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Author Carlo Cauzzi, Susana Custódio, Christos P. Evangelidis, Giovanni Lanzano, Lucia Luzi, Lars Ottemöller, Helle Pedersen, Reinoud Sleeman
Title Preface to the Focus Section on European Seismic Networks and Associated Services and Products Type Journal
Year 2021 Publication Seismological Research Letters Abbreviated Journal
Volume 92 Issue 3 Pages 1483-1490
Keywords
Abstract Most of the articles of this focus section serve as good examples in the open science domain, in which data are expected to be “findable, accessible, interoperable, and reusable” (Wilkinson et al., 2016). In many contributions, emphasis is placed on quality: as automated access to seismological archives via standardized web services emerges as the preferred user strategy, ensuring the high quality of data and metadata becomes more and more important (e.g., Büyükakpınar et al., 2021; Cambaz et al., 2021; Carrilho et al., 2021; Evangelidis et al., 2021; Mader and Ritter, 2021; Ottemöller et al., 2021; Péquegnat et al., 2021; Stammler et al., 2021; Strollo et al., 2021). Quality is especially important at a time when very large datasets are increasingly being processed routinely and “blindly” in machine‐learning approaches. The vast majority of seismological data centers already manage multisensor archives (seismometers, accelerometers, infrasound, amphibian seismological instruments, high‐rate global navigation satellite systems, etc.), and the inclusion of new types of data (e.g., rotational sensors, low‐cost instrumentation, and synthetic waveforms) in seismological archives poses new challenges and prompts for new technical solutions and standards for data archiving, metadata preparation, quality checks, data dissemination, and processing. A particular challenge over the next few years (Quinteros, Carter, et al., 2021) is the upcoming massive growth of data volume, due in particular to new instruments (large‐N experiments and distributed acoustic sensing systems) but also to increased volumes of traditional seismic data. It is expected that multisensor experiments will progressively dominate the technical and scientific discussion in geosciences in the coming decade, spurred by the societal need to develop multidisciplinary, multihazard science and research products. Joining forces and competences is therefore key to addressing future challenges: the EarthScope Consortium was recently established in the United States, and the European Plate Observing System (EPOS) was created as the framework to integrate all geoscience services in the greater European region. ORFEUS and its seismic network community strongly support the development and consolidation of EPOS by participating in the activities of its thematic core service for seismology.
Programme 133
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN (up) 0895-0695 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8429
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Author Martin Tournier, Pauline Goulet, Nadège Fonvieille, David Nerini, Mark Johnson, Christophe Guinet
Title A novel animal-borne miniature echosounder to observe the distribution and migration patterns of intermediate trophic levels in the Southern Ocean Type Journal
Year 2021 Publication Journal of Marine Systems Abbreviated Journal
Volume 223 Issue Pages 103608
Keywords Biologging Diel vertical migration Functional data analysis Marine acoustics Micronekton Sonar tag
Abstract Despite expanding in-situ observations of marine ecosystems by new-generation sensors, information about intermediate trophic levels remains sparse. Indeed, mid-trophic levels, while encompassing a broad range of zooplankton and micronekton organisms that represent a key component of marine ecosystems and sustain large and diverse communities of marine predators, are challenging to sample and identify. In this study, we examined whether an animal-borne miniature active echosounder can provide information on the distribution and movements of mid-trophic level organisms. If so, such a sonar tag, harnessing the persistent diving behaviour of far-ranging marine mammals, could greatly increase the density of data on this under-studied biome. High-frequency (1.5 MHz) sonar tags were deployed simultaneously with oceanographic tags on two southern elephant seals (Mirounga leonina), at the Kerguelen Islands and Valdés Peninsula (Argentina), and recorded acoustic backscatter while the seals foraged respectively in the Indian and the Atlantic sectors of the Southern Ocean. The backscatter varied widely over time and space, and the seals attempted to capture only a small fraction of the insonified targets. Diel vertical migration patterns were clearly identifiable in the data, reinforcing our confidence in the ability of the sonar tags to detect living mid-trophic organisms along with possibly sinking biological detritus. Moreover, CTD tags attached to the same animals indicated how the abundance, size distribution, and diel migration behaviour of acoustic targets varied with water bodies. These preliminary results demonstrate the potential for animal-borne sonars to provide detailed in-situ information. Further validation effort will make it a valuable tool to refine the estimation of carbon export fluxes as well as for assessing the variation of mid-trophic level biomass according to oceanographic domains and seasons.
Programme 1201
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ISSN (up) 0924-7963 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8260
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Author N. Aubone, M. Saraceno, M. L. Torres Alberto, J. Campagna, L. Le Ster, B. Picard, M. Hindell, C. Campagna, C. R. Guinet
Title Physical changes recorded by a deep diving seal on the Patagonian slope drive large ecological changes Type Journal
Year 2021 Publication Journal of Marine Systems Abbreviated Journal
Volume 223 Issue Pages 103612
Keywords Elephant seals Malvinas current Patagonian shelf slope Southwestern Atlantic Ocean
Abstract The Patagonian slope is the region where Subantarctic waters and bathymetry give raise to physical and ecological processes that support a rich biodiversity and a large-scale industrial fisheries. Unique among the species that depend on this region is the deep diving southern elephant seal, Mirounga leonina. We report here on changes in the foraging behavior of a female seal explained by the combined effect of a cold and high salinity water mass and a decrease in surface chlorophyll-a concentration. Behavioral and oceanographic data from about 5000 profiles of temperature, conductivity, pressure, light and prey encounters were collected within an area ranging 59.5–61°W and 46–47.5°S, at depths of 300–700 m, on the Patagonian slope, during November–December 2018. A decrease in temperature (0.15 °C) and an increase in salinity (0.03) was found below the mixed layer, during December. Light data revealed a significant increase of irradiance in December (almost reaching the ocean bottom) associated with a decrease of chlorophyll-a in the upper levels. Concomitantly, the seal had a different diving behavior in December, foraging near the surface at night and close to the bottom during daylight hours. Also, the seal doubled the prey capture attempts in December compared to November. This study reveals the importance of ocean physical properties on seal's diving and foraging behavior, and how this changes, although small, can impact on seals diet and body composition during their post-breeding trips.
Programme 1201
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ISSN (up) 0924-7963 ISBN Medium
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Notes Approved yes
Call Number Serial 8771
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Author Joanna Charton, Vincent Jomelli, Irene Schimmelpfennig, Deborah Verfaillie, Vincent Favier, Fatima Mokadem, Adrien Gilbert, Fanny Brun, Georges Aumaître, Didier L. Bourlès, Karim Keddadouche
Title A debris-covered glacier at Kerguelen (49°S, 69°E) over the past 15 000 years Type Journal
Year 2021 Publication Antarctic Science Abbreviated Journal
Volume 33 Issue 1 Pages 103-115
Keywords Antarctic Cold Reversal glacier fluctuations Holocene in situ cosmogenic chlorine-36 dating palaeoclimate sub-Antarctic
Abstract Debris-covered glaciers constitute a large part of the world's cryosphere. However, little is known about their long-term response to multi-millennial climate variability, in particular in the Southern Hemisphere. Here, we provide first insights into the response of a debris-covered glacier to multi-millennial climate variability in the sub-Antarctic Kerguelen Archipelago, which can be compared to that of recently investigated debris-free glaciers. We focus on the Gentil Glacier and present 13 new 36Cl cosmic-ray exposure ages from moraine boulders. The Gentil Glacier experienced at least two glacial advances: the first one during the Late Glacial (19.0–11.6 ka) at ~14.3 ka and the second one during the Late Holocene at ~2.6 ka. Both debris-covered and debris-free glaciers advanced broadly synchronously during the Late Glacial, most probably during the Antarctic Cold Reversal event (14.5–12.9 ka). This suggests that both glacier types at Kerguelen were sensitive to abrupt temperature changes recorded in Antarctic ice cores, associated with increased moisture. However, during the Late Holocene, the advance at ~2.6 ka was not observed in other glaciers and seems to be an original feature of the debris-covered Gentil Glacier, related to either distinct dynamics or to distinct sensitivity to precipitation changes.
Programme 1048
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Series Editor Series Title Abbreviated Series Title
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ISSN (up) 0954-1020, 1365-2079 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8186
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Author Deborah Verfaillie, Joanna Charton, Irene Schimmelpfennig, Zoe Stroebele, Vincent Jomelli, François Bétard, Vincent Favier, Julien Cavero, Etienne Berthier, Hugues Goosse, Vincent Rinterknecht, Claude Legentil, Raphaelle Charrassin, Georges Aumaître, Didier L. Bourlès, Karim Keddadouche
Title Evolution of the Cook Ice Cap (Kerguelen Islands) between the last centuries and 2100 ce based on cosmogenic dating and glacio-climatic modelling Type Journal
Year 2021 Publication Antarctic Science Abbreviated Journal
Volume 33 Issue 3 Pages 301-317
Keywords degree-day glaciological model future projections glacial fluctuations in situ cosmogenic chlorine-36 dating moraines sub-Antarctic islands
Abstract The Cook Ice Cap (CIC) on the sub-Antarctic Kerguelen Islands recently experienced extremely negative surface mass balance. Further deglaciation could have important impacts on endemic and invasive fauna and flora. To put this exceptional glacier evolution into a multi-centennial-scale context, we refined the evolution of the CIC over the last millennium, investigated the associated climate conditions and explored its potential evolution by 2100 ce. A glaciological model, constrained by cosmic ray exposure dating of moraines, historical documents and recent direct mass balance observations, was used to simulate the ice-cap extents during different phases of advance and retreat between the last millennium and 2100 ce. Cosmogenic dating suggests glacial advance around the early Little Ice Age (LIA), consistent with findings from other sub-Antarctic studies, and the rather cold and humid conditions brought about by the negative phase of the Southern Annular Mode (SAM). This study contributes to our currently limited understanding of palaeoclimate for the early LIA in the southern Indian Ocean. Glaciological modelling and observations confirm the recent decrease in CIC extent linked to the intensification of the SAM. Although affected by large uncertainties, future simulations suggest a complete disappearance of CIC by the end of the century.
Programme 1048
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN (up) 0954-1020, 1365-2079 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8187
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Author L A Ermert, K Sager, T Nissen-Meyer, A Fichtner
Title Multifrequency inversion of global ambient seismic sources Type Journal
Year 2021 Publication Geophysical Journal International Abbreviated Journal
Volume 225 Issue 3 Pages 1616-1623
Keywords
Abstract We develop and apply a method to constrain the space- and frequency-dependent location of ambient noise sources. This is based on ambient noise cross-correlation inversion using numerical wavefield simulations, which honour 3-D crustal and mantle structure, ocean loading and finite-frequency effects. In the frequency range from 3 to 20 mHz, our results constrain the global source distribution of the Earth’s hum, averaged over the Southern Hemisphere winter season of 9 yr. During Southern Hemisphere winter, the dominant sources are largely confined to the Southern Hemisphere, the most prominent exception being the Izu-Bonin-Mariana arc, which is the most active source region between 12 and 20 mHz. Generally, strong hum sources seem to be associated with either coastlines or bathymetric highs. In contrast, deep ocean basins are devoid of hum sources. While being based on the relatively small number of STS-1 broad-band stations that have been recording continuously from 2004 to 2013, our results demonstrate the practical feasibility of a frequency-dependent noise source inversion that accounts for the complexities of 3-D wave propagation. It may thereby improve full-waveform ambient noise inversions and our understanding of the physics of noise generation.
Programme 133
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN (up) 0956-540X ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7992
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Author Lucia Gualtieri, Etienne Bachmann, Frederik J Simons, Jeroen Tromp
Title Generation of secondary microseism Love waves: effects of bathymetry, 3-D structure and source seasonality Type Journal
Year 2021 Publication Geophysical Journal International Abbreviated Journal
Volume 226 Issue 1 Pages 192-219
Keywords
Abstract Secondary microseisms are ubiquitous ambient noise vibrations due to ocean activity, dominating worldwide seismographic records at seismic periods between 3 and 10 s. Their origin is a heterogeneous distribution of pressure fluctuations along the ocean surface. In spherically symmetric earth models, no Love surface waves are generated by such a distributed surface source. We present global-scale modelling of three-component secondary microseisms using a spectral-element method, which naturally accounts for a realistic distribution of surface sources, topography and bathymetry, and 3-D heterogeneity in Earth’s crust and mantle. Seismic Love waves emerge naturally once the system reaches steady state. The ergodic origin of Love waves allows us to model the horizontal components of secondary microseisms for the first time. Love waves mostly originate from the interaction of the seismic wavefield with heterogeneous Earth structure in which the mantle plays an important role despite the short periods involved. Bathymetry beneath the source region produces weak horizontal forces that are responsible for a weak and diffuse Love wavefield. The effect of bathymetric force splitting into radial and horizontal components is overall negligible when compared to the effect of 3-D heterogeneity. However, we observe small and well-focused Love-wave arrivals at seismographic stations in Europe due to force splitting at the steepest portion of the North Atlantic Ridge and the ocean–continent boundary. The location of the sources of Love waves is seasonal at periods shorter than about 7 s, while seasonality is lost at the longer periods. Sources of Rayleigh and Love waves from the same storm may be located very far away, indicating that energy equipartitioning might not hold in the secondary microseism period band.
Programme 133
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN (up) 0956-540X ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8016
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Author Manon Clairbaux, Paul Mathewson, Warren Porter, Jérôme Fort, Hallvard Strøm, Børge Moe, Per Fauchald, Sebastien Descamps, Hálfdán H. Helgason, Vegard S. Bråthen, Benjamin Merkel, Tycho Anker-Nilssen, Ingar S. Bringsvor, Olivier Chastel, Signe Christensen-Dalsgaard, Jóhannis Danielsen, Francis Daunt, Nina Dehnhard, Kjell Einar Erikstad, Alexey Ezhov, Maria Gavrilo, Yuri Krasnov, Magdalene Langset, Svein-H. Lorentsen, Mark Newell, Bergur Olsen, Tone K. Reiertsen, Geir Helge Systad, Thorkell L. Thórarinsson, Mark Baran, Tony Diamond, Annette L. Fayet, Michelle G. Fitzsimmons, Morten Frederiksen, Hugh G. Gilchrist, Tim Guilford, Nicholas P. Huffeldt, Mark Jessopp, Kasper L. Johansen, Amy-Lee Kouwenberg, Jannie F. Linnebjerg, Heather L. Major, Laura McFarlane Tranquilla, Mark Mallory, Flemming R. Merkel, William Montevecchi, Anders Mosbech, Aevar Petersen, David Grémillet
Title North Atlantic winter cyclones starve seabirds Type Journal
Year 2021 Publication Current Biology Abbreviated Journal
Volume 31 Issue 17 Pages 3964-3971.e3
Keywords at-sea distribution cyclones energy expenditure GLS tracking seabird migration seascape ecology
Abstract Each winter, the North Atlantic Ocean is the stage for numerous cyclones, the most severe ones leading to seabird mass-mortality events called “winter wrecks.”1, 2, 3 During these, thousands of emaciated seabird carcasses are washed ashore along European and North American coasts. Winter cyclones can therefore shape seabird population dynamics4,5 by affecting survival rates as well as the body condition of surviving individuals and thus their future reproduction. However, most often the geographic origins of impacted seabirds and the causes of their deaths remain unclear.6 We performed the first ocean-basin scale assessment of cyclone exposure in a seabird community by coupling winter tracking data for ∼1,500 individuals of five key North Atlantic seabird species (Alle alle, Fratercula arctica, Uria aalge, Uria lomvia, and Rissa tridactyla) and cyclone locations. We then explored the energetic consequences of different cyclonic conditions using a mechanistic bioenergetics model7 and tested the hypothesis that cyclones dramatically increase seabird energy requirements. We demonstrated that cyclones of high intensity impacted birds from all studied species and breeding colonies during winter but especially those aggregating in the Labrador Sea, the Davis Strait, the surroundings of Iceland, and the Barents Sea. Our broad-scale analyses suggested that cyclonic conditions do not increase seabird energy requirements, implying that they die because of the unavailability of their prey and/or their inability to feed during cyclones. Our study provides essential information on seabird cyclone exposure in a context of marked cyclone regime changes due to global warming.8
Programme 330,388
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Corporate Author Thesis Bachelor's thesis
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Series Volume Series Issue Edition
ISSN (up) 0960-9822 ISBN Medium
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Notes Approved yes
Call Number Serial 8294
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Author Minna Palmroth, Maxime Grandin, Theodoros Sarris, Eelco Doornbos, Stelios Tourgaidis, Anita Aikio, Stephan Buchert, Mark A. Clilverd, Iannis Dandouras, Roderick Heelis, Alex Hoffmann, Nickolay Ivchenko, Guram Kervalishvili, David J. Knudsen, Anna Kotova, Han-Li Liu, David M. Malaspina, Günther March, Aurélie Marchaudon, Octav Marghitu, Tomoko Matsuo, Wojciech J. Miloch, Therese Moretto-Jørgensen, Dimitris Mpaloukidis, Nils Olsen, Konstantinos Papadakis, Robert Pfaff, Panagiotis Pirnaris, Christian Siemes, Claudia Stolle, Jonas Suni, Jose van den IJssel, Pekka T. Verronen, Pieter Visser, Masatoshi Yamauchi
Title Lower-thermosphere–ionosphere (LTI) quantities: current status of measuring techniques and models Type Journal
Year 2021 Publication Annales Geophysicae Abbreviated Journal
Volume 39 Issue 1 Pages 189-237
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Abstract

Abstract. The lower-thermosphere–ionosphere (LTI) system consists of the upper atmosphere and the lower part of the ionosphere and as such comprises a complex system coupled to both the atmosphere below and space above. The atmospheric part of the LTI is dominated by laws of continuum fluid dynamics and chemistry, while the ionosphere is a plasma system controlled by electromagnetic forces driven by the magnetosphere, the solar wind, as well as the wind dynamo. The LTI is hence a domain controlled by many different physical processes. However, systematic in situ measurements within this region are severely lacking, although the LTI is located only 80 to 200 km above the surface of our planet. This paper reviews the current state of the art in measuring the LTI, either in situ or by several different remote-sensing methods. We begin by outlining the open questions within the LTI requiring high-quality in situ measurements, before reviewing directly observable parameters and their most important derivatives. The motivation for this review has arisen from the recent retention of the Daedalus mission as one among three competing mission candidates within the European Space Agency (ESA) Earth Explorer 10 Programme. However, this paper intends to cover the LTI parameters such that it can be used as a background scientific reference for any mission targeting in situ observations of the LTI.

Programme 312
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ISSN (up) 0992-7689 ISBN Medium
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Notes Approved yes
Call Number Serial 7951
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Author Charlène Gémard, Víctor Planas-Bielsa, Francesco Bonadonna, Thierry Aubin
Title Contextual variations in calls of two nonoscine birds: the blue petrel Halobaena caerulea and the Antarctic prion Pachyptila desolata Type Journal
Year 2021 Publication Behavioral Ecology Abbreviated Journal
Volume 32 Issue 4 Pages 769-779
Keywords
Abstract Bird vocalizations are critical cues in social interactions as they convey temporary information varying with the social context, for example, the signaler motivation when facing a rival or a potential mate. To date, literature mainly focused on learning birds. Burrowing petrels (Procellariidae) are nonlearning birds with a limited vocal repertoire. Bachelor males communicate with conspecifics with a single call emitted in three situations: in the absence of a certain auditory (spontaneous calls), toward females (female-directed calls), and toward males (male-directed calls). We first hypothesized that, although the call structure is preserved, temporal and spectral parameters vary between the three call types of bachelor males, translating different motivations (Motivation Hypothesis). To go further, we hypothesized that acoustic variations in male-directed calls indicate the signaler’s aggressive motivation and, therefore, the variations are similar whether calls are produced by breeder or bachelor males (Breeding Status Hypothesis). We tested the two hypotheses performing field playback experiments on two petrel species: the blue petrel (Halobaena caerulea) and the Antarctic prion (Pachyptila desolata). Despite the obvious call stereotypy, we observed temporal variations and frequency shifts when males react to a female or a male, which may translate the sexual or aggressive motivation of the signaler. Furthermore, the similarity of variations in male-directed calls of both breeder and bachelor males suggests the aggressive motivation. So far, vocal plasticity in nonlearning birds has been greatly underestimated. Here, we highlighted the expression of different motivations through vocal variations and the ability to produce frequency variations in species with genetically coded vocalizations.
Programme 354
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ISSN (up) 1045-2249 ISBN Medium
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Notes Approved yes
Call Number Serial 8259
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