the right rRNA gene region for sequencing. The primers should amplify the species of interest and the hypervariable regions should differentiate their taxonomy. Here, we introduce TaxMan: a web-based tool that trims reference sequences based on user-selected primer pairs and returns an assessment of the primer specificity by taxa. It allows interactive plotting of taxa, both amplified and missed in silico by the primers used. Additionally, using the trimmed sequences improves the speed of sequence matching algorithms. The smaller database greatly improves run times (up to 98%) and memory usage, not only of similarity searching (BLAST), but also of chimera checking (UCHIME) and of clustering the reads (UCLUST). TaxMan is available at http://www.ibi.vu.nl/programs/taxmanwww/.
    Description: University of Amsterdam under the research priority area ‘Oral Infections and Inflammation’ (to B.W.B.); National Science Foundation [NSF/BDI 0960626 to S.M.H.]; the European Union Seventh Framework Programme (FP7/ 2007-2013) under ANTIRESDEV grant agreement no 241446 (to E.Z.).
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  • 66
    Publication Date: 2022-05-25
    Description: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeochemistry 114 (2013): 11-23, doi:10.1007/s10533-012-9801-5.
    Description: Human actions have both intentionally and unintentionally altered the global economy of nitrogen (N), with both positive and negative consequences for human health and welfare, the environment and climate change. Here we examine long-term trends in reactive N (Nr) creation and efficiencies of Nr use within the continental US. We estimate that human actions in the US have increased Nr inputs by at least ~5 times compared to pre-industrial conditions. Whereas N2 fixation as a by-product of fossil fuel combustion accounted for ~1/4 of Nr inputs from the 1970s to 2000 (or ~7 Tg N year−1), this value has dropped substantially since then (to 〈5 Tg N year−1), owing to Clean Air Act amendments. As of 2007, national N use efficiency (NUE) of all combined N inputs was equal to ~40 %. This value increases to 55 % when considering intentional N inputs alone, with food, industrial goods, fuel and fiber production accounting for the largest Nr sinks, respectively. We estimate that 66 % of the N lost during the production of goods and services enters the air (as NO x , NH3, N2O and N2), with the remaining 34 % lost to various waterways. These Nr losses contribute to smog formation, acid rain, eutrophication, biodiversity declines and climate change. Hence we argue that an improved national NUE would: (i) benefit the US economy on the production side; (ii) reduce social damage costs; and (iii) help avoid some major climate change risks in the future.
    Description: This work resulted from a workshop supported by NSF Research Coordination Network Awards DEB-0443439 and DEB-1049744 and by the David and Lucille Packard Foundation.
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  • 67
    Publication Date: 2022-05-25
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Briefings in Bioinformatics 15 (2014): 783-787, doi:10.1093/bib/bbt010.
    Description: The extremely high error rates reported by Keegan et al. in ‘A platform-independent method for detecting errors in metagenomic sequencing data: DRISEE’ (PLoS Comput Biol 2012;8:e1002541) for many next-generation sequencing datasets prompted us to re-examine their results. Our analysis reveals that the presence of conserved artificial sequences, e.g. Illumina adapters, and other naturally occurring sequence motifs accounts for most of the reported errors. We conclude that DRISEE reports inflated levels of sequencing error, particularly for Illumina data. Tools offered for evaluating large datasets need scrupulous review before they are implemented.
    Description: National Institutes of Health [1UH2DK083993 to M.L.S.]; National Science Foundation [BDI- 096026 to S.M.H.].
    Keywords: Next-generation sequencing ; Sequencing error ; Adapter ligation ; PCR ; Quality score
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  • 68
    Publication Date: 2022-05-25
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Conservation Genetics Resources 5 (2013): 561-563, doi:10.1007/s12686-012-9852-x.
    Description: A total of one hundred microsatellites loci were selected from the draft genome of Stylophora pistillata and evaluated in previously characterized samples of Stylophora cf pistillata from the Red Sea. 17 loci were amplified successfully and tested in 24 individuals from samples belonging to a single population from the central region of the Red Sea. The number of alleles ranged from 3 to 15 alleles per locus, while observed heterozygosity ranged from 0.292 to 0.95. Six of these loci showed significant deviations from Hardy–Weinberg equilibrium (HWE) expectations, and 4/136 paired loci comparisons suggested linkage disequilibrium after Bonferroni corrections. After excluding loci with significant HWE deviation and evidence of null alleles, average genetic diversity over loci in the population studied (N = 24, Nloci = 11) was 0.701 ± 0.380. This indicates that these loci can be used effectively to evaluate genetic diversity and undertake population genetics studies in Stylophora sp. populations.
    Description: This research was funded by King Abdullah University of Science and Technology (KAUST), Saudi Arabia.
    Keywords: Stylophora ; Tetra and dinucleotide microsatellites ; Red Sea ; Coral
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  • 69
    Publication Date: 2022-05-25
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeochemistry 115 (2013): 299-315, doi:10.1007/s10533-013-9836-2.
    Description: A series of eight watersheds on the Pacific coast of Panama where conversion of mature lowland wet forest to pastures by artisanal burning provided watershed-scale experimental units with a wide range of forest cover (23, 29, 47, 56, 66, 73, 73, 91, and 92%). We used these watersheds as a landscape-scale experiment to assess effects of degree of deforestation on within-watershed retention and hydrological export of atmospheric inputs of nutrients. Retention was estimated by comparing rainfall nutrient concentrations (volume-weighted to allow for evapotranspiration) to concentrations in freshwater reaches of receiving streams. Retention of rain-derived nutrients in these Panama watersheds averaged 77, 85, 80, and 62% for nitrate, ammonium, dissolved organic N, and phosphate, respectively. Retention of rain-derived inorganic nitrogen, however, depended on watershed cover: retention of nitrate and ammonium in pasture-dominated watersheds was 95 and 98%, while fully forested watersheds retained 65 and 80% of atmospheric nitrate and ammonium inputs. Watershed forest cover did not affect retention of dissolved organic nitrogen and phosphate. Exports from more forested watersheds yielded DIN/P near 16, while pasture-dominated watersheds exported N/P near 2. The differences in magnitude of exports and ratios suggest that deforestation in these Panamanian forests results in exports that affect growth of plants and algae in the receiving stream and estuarine ecosystems. Watershed retention of dissolved inorganic nitrogen calculated from wet plus dry atmospheric deposition varied from 90% in pasture- to 65% in forest-dominated watersheds, respectively. Discharges of DIN to receiving waters from the watersheds therefore rose from 10% of atmospheric inputs for pasture-dominated watersheds, to about 35% of atmospheric inputs for fully forested watersheds. These results from watersheds with no agriculture or urbanization, but different conversion of forest to pasture by burning, show significant, deforestation-dependent retention within tropical watersheds, but also ecologically significant, and deforestation-dependent, exports that are biologically significant because of the paucity of nutrients in receiving tropical stream and coastal waters.
    Description: This work was funded by NSF Grant BIO- 0842413
    Keywords: Tropical watersheds ; Forests ; Pastures ; Nitrogen ; Phosphorus ; Evapotranspiration ; Groundwater
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  • 70
    Publication Date: 2022-05-25
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Reviews in Fish Biology and Fisheries 23 (2013): 317-364, doi:10.1007/s11160-012-9297-z.
    Description: A recent survey lists more than 100 papers utilizing the auditory evoked potential (AEP) recording technique for studying hearing in fishes. More than 95 % of these AEP-studies were published after Kenyon et al. introduced a non-invasive electrophysiological approach in 1998 allowing rapid evaluation of hearing and repeated testing of animals. First, our review compares AEP hearing thresholds to behaviorally gained thresholds. Second, baseline hearing abilities are described and compared in 111 fish species out of 51 families. Following this, studies investigating the functional significance of various accessory hearing structures (Weberian ossicles, swim bladder, otic bladders) by eliminating these morphological structures in various ways are dealt with. Furthermore, studies on the ontogenetic development of hearing are summarized. The AEP-technique was frequently used to study the effects of high sound/noise levels on hearing in particular by measuring the temporary threshold shifts after exposure to various noise types (white noise, pure tones and anthropogenic noises). In addition, the hearing thresholds were determined in the presence of noise (white, ambient, ship noise) in several studies, a phenomenon termed masking. Various ecological (e.g., temperature, cave dwelling), genetic (e.g., albinism), methodical (e.g., ototoxic drugs, threshold criteria, speaker choice) and behavioral (e.g., dominance, reproductive status) factors potentially influencing hearing were investigated. Finally, the technique was successfully utilized to study acoustic communication by comparing hearing curves with sound spectra either under quiet conditions or in the presence of noise, by analyzing the temporal resolution ability of the auditory system and the detection of temporal, spectral and amplitude characteristics of conspecific vocalizations.
    Description: Support from the Austrian Science Fund (FWF grant 22319 to F.L.).
    Keywords: AEP ; Hearing ; Sound pressure level ; Particle acceleration levels ; Thresholds ; Noise ; Ontogeny ; Communication
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  • 71
    Publication Date: 2022-05-25
    Description: © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Biodiversity 43 (2013): 237-241, doi:10.1007/s12526-013-0151-x.
    Description: Despite the ubiquitous role sponges play in reef ecosystem dynamics, little is known about population-level connectivity in these organisms. The general field of population genetics in sponges remains in its infancy. To date, microsatellite markers have only been developed for few sponge species and no sponge population genetics studies using microsatellites have been conducted in the Red Sea. Here, with the use of next-generation sequencing, we characterize 12 novel polymorphic loci for the common reef sponge, Stylissa carteri. The number of alleles per loci ranged between three and eight. Observed heterozygosity frequencies (Ho) ranged from 0.125 to 0.870, whereas expected (He) heterozygosity frequencies ranged from 0.119 to 0.812. Only one locus showed consistent deviations from Hardy-Weinberg equilibrium (HWE) in both populations and two loci consistently showed the possible presence of null alleles. No significant linkage disequilibrium was detected for any pairs of loci. These microsatellites will be of use for numerous ecological studies focused on this common and abundant sponge.
    Description: This work was funded by the King Abdullah University of Science and Technology.
    Keywords: Microsatellites ; Sponges ; Population genetics ; Connectivity ; Stylissa carteri
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  • 72
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    Oxford University Press
    In:  EPIC3Geophysical Journal International, Oxford University Press, 193(3), pp. 1399-1414, ISSN: 0956-540X
    Publication Date: 2019-07-16
    Description: The Boreas Basin is located in the Norwegian-Greenland Sea between Northeast Greenland and Svalbard. Towards the east, it is bounded by the ultraslow mid-ocean Knipovich Ridge. Here, we present a 340-km-long seismic refraction line acquired during the expedition ARK-XXIV/3 of research vessel Polarstern in 2009, using 18 ocean bottom seismometers. It crosses the central Boreas Basin from the Knipovich Ridge to the Northeast Greenland margin. Thus, the line provides the first reliable crustal structure information of this basin. In addition, the gravity data acquired parallel to the seismic refraction line are used to calculate a 2.5-D gravity model. The P-wave velocity model shows an unusual ∼3-km-thin oceanic crust with seismic velocities less than 6.3 km s−1, indicating the absence of a significant oceanic layer 3. Mantle velocities vary between 7.5 kms−1 in the uppermost mantle and 8.0 km s−1 at approximately 15 km depth. The low velocities within the upper mantle may be explained by 13 per cent serpentinisation, which is negligible at about 15 km depth. Furthermore, the S-wave velocity model shows low Vp/Vs ratios in the mantle, indicating a highly serpentinised mantle at shallow depths. The gravity model has crustal densities between 2.3 and 2.9 g cm−3, which also point towards the absence of a significant thick oceanic layer 3. The results of our seismic refraction line and other geophysical data indicate that the entire Boreas Basin opened at ultraslow spreading rates since at least ∼28 Ma. No evidence for an extinct spreading ridge in the centre of the Boreas Basin was found.
    Repository Name: EPIC Alfred Wegener Institut
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  • 73
    Publication Date: 2022-03-25
    Description: Polygon tundra characterizes large areas of arctic lowlands. The micro-relief pattern within polygons offers differentiated habitats for testate amoeba (testacean)communities. The objective of this study was to relate testacean species distribution within a polygon to the environmental setting. Therefore, testaceans from four cryosol pits dug at different locations within a low-centered polygon were studied in the context of pedological and pedochemical data, while ground temperature and ground moisture were measured over one summer season. The study site is located on the Berelekh River floodplain (Indigirka lowland, East Siberia). The environmental data sets reflect variations along the rim-to-center transect of the polygon and in different horizons of each pit. The testacean species distribution is mainly controlled by the soil moisture regime and pH. Most of the identified testaceans are cosmopolitans; eight species are described from an arctic environment for the first time. Differences in environmental conditions are controlled by the micro-relief of polygon tundra and must be considered in arctic lowland testacean research because they bias species composition and any further (paleo-)ecological interpretation.
    Repository Name: EPIC Alfred Wegener Institut
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  • 74
    Publication Date: 2022-05-26
    Description: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Biology 160 (2013): 1773-1787, doi:10.1007/s00227-012-2031-5.
    Description: Ocean acidification is increasingly recognized as a component of global change that could have a wide range of impacts on marine organisms, the ecosystems they live in, and the goods and services they provide humankind. Assessment of these potential socio-economic impacts requires integrated efforts between biologists, chemists, oceanographers, economists and social scientists. But because ocean acidification is a new research area, significant knowledge gaps are preventing economists from estimating its welfare impacts. For instance, economic data on the impact of ocean acidification on significant markets such as fisheries, aquaculture and tourism are very limited (if not non-existent), and non-market valuation studies on this topic are not yet available. Our paper summarizes the current understanding of future OA impacts and sets out what further information is required for economists to assess socio-economic impacts of ocean acidification. Our aim is to provide clear directions for multidisciplinary collaborative research.
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  • 75
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    Springer
    In:  EPIC3Earth System Science: Bridging the gaps between disciplines—A multi-disciplinary Helmholtz Graduate Research School, Berlin Heidelberg, Springer, 7 p., pp. 83-89, ISBN: 978-3-642-32235-8
    Publication Date: 2023-06-21
    Description: Geophysical data acquired along the Antarctic passive margins constrain the structure and geometry of the deformed continental crust. Crustal thickness estimates range between 7 and 50 km and the Antarctic continent–ocean transition zone (COTZ) extends up to 100–670 km towards the ocean. Continental deformation prior to rifting over a c. 100 million years long time span resulted in crustal stretching factors varying between 1.8 and 5.9. The time span of deformation was sufficiently large and the rifting velocity low enough to extend the margin by up to 300–400 km. Crustal thinning generates a significant subsidence and shallow water passages might already have developed during the rifting phase along the margin. Accounting for accurate continental margin deformation has also consequences for plate-tectonic reconstructions.
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  • 76
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    Springer
    In:  EPIC3Earth system science: bridging the gap between disciplines, Earth system science: bridging the gap between disciplines, Heidelberg, Springer, 7 p., pp. 97-103, ISBN: 978-3-642-32234-1
    Publication Date: 2023-06-21
    Description: Information about past environmental conditions is preserved in the elemental signature of biogenic marine carbonates. Thus, trace element to calcium ratios (Me/Ca) of biogenic calcium carbonates, such as bivalve shells, are often used to reconstruct past environmental conditions at the time of carbonate formation (Foster et al., 2008). In this study, we examine the suitability of the long-lived (〉 400 years) bivalve Arctica islandica as a high-resolution bioarchive by measuring Me/Ca ratios in the shell carbonate. Pb/Ca concentrations in A. islandica shells reflect anthropogenic gasoline lead consumption and further provide a centennial record of lead pollution for the collection site off the coast of Virginia, USA. With A. islandica shells from the North Sea we test the hypothesis that Ba/Ca and Mn/Ca ratios are indicators of the diatom abundance. Our results indicate that statistically both ratios correlate well with the diatom abundance, and yet, on a year-to-year base, there is no consistent reflection of diatom abundance patterns in the Ba/Ca and Mn/Ca annual profiles. These findings indicate that primary production affects Ba/Ca and Mn/Ca shell ratios, though we suggest that both elements are coupled to primary production through different processes and are affected by further, yet unknown processes.
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  • 77
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    Springer
    In:  EPIC3Earth System Science: Bridging the Gaps between Disciplines Perspectives from a Multi-disciplinary Helmholtz Research School, Heidelbert, Springer, 138 p., pp. 1-8, ISBN: 978-3-642-32234-1
    Publication Date: 2023-06-21
    Repository Name: EPIC Alfred Wegener Institut
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  • 78
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    Springer
    In:  EPIC3Earth System Science: Bridging the Gaps between Disciplines Perspectives from a Multi-disciplinary Helmholtz Research School, Heidelberg, Springer, 138 p., pp. 1-3, ISBN: 978-3-642-32234-1
    Publication Date: 2023-06-21
    Repository Name: EPIC Alfred Wegener Institut
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  • 79
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    Springer
    In:  EPIC3Earth System Modelling - Volume 6: ESM Data Archives in the Times of the Grid, Springer Briefs in Earth System Sciences, Berlin, Heidelberg, Springer, pp. 49-60, ISBN: 978-3-642-37243-8
    Publication Date: 2023-06-21
    Description: Grid technology can help scientists to overcome problems with the Data Deluge in climate research, as it facilitates large scale data sharing and reuse of data. Worldwide there are different initiatives to facilitate data handling for scientific work and to built up collaborational working environments with interinstitutional data access.
    Repository Name: EPIC Alfred Wegener Institut
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  • 80
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    Springer
    In:  EPIC3Earth System Science: Bridging the Gaps between Disciplines. Perspectives from a Multi-disciplinary Helmholtz Graduate Research School, Earth System Science: Bridging the Gaps between Disciplines. Perspectives from a Multi-disciplinary Helmholtz Graduate Research School, Heidleberg, Springer, 4 p., pp. 38-41, ISBN: 978-3-642-32234-1
    Publication Date: 2023-06-21
    Description: Growth of phytoplankton in the Southern Ocean (SO) is largely limited by insufficient concentrations of the micronutrient iron, so that despite the large macronutrient reservoir, the SO is considered a High Nutrient Low Chlorophyll region. Therefore, phytoplankton growth is enhanced where exogenous iron is introduced to the system, for example downstream from islands. These confined regions sustain very rich ecosystems and are hot spots for atmospheric carbon dioxide drawdown. In this study, a combination of satellite derived measurements and model simulations are used to investigate the biological and physical environmental disturbances of the island of South Georgia (37°W, 54°S), which is located in the southwestern part of the Atlantic sector of the SO. We show not only that the island shelf is an important source of dissolved iron to the system, but also that the characteristic surface circulation patterns found downstream of the island play an important role in maintaining the shape and distribution of the developing phytoplankton bloom.
    Repository Name: EPIC Alfred Wegener Institut
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  • 81
    Publication Date: 2020-10-26
    Description: One of the main objectives of the ITACA (ITalian ACcelerometric Archive) strong motion database, promoted by the Italian Department of Civil Protection, was to improve the characterization of the recording sites from a geological and geophysical point of view and to provide their seismic classification according to the seismic norms pertinent to Italy, namely the Eurocode 8 and the National Technical Norms for Constructions. A standard format to summarize the available information for the recording stations was first produced, in terms of a technical report dynamically linked to the database, i.e., some of the relevant information is automatically updated when the corresponding fields of the database are modified. Then, an important activity of collection, qualification and synthesis of available data was carried out, especially for stations that recorded the strongest earthquakes in Italy in the last 40 years, and for which a relevant number of studies have been published. In spite of this activity, among the more than 700 strong motion stations present in the ITACA database, only a limited number of them could be characterized by quantitative information on subsurface soil properties. For this reason, a dual seismic site classification criterion was implemented, either based on the standard Vs,30 scheme, or, in the absence of such information, based on an expert opinion supported by shallow geology maps, mostly at 1:100,000 scale, and when available on the H/V ratios calculated on recordings. Owing to the relevance in the Italian geographic and morphological context, a special care was also given to the topographic classification of stations, based on suitable criteria developed within a GIS environment.
    Description: Published
    Description: 1779-1796
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: open
    Keywords: ITACA database ; Strong motion station ; General characterization ; Site classification ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 05. General::05.02. Data dissemination::05.02.02. Seismological data ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 82
    Publication Date: 2020-11-26
    Description: So far, the role of appendicularians in the biogeochemical cycling of organic matter has been largely overlooked. Appendicularians represent only a fraction of total mesozooplankton biomass, however these ubiquitous zooplankters have very high filtration and growth rates compared to copepods, and produce numerous fecal pellets and filtering houses contributing to export production by aggregating small marine particles. To study their quantitative impact on biogeochemical flux, we have included this group in the biogeochemical flux model, using a recently developed ecophysiological model. One-dimensional annual simulations of the pelagic ecosystem including appendicularians were conducted with realistic surface forcing for the year 2000, using data from the DyFAMed open ocean station. The appendicularian grazing impact was generally low, but appendicularians increased detritus production by 8% and export production by 55% compared to a simulation without appendicularians. Therefore, current biogeochemical models lacking appendicularians probably under, or misestimate the detritus and export production by omitting the pathway from small-sized plankton to fast sinking detritus. Detritus production and export rates are 60% lower than the estimates from mesotrophic sites, showing that appendicularians’ role is lower but still significant in oligotrophic environments. The simulated annual export at 200 m exceeds sediment trap values by 44%, suggesting an intense degradation during the sinking of appendicularian detritus, supported by observations made at other sites. Thus, degradation and grazing of appendicularian detritus need better quantification if we are to accurately assess the role of appendicularia in export flux.
    Description: EU-FP6 project SESAME GOCE-036949
    Description: Published
    Description: 855-872
    Description: 3.7. Dinamica del clima e dell'oceano
    Description: JCR Journal
    Description: reserved
    Keywords: BFM ; zooplankton ; 03. Hydrosphere::03.01. General::03.01.01. Analytical and numerical modeling ; 03. Hydrosphere::03.01. General::03.01.07. Physical and biogeochemical interactions ; 03. Hydrosphere::03.04. Chemical and biological::03.04.01. Biogeochemical cycles ; 03. Hydrosphere::03.04. Chemical and biological::03.04.04. Ecosystems
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 83
    Publication Date: 2017-04-04
    Description: Previous works based mainly on strong-motion recordings of large Japanese earthquakes showed that site amplification and soil fundamental frequency could vary over long and short time scales. These phenomena were attributed to non-linear soil behaviour: the starting fundamental frequency and amplification were both instantaneously decreasing and then recovering for a time varying from few seconds to several months. The recent April 6, 2009 earthquake (M W 6.3), occurred in the L’Aquila district (central Italy), gave us the possibility to test hypotheses on time variation of amplification function and soil fundamental frequency, thanks to the recordings provided by a pre-existing strong-motion array and by a large number of temporary stations. We investigated the intra- and inter-event soil frequency variations through different spectral analyses, including time-frequency spectral ratios and S-Transform (Stockwell et al. in IEEE Trans Signal Process 44:998–1001, 1996). Finally, analyses on noise recordings were performed, in order to study the soil behaviour in linear conditions. The results provided puzzling evidences. Concerning the long time scale, little variation was observed at the permanent stations of the Aterno Valley array. As for the short time-scale variation, the evidence was often contrasting, with some station showing a time-varying behavior, while others did not change their frequency with respect to the one evaluated from noise measurements. Even when a time-varying fundamental frequency was observed, it was difficult to attribute it to a classical, softening non-linear behaviour. Even for the strongest recorded shocks, with peak ground acceleration reaching 0.7 g, variations in frequency and amplitude seems not relevant from building design standpoint. The only exception seems to be the site named AQV, where the analyses evidence a fundamental frequency of the soil shifting from 3 Hz to about 1.5 Hz during the mainshock.
    Description: Published
    Description: 869-892
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: open
    Keywords: Strong motion ; Subsoil non-linearity ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 84
    Publication Date: 2017-04-04
    Description: Crystal-rich lithic clasts occurring in volcanic deposits are key tools to understand processes of storage, cooling, and fractionation of magmas in pre-eruptive volcanic systems. These clasts, indeed, represent snapshots of the magma-chamber/host-rock interface before eruptions and provide information on crystallization, differentiation, and degrees of interaction between magma and wall-rocks. In this study, with the aim to shed light on magma-carbonate interaction and CO2 emission in volcanic areas, we focused on the petrology of cumulate and skarn rocks by using as case study a suite of mafic and calcite-bearing lithic clasts from the Colli Albani Volcanic District. By means of phase relations, bulk rock chemistry, phase compositions, and stable isotope data we have recognized different types of cumulates and skarns. Cumulates containing either clinopyroxene±olivine associated with Cr-bearing spinel or glass+phlogopite have been divided in primitive and differentiated, respectively. Primitive cumulates originate at the interface between a relatively primitive magma and carbonate-bearing rocks and show evidences of olivine instability (i.e. heteradcumulate texture) due to carbonate assimilation. Differentiated cumulates, characterized by Ca-rich olivines, phlogopite, and glass containing calcite, form from a differentiated magma in a system open to CaO-contamination. Skarns has been divided in exoskarns, characterized by xenomorphic texture and abundant calcite, and endoskarns, characterized by hypidiomorphic texture, Ca-Tschermak-rich mineral phases, and interstitial glass. Exoskarns formed by means of solid state reactions in a dolostone protolith whereas endoskarns crystallized at subliquidus temperature from a silicate melt that experienced exoskarns assimilation. Our study evidences that magma-carbonate interaction can not be considered a one step process exhausting just after the formation of skarn shells. Magma and carbonate rocks, when in contact, continuously interact leading to the formation of exoskarns, endoskarns, cumulates (primitive and differentiated ones), and differentiated melts. Finally, by means of oxygen and carbon isotope compositions of calcite in equilibrium with skarns, we demonstrate that carbonate assimilation represents a source of massive CO2 degassing mechanism due to the consumption of calcite and removing of CO2 during the decarbonation process.
    Description: Sapienza Universita' di Roma INGV-DPC [Project V 3.1, Colli Albani].
    Description: Published
    Description: 2307-2332
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: JCR Journal
    Description: reserved
    Keywords: magma/carbonate interaction ; CO2 degassing ; c umulate and skarn ; Colli Albani ; 04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 85
    Publication Date: 2017-04-04
    Description: We exploit S-wave spectral amplitudes from 112 aftershocks (3.0 ≤ ML ≤ 5.3) of the L’Aquila 2009 seismic sequence recorded at 23 temporary stations in the epicentral area to estimate the source parameters of these events, the seismic attenuation characteristics and the site amplification effects at the recording sites. The spectral attenuation curves exhibit a very fast decay in the first few kilometers that could be attributed to the large attenuation of waves traveling trough the highly heterogeneous and fractured crust in the fault zone of the L’Aquila mainshock. The S-waves total attenuation in the first 30 km can be parameterized by a quality factor QS(f) = 23f^0.58 obtained by fixing the geometrical spreading to 1/R. The source spectra can be satisfactorily modeled using the omega-square model that provides stress drops between 0.3 and 60 MPa with a mean value of 3.3±2.8 MPa. The site responses show a large variability over the study area and significant amplification peaks are visible in the frequency range from 1 to more than 10 Hz. Finally, the vertical component of the motion is amplified at a number of sites where, as a consequence, the horizontal-to-vertical spectral ratios (HVSR) method fails in detecting the amplitude levels and in few cases the resonance frequencies.
    Description: Published
    Description: 717-739
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: reserved
    Keywords: Generalized Inversion Technique ; 2009 L'Aquila earthquake ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 86
    facet.materialart.
    Unknown
    Springer
    Publication Date: 2017-04-04
    Description: Previous research works proved the existence of a synchronization between speech and holds in adults and in 9 year old children with a rich linguistic vocabulary and advanced language skills. When and how does this synchrony develop during child language acquisition? Could it be observed also in children younger than 9? The present work aims to answer the above questions reporting on the analysis of narrations produced by three different age groups of Italian children (9, 5 and 3 year olds). Measurements are provided on the amount of synchronization between speech pauses and holds in the three different groups, as a function of the duration of the narrations. The results show that, as far as the reported data concerns, in children, as in adults, holds and speech pauses are to a certain extent synchronized and play similar functions, suggesting that they may be considered as a multi-determined phenomenon exploited by the speaker under the guidance of a unified planning process to satisfy a communicative intention. In addition, considering the role that speech pauses play in communication, we speculate on the possibility that holds may serve to similar purposes supporting the hypothesis that gestures as speech are an expressive resource that can take on different functions depending on the communicative demand. While speech pauses are likely to play the role of signalling mental activation processes aimed at replacing the “old spoken content” of the communicative plan with a new one, holds may signal mental activation processes aimed at replacing the “old visible bodily action” with new ones reflecting the representational and/or propositional contribution of gestures to the new communicative plan.
    Description: Published
    Description: 252-272
    Description: 5.9. Formazione e informazione
    Description: restricted
    Keywords: Speech pauses, holds, synchrony, child narrations ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 87
    Publication Date: 2017-04-04
    Description: The selection of specific elastic response spectra according to soil categories is the easiest way to account for site effects in engineering projects and general-purpose hazard maps. Most of the international seismic codes make use of the average shear wave velocity of the upper 30 m (Vs,30) to discriminate soil categories, although some doubts arose about the capability of Vs,30 to predict actual soil amplification. In this work we propose two soil classifications in which the soil fundamental frequency (f0) becomes either an alternative or a complement to Vs,30. The performance of the derived categorizations is achieved through the estimation of the standard deviation associated to ground motion prediction equations of acceleration response spectra, considering recordings extracted from the Italian strong motion data base. The results indicate that there is a significant reduction of the standard deviation when the classification is based on the couple of variables Vs,30–f0, although a classification based of the single f0 also leads to satisfactory results, comparable with those obtained assuming a classification scheme based on Vs,30.
    Description: Published
    Description: 1877-1898
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: reserved
    Keywords: site effects ; soil classification ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 88
    facet.materialart.
    Unknown
    Springer
    Publication Date: 2017-04-04
    Description: n/a
    Description: Published
    Description: 125-127
    Description: 3.3. Geodinamica e struttura dell'interno della Terra
    Description: restricted
    Keywords: Core-mantle boundary topography ; Seismology ; 04. Solid Earth::04.01. Earth Interior::04.01.03. Mantle and Core dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 89
    Publication Date: 2020-02-24
    Description: The S1 pecial Issue of the Bulletin of Earthquake Engineering devoted to the new 2 Italian strong motion database ITACA (ITalian ACelerometric Archive) is introduced in this 3 foreword. An overview of the papers published in this issue is presented, providing an idea of 4 the number of problems encountered in the compilation of a database as rich of information 5 as ITACA, of the solutions adopted and of the possible research and practical applications. 6 Most of the contents, though specifically addressed to ITACA and to its accelerograms, can 7 be usefully thought of as an exemplification of approaches and methods that can be used for, 8 and extended to, similar databases in other countries
    Description: Published
    Description: 1717-1721
    Description: 5.2. TTC - Banche dati di sismologia strumentale
    Description: JCR Journal
    Description: reserved
    Keywords: Strong motion database ; ITACA ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 90
    Publication Date: 2017-04-04
    Description: We have studied two velocity-depth models with the aim of outlining the behavior of a velocity reversal in the top layer, which is associated with the stiff Brecce de L’Aquila unit (BrA). In this setting, the SMTH model is topped by a layer with about 2:1 impedance contrast with the underlying layer while the NORV model has no velocity reversal. We have simulated the propagation of SH and P-SV wavefields in the range 0–10 Hz for incidence 0◦ –90◦ . Earthquake spectral ratios of the horizontal and vertical components at six sites in L’Aquila downtown are compared to corresponding syn- thetics spectral ratios. The vertical component of P-SV synthetics enables us to investigate a remarkable amplification effect seen in the vertical component of the recorded strong motion. Sites AQ04 and AQ05 are best matched by synthetics from the NORV model while FAQ5 and AQ06 have a better match with synthetics spectral ratios from the SMTH model. All simulations show this behavior systematically, with horizontal and near-horizontal incident waves predicting the overall pattern of matches more clearly than vertical and near-vertical incidence. The model inferences are in agreement with new geological data reporting lateral passages in the top layer from the stiff BrA to softer sediments. Matches are good in terms of frequency of the first amplification peak and of spectral amplitude: the horizontal compo-nents have spectral ratio peaks predominantly at 0.5 Hz in the simulations and at 0.7 Hz in the data, both with amplitudes of 4, while the vertical component spectral ratios reach values of 6 at frequencies of about 1 Hz in both data and simulations. The vertical component spectral ratios are very well matched using Rayleigh waves with incidence at 90◦ . The NORV model without the velocity reversal predicts spectral ratio peaks for the horizontal components at frequencies up to 6 Hz. The reversal of velocity acts as a low-pass frequency filter on the horizontal components reducing the amplification effect of the sediment filled valley.
    Description: Published
    Description: 761-781
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: reserved
    Keywords: site effect, 2D synthetic seismograms, spectral ratios, reversal of velocity, L'Aquila ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 91
    Publication Date: 2017-04-04
    Description: In this work, we investigate the site amplification effects observed in the Norcia plain, Central Italy. Data from 30 selected local earthquakes (2 ≤ Ml ≤ 4.1) recorded by a temporary seismic network composed by 15 stations, are analyzed to determine the spa- tial variability of site effects. Both the Horizontal-to-Vertical spectral ratio and the Standard Spectral Ratio techniques are applied to estimate the site amplification effects. The results show that most of the sites in the valley are affected by strong amplifications (up to a factor of 20) in the frequency range 0.5–5 Hz. The value of the fundamental frequency of resonance is strictly dependent on the location within the basin and on the sediment thickness. Strong amplifications also affect the vertical components. The time-frequency analysis performed on a station located inside the basin shows the presence of a large spectral amplitudes after the S-wave phase, not observed on a station located on the bedrock, suggesting the pres- ence of locally generated wave trains. Then, in agreement with earlier observations for other alluvial basins in Central Italy, 2D–3D effects play an important role in determining the site amplification effects in Norcia.
    Description: Published
    Description: 1941-1959
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: reserved
    Keywords: site effects ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 92
    Publication Date: 2017-04-04
    Description: We performed geodetic strain rate analyses in southern Italy, using new GPS velocities. Two-dimensional strain and rotation rate fields were estimated and results show that most of the shortening is distributed in the northern Sicily offshore. Extension becomes more evident and comparable with shortening on the eastern side of the same margin, and greater in the eastern Sicily offshore. Principal shortening and extension rate axes are consistent with longterm geological features: seismic reflection profiles show both active compressive and extensional faults affecting Pleistocene strata. We show evidence for contemporaneous extension and transtension in the Cefalu` Basin. Combining geodetic data and geological features point to the coexistence of independent geodynamic processes, i.e., the active E–W backarc spreading in the hangingwall of the Apennines subduction zone and shortening along the southern margin of the Tyrrhenian backarc basin operated by the NNW-motion of Africa relative to Eurasia.
    Description: Published
    Description: 1915-1924
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: restricted
    Keywords: Southern Tyrrhenian Sea ; GPS-derived strain rate ; Seismic reflection profiles ; Coexisting tectonics ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 93
    Publication Date: 2017-04-04
    Description: The Italian Strong Motion Database, ITACA, was developed within projects 2 S6 and S4, funded in the framework of the agreements between the Italian Department of 3 Civil Protection (Dipartimento della Protezione Civile, DPC) and the Istituto Nazionale di 4 Geofisica e Vulcanologia (INGV), starting from 2005. The alpha version of the database 5 was released in 2007 and subsequently upgraded to version 1.0 after: (i) including the most 6 recent strongmotion data (from2005 to 2007) recorded in Italy, in addition to the 2008 Parma 7 earthquake, M 5.4, and the M 4.0, 2009 Abruzzo seismic events; (ii) processing the raw 8 strong motion data using an updated procedure; (iii) increasing the number of stations with a 9 measured shear wave velocity profile; (iv) improving the utilities to retrieve time series and 10 ground motion parameters; (v) implementing a tool for selecting time series in agreement 11 with design-response spectra; (vi) compiling detailed station reports containing miscella12 neous information such as photo, maps and site parameters; (vii) developing procedures for 13 the automatic generation of station reports and for the updating of the header files. After such 14 improvements, ITACA 1.0 was published at the web site http://itaca.mi.ingv.it, in 2010. It 15 presently contains 3,955 three-component waveforms, comprising the most complete cata16 logue of the Italian accelerometric records in the period 1972–2007 (3,562 records) and the 17 strongest events in the period 2008–2009. Records were mainly acquired by DPC through its 18 Accelerometric National Network (RAN) and, in few cases, by local networks and temporary 19 stations or networks. This paper introduces the published version of the Italian StrongMotion 20 database (ITACA version 1.0) together with main improvements and new functionalities.
    Description: Published
    Description: 1723-1739
    Description: 5.2. TTC - Banche dati di sismologia strumentale
    Description: JCR Journal
    Description: open
    Keywords: italian strong motion data ; web-portal ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 94
    Publication Date: 2017-04-04
    Description: Using a lava flow emplacement model and a satellite-based land cover classification, we produce a map to allow assessment of the type and quantity of natural, agricultural and urban land cover at risk from lava flow invasion. The first step is to produce lava effusion rate contours, i.e., lines linking distances down a volcano’s flank that a lava flow will likely extend if fed at a given effusion rate from a predetermined vent zone. This involves first identifying a vent mask and then running a downhill flow path model from the edge of every pixel around the vent mask perimeter to the edge of the DEM. To do this, we run a stochastic model whereby the flow path is projected 1,000 times from every pixel around the vent mask perimeter with random noise being added to the DEM with each run so that a slightly different flow path is generated with each run. The FLOWGO lava flow model is then run down each path, at a series of effusion rates, to determine likely run-out distance for channel-fed flow extending down each path. These results are used to plot effusion rate contours. Finally, effusion rate contours are projected onto a land classification map (produced from an ASTER image of Etna) to assess the type and amount of each land cover class falling within each contour. The resulting maps are designed to provide a quick look-up capability to assess the type of land at risk from lava extending from any location at a range of likely effusion rates. For our first (2,000 m) vent zone case used for Etna, we find a total of area of ~680 km2 is at risk from flows fed at 40 m3 s−1, of which ~6 km2 is urban, ~150 km2 is agriculture and ~270 km2 is grass/woodland. The model can also be run for specific cases, where we find that Etna’s 1669 vent location, if active today, would likely inundate almost 11 km2 of urban land, as well as 15.6 km2 of agricultural land, including 9.5 km2 of olive groves and 5.2 km2 of vineyards and fruit/nut orchards.
    Description: Published
    Description: 1001-1027
    Description: 3.6. Fisica del vulcanismo
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: reserved
    Keywords: Lava flow ; Risk ; FLOWGO ; ASTER image ; Land classification ; Mt. Etna ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 95
    Publication Date: 2017-04-04
    Description: This paper describes the analyses of the single-station ambient-vibration measurements performed on the Italian accelerometric network to detect site resonance phenomena potentially affecting earthquake recordings. The use of low cost, high quality microtremor measurement can be helpful to discriminate among soil classes, since several classification schemes based on resonance frequencies were proposed in the last decades. Operatively, in the framework of the Italian Strong Motion Database project (DPC-INGV 2007–2009 S4; http://esse4.mi.ingv.it), soil resonance frequencies have been evaluated from more than 200 ambient vibration measurements in correspondence of accelerometric stations included in ITACA (http://itaca.mi.ingv.it/ItacaNet/). The noise recordings have been analyzed using the same numerical protocol in order to standardize the results. Particular attention has been paid to evaluate the quality of measurements and to develop an on-purpose mathematical tool to automatically estimate the peaks in the horizontal-to-vertical spectral ratio (HVSR) curve. The reliability of the resonance frequencies from HVSR has been tested by comparing estimates provided by independent methods (modeling or earthquake recordings). The test confirmed the reliability of the microtremor HVSR for assessing the resonance frequencies of the examined sites.
    Description: Published
    Description: 1821-1838
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: JCR Journal
    Description: open
    Keywords: Ambient vibration measurements ; Strong motion database ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 96
    Publication Date: 2017-04-03
    Description: Among the eruptive styles, the Strombolian activity is one of the more easy to study because of its repetitive behavior. For this reason large amount of data can be comfortably collected. Strombolian volcanoes are like natural laborato- ries repeating the same experiment (individual explosions) many times each day. The development of quantitative models of eruptive dynamics is driven by the comparison of experimental ob- servations and synthetic data obtained through mathemat- ical, numerical or analogue modeling. Since Strombolian activity offers a profuse amount of interesting seismic signals, during the last decades there has been growing attention on seismological techniques aimed at retrieving the conduit geometry and the eruption dynamics from the seismological recordings. One of these techniques, the source function inversion, is able to re- trieve a summary of the forces acting on the volcanic con- duit during the VLP event generation [5]. The comparison of observed source functions with synthetic ones, obtained through numerical modeling, allow us to put constraints on the proposed models. Quantitative models, able to fit seismological observa- tions, are a powerful tool for interpreting seismic record- ings and therefor the seismological monitoring of active volcanoes.
    Description: Published
    Description: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Description: restricted
    Keywords: Strombolian activity ; Slug flow ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
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  • 97
    Publication Date: 2017-04-04
    Description: Seismic activity, ground deformation, and soil and fumarole temperatures acquired during 2004–2007 at Vulcano (Aeolian Islands) are analysed and the time relations among the different time series are discussed. Changes in temperature of fumarolic gases took place during four ‘‘anomalous’’ periods (November 2004–March 2005; October 2005–February 2006; August–October 2006; July–December 2007) at the same time as an increasing number of volcano-seismic events. In particular, the temperatures at high temperature vents and at steam heated soil ranged in time from 180 to 440 C and from 20 to 90 C, respectively. The maximum daily number of volcano-seismic events was 57, reached during the second anomalous period. This seismicity, characterised by focal depth generally lower than 1 km below sea level (b.s.l.) and composed of different kinds of events associated to both resonance and shear failure processes, is related to the shallow dynamics of the hydrothermal system. During the analysed period, very few volcano-tectonic earthquakes took place and tilt recordings showed no sharp or important changes. In light of such observations, the increases in both temperature and volcano-seismic events number were associated to increases in the release of gas from a deep and stable magma body, without magma intrusions within the shallow hydrothermal system. Indeed, a greater release of gas from depth leads to increased fluid circulation, that can promote increases in volcano-seismic events number by both fracturing processes and resonance and vibration in cracks and conduits. The different trends observed in the measured geochemical and geophysical series during the anomalous periods can be due to either time changes in the medium permeability or a changing speed of gas release from a deep magma body. Finally, all the observed variations, together with the changing temporal distribution of the different seismic event kinds, suggest that the hydrothermal system at Vulcano can be considered unsteady and dynamic.
    Description: Published
    Description: 167–182
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: JCR Journal
    Description: reserved
    Keywords: Volcano seismolog ; soil and fumarole temperatures ; tilt data ; hydrothermal system ; Vulcano Island ; volcanic unrest ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 98
    Publication Date: 2018-03-21
    Description: Among surface waters, lakes in volcanic areas display the greatest range in pH values (from negative values up to about 12). The present chapter will be a short review of the main features of alkaline lakes, which belong to the high-pH part of this range. They are characterised by saline or hypersaline waters, pH values higher than 9 and high Na+, HCO3- and CO32- and low Ca2+ concentrations. Alkaline lakes are found in quiescent or recently extinct volcanic areas where neither water vapour nor acidic magmatic gases can reach surface waters. Their occurrence depends on peculiar climatic and geologic conditions that allow evaporative concentration of the water (potentially, evaporation much higher than water inputs and endorheic basins) and on geochemical factors that favour a chemical evolution towards an alkaline environment (composition of the dilute input waters characterised by a ratio between total dissolved inorganic carbon and earth-alkaline elements much higher than 1). Such initial composition, due to evaporative concentration, after the deposition of earth-alkaline carbonate minerals, will lead to the above-mentioned typical composition. Alkaline lakes also host microbial communities sometimes characterised by extremely high productivity. These microbial communities are scientifically remarkable because they comprise some interesting extremophiles, which can grow not only at very high pH and salinity conditions but also in the presence of elevated concentrations of toxic elements (e.g. As, Se, Te).
    Description: Submitted
    Description: 4.4. Scenari e mitigazione del rischio ambientale
    Description: reserved
    Keywords: volcanic lake, soda lake, alkaline lake ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 99
    Publication Date: 2019-12-09
    Description: . In this work we analysed the time series of daily solutions of 4 Italian GPS permanent stations with the aim of investigating the presence of temporal correlations and their impact on the estimation of weekly solution and velocity field precisions. We found that precisions are remarkably lower when temporal correlations are considered; in particular, the mean horizontal precisions of weekly solutions are up to 5 times lower and the horizontal velocity precisions are about 1.5-2 times lower. This topic has 2 relevant applications: the assessment of the quality of a reference system maintenance by GPS permanent stations and the coordinate differences significance test for geodynamical applications.
    Description: Published
    Description: 1.9. Rete GPS nazionale
    Description: N/A or not JCR
    Description: restricted
    Keywords: GPS permanent network,temporal correlations, autocovariance functions ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.03. Geodesy::04.03.08. Theory and Models
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 100
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
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