Articles | Volume 13, issue 9
https://doi.org/10.5194/cp-13-1269-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/cp-13-1269-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
28 Sep 2017
Research article |
| 28 Sep 2017
The De Long Trough: a newly discovered glacial trough on the East Siberian continental margin
Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
Jan Backman
Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
Natalia Barrientos
Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
Thomas M. Cronin
US Geological Survey MS926A, Reston, Virginia 20192, USA
Laura Gemery
US Geological Survey MS926A, Reston, Virginia 20192, USA
Nina Kirchner
Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
Department of Physical Geography (NG), Stockholm University, 10691, Stockholm, Sweden
Larry A. Mayer
Center for Coastal and Ocean Mapping, University of New Hampshire, Durham, New Hampshire 03824, USA
Johan Nilsson
Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
Department of Meteorology, Stockholm University, 10691, Stockholm, Sweden
Riko Noormets
University Centre in Svalbard (UNIS), P.O. Box 156, 9171, Longyearbyen, Svalbard, Norway
Christof Pearce
Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
Department of Geoscience, Aarhus University, 8000, Aarhus, Denmark
Igor Semiletov
Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences, 690041, Vladivostok, Russia
Tomsk National Research Polytechnic University, 634050, Tomsk, Russia
Christian Stranne
Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
Center for Coastal and Ocean Mapping, University of New Hampshire, Durham, New Hampshire 03824, USA
Martin Jakobsson
Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
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Felicity Alice Holmes, Jamie Barnett, Henning Åkesson, Mathieu Morlighem, Johan Nilsson, Nina Kirchner, and Martin Jakobsson
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Erik Gustafsson, Bo G. Gustafsson, Martijn Hermans, Christoph Humborg, and Christian Stranne
Geosci. Model Dev., 17, 7157–7179, https://doi.org/10.5194/gmd-17-7157-2024, https://doi.org/10.5194/gmd-17-7157-2024, 2024
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Adrian Dye, Robert Bryant, Francesca Falcini, Joseph Mallalieu, Miles Dimbleby, Michael Beckwith, David Rippin, and Nina Kirchner
EGUsphere, https://doi.org/10.5194/egusphere-2024-2510, https://doi.org/10.5194/egusphere-2024-2510, 2024
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Lasse Z. Jensen, Julie K. Simonsen, Ada Pastor, Christof Pearce, Per Nørnberg, Lars Chresten Lund-Hansen, Kai Finster, and Tina Šantl-Temkiv
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The Cryosphere, 18, 3415–3431, https://doi.org/10.5194/tc-18-3415-2024, https://doi.org/10.5194/tc-18-3415-2024, 2024
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Allison P. Lepp, Lauren E. Miller, John B. Anderson, Matt O'Regan, Monica C. M. Winsborrow, James A. Smith, Claus-Dieter Hillenbrand, Julia S. Wellner, Lindsay O. Prothro, and Evgeny A. Podolskiy
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Flor Vermassen, Clare Bird, Tirza M. Weitkamp, Kate F. Darling, Hanna Farnelid, Céline Heuzé, Allison Y. Hsiang, Salar Karam, Christian Stranne, Marcus Sundbom, and Helen K. Coxall
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Julia Muchowski, Martin Jakobsson, Lars Umlauf, Lars Arneborg, Bo Gustafsson, Peter Holtermann, Christoph Humborg, and Christian Stranne
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Christof Pearce, Karen Søby Özdemir, Ronja Forchhammer Mathiasen, Henrieka Detlef, and Jesper Olsen
Geochronology, 5, 451–465, https://doi.org/10.5194/gchron-5-451-2023, https://doi.org/10.5194/gchron-5-451-2023, 2023
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Reliable chronologies lie at the base of paleoclimatological reconstructions. When working with marine sediment cores, the most common dating tool for recent sediments is radiocarbon, but this requires calibration to convert it to calendar ages. This calibration requires knowledge of the marine radiocarbon reservoir age, and this is known to vary in space and time. In this study we provide 92 new radiocarbon measurements to improve our knowledge of the reservoir age around Greenland.
Abhay Prakash, Qin Zhou, Tore Hattermann, and Nina Kirchner
The Cryosphere, 17, 5255–5281, https://doi.org/10.5194/tc-17-5255-2023, https://doi.org/10.5194/tc-17-5255-2023, 2023
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Sea ice arch formation in the Nares Strait has shielded the Petermann Glacier ice shelf from enhanced basal melting. However, with the sustained decline of the Arctic sea ice predicted to continue, the ice shelf is likely to be exposed to a year-round mobile and thin sea ice cover. In such a scenario, our modelled results show that elevated temperatures, and more importantly, a stronger ocean circulation in the ice shelf cavity, could result in up to two-thirds increase in basal melt.
Johan Nilsson, Eef van Dongen, Martin Jakobsson, Matt O'Regan, and Christian Stranne
The Cryosphere, 17, 2455–2476, https://doi.org/10.5194/tc-17-2455-2023, https://doi.org/10.5194/tc-17-2455-2023, 2023
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We investigate how topographical sills suppress basal glacier melt in Greenlandic fjords. The basal melt drives an exchange flow over the sill, but there is an upper flow limit set by the Atlantic Water features outside the fjord. If this limit is reached, the flow enters a new regime where the melt is suppressed and its sensitivity to the Atlantic Water temperature is reduced.
Gabriel West, Darrell S. Kaufman, Martin Jakobsson, and Matt O'Regan
Geochronology, 5, 285–299, https://doi.org/10.5194/gchron-5-285-2023, https://doi.org/10.5194/gchron-5-285-2023, 2023
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We report aspartic and glutamic acid racemization analyses on Neogloboquadrina pachyderma and Cibicidoides wuellerstorfi from the Arctic Ocean (AO). The rates of racemization in the species are compared. Calibrating the rate of racemization in C. wuellerstorfi for the past 400 ka allows the estimation of sample ages from the central AO. Estimated ages are older than existing age assignments (as previously observed for N. pachyderma), confirming that differences are not due to taxonomic effects.
Felicity A. Holmes, Eef van Dongen, Riko Noormets, Michał Pętlicki, and Nina Kirchner
The Cryosphere, 17, 1853–1872, https://doi.org/10.5194/tc-17-1853-2023, https://doi.org/10.5194/tc-17-1853-2023, 2023
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Glaciers which end in bodies of water can lose mass through melting below the waterline, as well as by the breaking off of icebergs. We use a numerical model to simulate the breaking off of icebergs at Kronebreen, a glacier in Svalbard, and find that both melting below the waterline and tides are important for iceberg production. In addition, we compare the modelled glacier front to observations and show that melting below the waterline can lead to undercuts of up to around 25 m.
Alistair J. Monteath, Matthew S. M. Bolton, Jordan Harvey, Marit-Solveig Seidenkrantz, Christof Pearce, and Britta Jensen
Geochronology, 5, 229–240, https://doi.org/10.5194/gchron-5-229-2023, https://doi.org/10.5194/gchron-5-229-2023, 2023
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Accurately dating ocean cores is challenging because the radiocarbon age of water masses varies substantially. We identify ash fragments from eruptions more than 4000 km from their source and use these time markers to develop a new age–depth model for an ocean core in Placentia Bay, North Atlantic. Our results show that the radiocarbon age of waters masses in the bay varied considerably during the last 10 000 years and highlight the potential of using ultra-distal ash deposits in this region.
Jesse R. Farmer, Katherine J. Keller, Robert K. Poirier, Gary S. Dwyer, Morgan F. Schaller, Helen K. Coxall, Matt O'Regan, and Thomas M. Cronin
Clim. Past, 19, 555–578, https://doi.org/10.5194/cp-19-555-2023, https://doi.org/10.5194/cp-19-555-2023, 2023
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Oxygen isotopes are used to date marine sediments via similar large-scale ocean patterns over glacial cycles. However, the Arctic Ocean exhibits a different isotope pattern, creating uncertainty in the timing of past Arctic climate change. We find that the Arctic Ocean experienced large local oxygen isotope changes over glacial cycles. We attribute this to a breakdown of stratification during ice ages that allowed for a unique low isotope value to characterize the ice age Arctic Ocean.
Raisa Alatarvas, Matt O'Regan, and Kari Strand
Clim. Past, 18, 1867–1881, https://doi.org/10.5194/cp-18-1867-2022, https://doi.org/10.5194/cp-18-1867-2022, 2022
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This research contributes to efforts solving research questions related to the history of ice sheet decay in the Northern Hemisphere. The East Siberian continental margin sediments provide ideal material for identifying the mineralogical signature of ice sheet derived material. Heavy mineral analysis from marine glacial sediments from the De Long Trough and Lomonosov Ridge was used in interpreting the activity of the East Siberian Ice Sheet in the Arctic region.
H. E. Markus Meier, Madline Kniebusch, Christian Dieterich, Matthias Gröger, Eduardo Zorita, Ragnar Elmgren, Kai Myrberg, Markus P. Ahola, Alena Bartosova, Erik Bonsdorff, Florian Börgel, Rene Capell, Ida Carlén, Thomas Carlund, Jacob Carstensen, Ole B. Christensen, Volker Dierschke, Claudia Frauen, Morten Frederiksen, Elie Gaget, Anders Galatius, Jari J. Haapala, Antti Halkka, Gustaf Hugelius, Birgit Hünicke, Jaak Jaagus, Mart Jüssi, Jukka Käyhkö, Nina Kirchner, Erik Kjellström, Karol Kulinski, Andreas Lehmann, Göran Lindström, Wilhelm May, Paul A. Miller, Volker Mohrholz, Bärbel Müller-Karulis, Diego Pavón-Jordán, Markus Quante, Marcus Reckermann, Anna Rutgersson, Oleg P. Savchuk, Martin Stendel, Laura Tuomi, Markku Viitasalo, Ralf Weisse, and Wenyan Zhang
Earth Syst. Dynam., 13, 457–593, https://doi.org/10.5194/esd-13-457-2022, https://doi.org/10.5194/esd-13-457-2022, 2022
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Based on the Baltic Earth Assessment Reports of this thematic issue in Earth System Dynamics and recent peer-reviewed literature, current knowledge about the effects of global warming on past and future changes in the climate of the Baltic Sea region is summarised and assessed. The study is an update of the Second Assessment of Climate Change (BACC II) published in 2015 and focuses on the atmosphere, land, cryosphere, ocean, sediments, and the terrestrial and marine biosphere.
Teodora Pados-Dibattista, Christof Pearce, Henrieka Detlef, Jørgen Bendtsen, and Marit-Solveig Seidenkrantz
Clim. Past, 18, 103–127, https://doi.org/10.5194/cp-18-103-2022, https://doi.org/10.5194/cp-18-103-2022, 2022
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We carried out foraminiferal, stable isotope, and sedimentological analyses of a marine sediment core retrieved from the Northeast Greenland shelf. This region is highly sensitive to climate variability because it is swept by the East Greenland Current, which is the main pathway for sea ice and cold waters that exit the Arctic Ocean. The palaeoceanographic reconstruction reveals significant variations in the water masses and in the strength of the East Greenland Current over the last 9400 years.
Jaclyn Clement Kinney, Karen M. Assmann, Wieslaw Maslowski, Göran Björk, Martin Jakobsson, Sara Jutterström, Younjoo J. Lee, Robert Osinski, Igor Semiletov, Adam Ulfsbo, Irene Wåhlström, and Leif G. Anderson
Ocean Sci., 18, 29–49, https://doi.org/10.5194/os-18-29-2022, https://doi.org/10.5194/os-18-29-2022, 2022
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We use data crossing Herald Canyon in the Chukchi Sea collected in 2008 and 2014 together with numerical modelling to investigate the circulation in the western Chukchi Sea. A large fraction of water from the Chukchi Sea enters the East Siberian Sea south of Wrangel Island and circulates in an anticyclonic direction around the island. To assess the differences between years, we use numerical modelling results, which show that high-frequency variability dominates the flow in Herald Canyon.
Henrieka Detlef, Brendan Reilly, Anne Jennings, Mads Mørk Jensen, Matt O'Regan, Marianne Glasius, Jesper Olsen, Martin Jakobsson, and Christof Pearce
The Cryosphere, 15, 4357–4380, https://doi.org/10.5194/tc-15-4357-2021, https://doi.org/10.5194/tc-15-4357-2021, 2021
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Here we examine the Nares Strait sea ice dynamics over the last 7000 years and their implications for the late Holocene readvance of the floating part of Petermann Glacier. We propose that the historically observed sea ice dynamics are a relatively recent feature, while most of the mid-Holocene was marked by variable sea ice conditions in Nares Strait. Nonetheless, major advances of the Petermann ice tongue were preceded by a shift towards harsher sea ice conditions in Nares Strait.
Matt O'Regan, Thomas M. Cronin, Brendan Reilly, Aage Kristian Olsen Alstrup, Laura Gemery, Anna Golub, Larry A. Mayer, Mathieu Morlighem, Matthias Moros, Ole L. Munk, Johan Nilsson, Christof Pearce, Henrieka Detlef, Christian Stranne, Flor Vermassen, Gabriel West, and Martin Jakobsson
The Cryosphere, 15, 4073–4097, https://doi.org/10.5194/tc-15-4073-2021, https://doi.org/10.5194/tc-15-4073-2021, 2021
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Ryder Glacier is a marine-terminating glacier in north Greenland discharging ice into the Lincoln Sea. Here we use marine sediment cores to reconstruct its retreat and advance behavior through the Holocene. We show that while Sherard Osborn Fjord has a physiography conducive to glacier and ice tongue stability, Ryder still retreated more than 40 km inland from its current position by the Middle Holocene. This highlights the sensitivity of north Greenland's marine glaciers to climate change.
Jannik Martens, Evgeny Romankevich, Igor Semiletov, Birgit Wild, Bart van Dongen, Jorien Vonk, Tommaso Tesi, Natalia Shakhova, Oleg V. Dudarev, Denis Kosmach, Alexander Vetrov, Leopold Lobkovsky, Nikolay Belyaev, Robie W. Macdonald, Anna J. Pieńkowski, Timothy I. Eglinton, Negar Haghipour, Salve Dahle, Michael L. Carroll, Emmelie K. L. Åström, Jacqueline M. Grebmeier, Lee W. Cooper, Göran Possnert, and Örjan Gustafsson
Earth Syst. Sci. Data, 13, 2561–2572, https://doi.org/10.5194/essd-13-2561-2021, https://doi.org/10.5194/essd-13-2561-2021, 2021
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The paper describes the establishment, structure and current status of the first Circum-Arctic Sediment CArbon DatabasE (CASCADE), which is a scientific effort to harmonize and curate all published and unpublished data of carbon, nitrogen, carbon isotopes, and terrigenous biomarkers in sediments of the Arctic Ocean in one database. CASCADE will enable a variety of studies of the Arctic carbon cycle and thus contribute to a better understanding of how climate change affects the Arctic.
Gong Cheng, Nina Kirchner, and Per Lötstedt
The Cryosphere, 15, 715–742, https://doi.org/10.5194/tc-15-715-2021, https://doi.org/10.5194/tc-15-715-2021, 2021
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We present an inverse modeling approach to improve the understanding of spatiotemporally variable processes at the inaccessible base of an ice sheet by determining the sensitivity of direct surface observations to perturbations of basal conditions. Time dependency is proved to be important in these types of problems. The effect of perturbations is analyzed based on analytical and numerical solutions.
Colin Ware, Larry Mayer, Paul Johnson, Martin Jakobsson, and Vicki Ferrini
Geosci. Instrum. Method. Data Syst., 9, 375–384, https://doi.org/10.5194/gi-9-375-2020, https://doi.org/10.5194/gi-9-375-2020, 2020
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Geographic coordinates (latitude and longitude) are widely used in geospatial applications, and terrains are often defined by regular grids in geographic coordinates. However, because of convergence of lines of longitude near the poles there is oversampling in the latitude (zonal) direction. Also, there is no standard way of defining a hierarchy of grids to consistently deal with data having different spatial resolutions. The proposed global geographic grid system solves both problems.
Alexander Osadchiev, Igor Medvedev, Sergey Shchuka, Mikhail Kulikov, Eduard Spivak, Maria Pisareva, and Igor Semiletov
Ocean Sci., 16, 781–798, https://doi.org/10.5194/os-16-781-2020, https://doi.org/10.5194/os-16-781-2020, 2020
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The Yenisei and Khatanga rivers are among the largest estuarine rivers that inflow to the Arctic Ocean. Discharge of the Yenisei River is 1 order of magnitude larger than that of the Khatanga River. However, spatial scales of buoyant plumes formed by freshwater runoff from the Yenisei and Khatanga gulfs are similar. This feature is caused by intense tidal mixing in the Khatanga Gulf, which causes formation of the diluted and therefore anomalously deep and large Khatanga plume.
Katrine Elnegaard Hansen, Jacques Giraudeau, Lukas Wacker, Christof Pearce, and Marit-Solveig Seidenkrantz
Clim. Past, 16, 1075–1095, https://doi.org/10.5194/cp-16-1075-2020, https://doi.org/10.5194/cp-16-1075-2020, 2020
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In this study, we present RainNet, a deep convolutional neural network for radar-based precipitation nowcasting, which was trained to predict continuous precipitation intensities at a lead time of 5 min. RainNet significantly outperformed the benchmark models at all lead times up to 60 min. Yet an undesirable property of RainNet predictions is the level of spatial smoothing. Obviously, RainNet learned an optimal level of smoothing to produce a nowcast at 5 min lead time.
Francesco Muschitiello, Matt O'Regan, Jannik Martens, Gabriel West, Örjan Gustafsson, and Martin Jakobsson
Geochronology, 2, 81–91, https://doi.org/10.5194/gchron-2-81-2020, https://doi.org/10.5194/gchron-2-81-2020, 2020
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In this study we present a new marine chronology of the last ~30 000 years for a sediment core retrieved from the central Arctic Ocean. Our new chronology reveals substantially faster sedimentation rates during the end of the last glacial cycle, the Last Glacial Maximum, and deglaciation than previously reported, thus implying a substantial re-interpretation of paleoceanographic reconstructions from this sector of the Arctic Ocean.
Zhongshi Zhang, Qing Yan, Ran Zhang, Florence Colleoni, Gilles Ramstein, Gaowen Dai, Martin Jakobsson, Matt O'Regan, Stefan Liess, Denis-Didier Rousseau, Naiqing Wu, Elizabeth J. Farmer, Camille Contoux, Chuncheng Guo, Ning Tan, and Zhengtang Guo
Clim. Past Discuss., https://doi.org/10.5194/cp-2020-38, https://doi.org/10.5194/cp-2020-38, 2020
Manuscript not accepted for further review
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Whether an ice sheet once grew over Northeast Siberia-Beringia has been debated for decades. By comparing climate modelling with paleoclimate and glacial records from around the North Pacific, this study shows that the Laurentide-Eurasia-only ice sheet configuration fails in explaining these records, while a scenario involving the ice sheet over Northeast Siberia-Beringia succeeds. It highlights the complexity in glacial climates and urges new investigations across Northeast Siberia-Beringia.
Kelly A. Hogan, Martin Jakobsson, Larry Mayer, Brendan T. Reilly, Anne E. Jennings, Joseph S. Stoner, Tove Nielsen, Katrine J. Andresen, Egon Nørmark, Katrien A. Heirman, Elina Kamla, Kevin Jerram, Christian Stranne, and Alan Mix
The Cryosphere, 14, 261–286, https://doi.org/10.5194/tc-14-261-2020, https://doi.org/10.5194/tc-14-261-2020, 2020
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Glacial sediments in fjords hold a key record of environmental and ice dynamic changes during ice retreat. Here we use a comprehensive geophysical survey from the Petermann Fjord system in NW Greenland to map these sediments, identify depositional processes and calculate glacial erosion rates for the retreating palaeo-Petermann ice stream. Ice streaming is the dominant control on glacial erosion rates which vary by an order of magnitude during deglaciation and are in line with modern rates.
Martin Jakobsson, Matt O'Regan, Carl-Magnus Mörth, Christian Stranne, Elizabeth Weidner, Jim Hansson, Richard Gyllencreutz, Christoph Humborg, Tina Elfwing, Alf Norkko, Joanna Norkko, Björn Nilsson, and Arne Sjöström
Earth Surf. Dynam., 8, 1–15, https://doi.org/10.5194/esurf-8-1-2020, https://doi.org/10.5194/esurf-8-1-2020, 2020
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We studied coastal sea floor terraces in parts of the Baltic Sea using various types of sonar data, sediment cores, and video. Terraces (~1 m high, > 100 m long) are widespread in depths < 15 m and are formed in glacial clay. Our study supports an origin from groundwater flow through silty layers, undermining overlying layers when discharged at the sea floor. Submarine groundwater discharge like this may be a significant source of freshwater to the Baltic Sea that needs to be studied further.
Gabriel West, Darrell S. Kaufman, Francesco Muschitiello, Matthias Forwick, Jens Matthiessen, Jutta Wollenburg, and Matt O'Regan
Geochronology, 1, 53–67, https://doi.org/10.5194/gchron-1-53-2019, https://doi.org/10.5194/gchron-1-53-2019, 2019
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We report amino acid racemization analyses of foraminifera from well-dated sediment cores from the Yermak Plateau, Arctic Ocean. Sample ages are compared with model predictions, revealing that the rates of racemization generally conform to a global compilation of racemization rates at deep-sea sites. These results highlight the need for further studies to test and explain the origin of the purportedly high rate of racemization indicated by previous analyses of central Arctic sediments.
Christian Stranne, Matt O'Regan, Martin Jakobsson, Volker Brüchert, and Marcelo Ketzer
Solid Earth, 10, 1541–1554, https://doi.org/10.5194/se-10-1541-2019, https://doi.org/10.5194/se-10-1541-2019, 2019
Martin Jakobsson, Christian Stranne, Matt O'Regan, Sarah L. Greenwood, Bo Gustafsson, Christoph Humborg, and Elizabeth Weidner
Ocean Sci., 15, 905–924, https://doi.org/10.5194/os-15-905-2019, https://doi.org/10.5194/os-15-905-2019, 2019
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The bottom topography of the Baltic Sea is analysed using the digital depth model from the European Marine Observation and Data Network (EMODnet) published in 2018. Analyses include depth distribution vs. area and seafloor depth variation on a kilometre scale. The limits for the Baltic Sea and analysed sub-basins are from HELCOM. EMODnet is compared with the previously most widely used depth model and the area of deep water exchange between the Bothnian Sea and the Northern Baltic Proper.
Sarah Conrad, Johan Ingri, Johan Gelting, Fredrik Nordblad, Emma Engström, Ilia Rodushkin, Per S. Andersson, Don Porcelli, Örjan Gustafsson, Igor Semiletov, and Björn Öhlander
Biogeosciences, 16, 1305–1319, https://doi.org/10.5194/bg-16-1305-2019, https://doi.org/10.5194/bg-16-1305-2019, 2019
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Iron analysis of the particulate, colloidal, and truly dissolved fractions along the Lena River freshwater plume showed that the particulate iron dominates close to the coast. Over 99 % particulate and about 90 % colloidal iron were lost, while the truly dissolved phase was almost constant. Iron isotopes suggest that the shelf acts as a sink for particles and colloids with negative iron isotope values, while colloids with positive iron isotope values travel further out into the Arctic Ocean.
Eef C. H. van Dongen, Nina Kirchner, Martin B. van Gijzen, Roderik S. W. van de Wal, Thomas Zwinger, Gong Cheng, Per Lötstedt, and Lina von Sydow
Geosci. Model Dev., 11, 4563–4576, https://doi.org/10.5194/gmd-11-4563-2018, https://doi.org/10.5194/gmd-11-4563-2018, 2018
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Ice flow forced by gravity is governed by the full Stokes (FS) equations, which are computationally expensive to solve. Therefore, approximations to the FS equations are used, especially when modeling an ice sheet on long time spans. Here, we report a combination of an approximation with the FS equations that allows simulating the dynamics of ice sheets over long time spans without introducing artifacts caused by application of approximations in parts of the domain where they are not valid.
Birgit Wild, Natalia Shakhova, Oleg Dudarev, Alexey Ruban, Denis Kosmach, Vladimir Tumskoy, Tommaso Tesi, Hanna Joß, Helena Alexanderson, Martin Jakobsson, Alexey Mazurov, Igor Semiletov, and Örjan Gustafsson
The Cryosphere Discuss., https://doi.org/10.5194/tc-2018-229, https://doi.org/10.5194/tc-2018-229, 2018
Revised manuscript not accepted
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The thaw and degradation of subsea permafrost on the Arctic Ocean shelves is one of the key uncertainties concerning natural greenhouse gas emissions since difficult access limits the availability of observational data. In this study, we describe sediment properties and age constraints of a unique set of three subsea permafrost cores from the East Siberian Arctic Shelf, as well as content, origin and degradation state of organic matter at the current thaw front.
Robert B. Sparkes, Melissa Maher, Jerome Blewett, Ayça Doğrul Selver, Örjan Gustafsson, Igor P. Semiletov, and Bart E. van Dongen
The Cryosphere, 12, 3293–3309, https://doi.org/10.5194/tc-12-3293-2018, https://doi.org/10.5194/tc-12-3293-2018, 2018
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Ongoing climate change in the Siberian Arctic region has the potential to release large amounts of carbon, currently stored in permafrost, to the Arctic Shelf. Degradation can release this to the atmosphere as greenhouse gas. We used Raman spectroscopy to analyse a fraction of this carbon, carbonaceous material, a group that includes coal, lignite and graphite. We were able to trace this carbon from the river mouths and coastal erosion sites across the Arctic shelf for hundreds of kilometres.
Zhongshi Zhang, Qing Yan, Elizabeth J. Farmer, Camille Li, Gilles Ramstein, Terence Hughes, Martin Jakobsson, Matt O'Regan, Ran Zhang, Ning Tan, Camille Contoux, Christophe Dumas, and Chuncheng Guo
Clim. Past Discuss., https://doi.org/10.5194/cp-2018-79, https://doi.org/10.5194/cp-2018-79, 2018
Revised manuscript not accepted
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Our study challenges the widely accepted idea that the Laurentide-Eurasian ice sheets gradually extended across North America and Northwest Eurasia, and suggests the growth of the NH ice sheets is much more complicated. We find climate feedbacks regulate the distribution of the NH ice sheets, producing swings between two distinct ice sheet configurations: the Laurentide-Eurasian and a circum-Arctic configuration, where large ice sheets existed over Northeast Siberia and the Canadian Rockies.
Christian Stranne, Larry Mayer, Martin Jakobsson, Elizabeth Weidner, Kevin Jerram, Thomas C. Weber, Leif G. Anderson, Johan Nilsson, Göran Björk, and Katarina Gårdfeldt
Ocean Sci., 14, 503–514, https://doi.org/10.5194/os-14-503-2018, https://doi.org/10.5194/os-14-503-2018, 2018
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The ocean surface mixed layer depth (MLD) is an important parameter within several research disciplines, as variations in the MLD influence air–sea CO2 exchange and ocean primary production. A new method is presented in which acoustic mapping of the MLD is done remotely by means of echo sounders. This method allows for observations of high-frequency variability in the MLD, as horizontal and temporal resolutions can be increased by orders of magnitude compared to traditional in situ measurements.
Svetlana P. Pugach, Irina I. Pipko, Natalia E. Shakhova, Evgeny A. Shirshin, Irina V. Perminova, Örjan Gustafsson, Valery G. Bondur, Alexey S. Ruban, and Igor P. Semiletov
Ocean Sci., 14, 87–103, https://doi.org/10.5194/os-14-87-2018, https://doi.org/10.5194/os-14-87-2018, 2018
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This paper explores the possibility of using CDOM and its spectral parameters to identify the different biogeochemical regimes on the ESAS. The strong correlation between DOC and CDOM values in the surface shelf waters influenced by terrigenous discharge indicates that it is feasible to estimate DOC content from CDOM fluorescence assessed in situ. The direct estimation of DOM optical parameters in the surface ESAS waters provided by this study will be useful for validating remote sensing data.
Volker Brüchert, Lisa Bröder, Joanna E. Sawicka, Tommaso Tesi, Samantha P. Joye, Xiaole Sun, Igor P. Semiletov, and Vladimir A. Samarkin
Biogeosciences, 15, 471–490, https://doi.org/10.5194/bg-15-471-2018, https://doi.org/10.5194/bg-15-471-2018, 2018
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We determined the aerobic and anaerobic degradation rates of land- and marine-derived organic material in East Siberian shelf sediment. Marine plankton-derived organic carbon was the main source for the oxic dissolved carbon dioxide production, whereas terrestrial organic material significantly contributed to the production of carbon dioxide under anoxic conditions. Our direct degradation rate measurements provide new constraints for the present-day Arctic marine carbon budget.
Göran Björk, Martin Jakobsson, Karen Assmann, Leif G. Andersson, Johan Nilsson, Christian Stranne, and Larry Mayer
Ocean Sci., 14, 1–13, https://doi.org/10.5194/os-14-1-2018, https://doi.org/10.5194/os-14-1-2018, 2018
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This study presents detailed bathymetric data along with hydrographic data at two deep passages across the Lomonosov Ridge in the Arctic Ocean. The southern channel is relatively smooth with a sill depth close to 1700 m. Hydrographic data reveals an eastward flow in the southern part and opposite in the northern part. The northern passage is characterized by a narrow and steep ridge with a sill depth of 1470 m. Here, water exchange appears to occur in well-defined but irregular vertical layers.
Irina I. Pipko, Svetlana P. Pugach, Igor P. Semiletov, Leif G. Anderson, Natalia E. Shakhova, Örjan Gustafsson, Irina A. Repina, Eduard A. Spivak, Alexander N. Charkin, Anatoly N. Salyuk, Kseniia P. Shcherbakova, Elena V. Panova, and Oleg V. Dudarev
Ocean Sci., 13, 997–1016, https://doi.org/10.5194/os-13-997-2017, https://doi.org/10.5194/os-13-997-2017, 2017
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The study of the outer shelf and the continental slope waters of the Eurasian Arctic seas has revealed a general trend in the surface pCO2 distribution, which manifested as an increase in pCO2 values eastward. It has been shown that the influence of terrestrial discharge on the carbonate system of East Siberian Arctic sea surface waters is not limited to the shallow shelf and that contemporary climate change impacts the carbon cycle of the Eurasian Arctic Ocean and influences air–sea CO2 flux.
Laura Gemery, Thomas M. Cronin, Robert K. Poirier, Christof Pearce, Natalia Barrientos, Matt O'Regan, Carina Johansson, Andrey Koshurnikov, and Martin Jakobsson
Clim. Past, 13, 1473–1489, https://doi.org/10.5194/cp-13-1473-2017, https://doi.org/10.5194/cp-13-1473-2017, 2017
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Continuous, highly abundant and well-preserved fossil ostracodes were studied from radiocarbon-dated sediment cores collected on the Lomonosov Ridge (Arctic Ocean) that indicate varying oceanographic conditions during the last ~50 kyr. Ostracode assemblages from cores taken during the SWERUS-C3 2014 Expedition, Leg 2, reflect paleoenvironmental changes during glacial, deglacial, and interglacial transitions, including changes in sea-ice cover and Atlantic Water inflow into the Eurasian Basin.
Alexander N. Charkin, Michiel Rutgers van der Loeff, Natalia E. Shakhova, Örjan Gustafsson, Oleg V. Dudarev, Maxim S. Cherepnev, Anatoly N. Salyuk, Andrey V. Koshurnikov, Eduard A. Spivak, Alexey Y. Gunar, Alexey S. Ruban, and Igor P. Semiletov
The Cryosphere, 11, 2305–2327, https://doi.org/10.5194/tc-11-2305-2017, https://doi.org/10.5194/tc-11-2305-2017, 2017
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This study tests the hypothesis that SGD exists in the Siberian Arctic shelf seas, but its dynamics may be largely controlled by complicated geocryological conditions such as permafrost. The permafrost cements rocks, forms a confining bed, and as a result makes it difficult for the groundwater escape to the shelf surface. However, the discovery of subterranean outcrops of groundwater springs in the Buor-Khaya Gulf are clear evidence that a groundwater flow system exists in the environment.
Kirsi Keskitalo, Tommaso Tesi, Lisa Bröder, August Andersson, Christof Pearce, Martin Sköld, Igor P. Semiletov, Oleg V. Dudarev, and Örjan Gustafsson
Clim. Past, 13, 1213–1226, https://doi.org/10.5194/cp-13-1213-2017, https://doi.org/10.5194/cp-13-1213-2017, 2017
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In this study we investigate land-to-ocean transfer and the fate of permafrost carbon in the East Siberian Sea from the early Holocene until the present day. Our results suggest that there was a high input of terrestrial organic carbon to the East Siberian Sea during the last glacial–interglacial period caused by permafrost destabilisation. This material was mainly characterised as relict Pleistocene permafrost deposited via coastal erosion as a result of the sea level rise.
Tommaso Tesi, Marc C. Geibel, Christof Pearce, Elena Panova, Jorien E. Vonk, Emma Karlsson, Joan A. Salvado, Martin Kruså, Lisa Bröder, Christoph Humborg, Igor Semiletov, and Örjan Gustafsson
Ocean Sci., 13, 735–748, https://doi.org/10.5194/os-13-735-2017, https://doi.org/10.5194/os-13-735-2017, 2017
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Recent Arctic studies suggest that sea-ice decline and permafrost thawing will affect the phytoplankton in the Arctic Ocean. However, in what way the plankton composition will change as the warming proceeds remains elusive. Here we show that the carbon composition of plankton might change as a function of the enhanced terrestrial organic carbon supply and progressive sea-ice thawing.
Thomas M. Cronin, Matt O'Regan, Christof Pearce, Laura Gemery, Michael Toomey, Igor Semiletov, and Martin Jakobsson
Clim. Past, 13, 1097–1110, https://doi.org/10.5194/cp-13-1097-2017, https://doi.org/10.5194/cp-13-1097-2017, 2017
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Global sea level rise during the last deglacial flooded the Siberian continental shelf in the Arctic Ocean. Sediment cores, radiocarbon dating, and microfossils show that the regional sea level in the Arctic rose rapidly from about 12 500 to 10 700 years ago. Regional sea level history on the Siberian shelf differs from the global deglacial sea level rise perhaps due to regional vertical adjustment resulting from the growth and decay of ice sheets.
Jorien E. Vonk, Tommaso Tesi, Lisa Bröder, Henry Holmstrand, Gustaf Hugelius, August Andersson, Oleg Dudarev, Igor Semiletov, and Örjan Gustafsson
The Cryosphere, 11, 1879–1895, https://doi.org/10.5194/tc-11-1879-2017, https://doi.org/10.5194/tc-11-1879-2017, 2017
Martin Jakobsson, Christof Pearce, Thomas M. Cronin, Jan Backman, Leif G. Anderson, Natalia Barrientos, Göran Björk, Helen Coxall, Agatha de Boer, Larry A. Mayer, Carl-Magnus Mörth, Johan Nilsson, Jayne E. Rattray, Christian Stranne, Igor Semiletov, and Matt O'Regan
Clim. Past, 13, 991–1005, https://doi.org/10.5194/cp-13-991-2017, https://doi.org/10.5194/cp-13-991-2017, 2017
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The Arctic and Pacific oceans are connected by the presently ~53 m deep Bering Strait. During the last glacial period when the sea level was lower than today, the Bering Strait was exposed. Humans and animals could then migrate between Asia and North America across the formed land bridge. From analyses of sediment cores and geophysical mapping data from Herald Canyon north of the Bering Strait, we show that the land bridge was flooded about 11 000 years ago.
Johan Nilsson, Martin Jakobsson, Chris Borstad, Nina Kirchner, Göran Björk, Raymond T. Pierrehumbert, and Christian Stranne
The Cryosphere, 11, 1745–1765, https://doi.org/10.5194/tc-11-1745-2017, https://doi.org/10.5194/tc-11-1745-2017, 2017
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Recent data suggest that a 1 km thick ice shelf extended over the glacial Arctic Ocean during MIS 6, about 140 000 years ago. Here, we theoretically analyse the development and equilibrium features of such an ice shelf. The ice shelf was effectively dammed by the Fram Strait and the mean ice-shelf thickness was controlled primarily by the horizontally integrated mass balance. Our results can aid in resolving some outstanding questions of the state of the glacial Arctic Ocean.
Clint M. Miller, Gerald R. Dickens, Martin Jakobsson, Carina Johansson, Andrey Koshurnikov, Matt O'Regan, Francesco Muschitiello, Christian Stranne, and Carl-Magnus Mörth
Biogeosciences, 14, 2929–2953, https://doi.org/10.5194/bg-14-2929-2017, https://doi.org/10.5194/bg-14-2929-2017, 2017
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Continental slopes north of the East Siberian Sea are assumed to hold large amounts of methane. We present pore water chemistry from the 2014 SWERUS-C3 expedition. These are among the first results generated from this vast climatically sensitive region, and they imply that abundant methane, including gas hydrates, do not characterize the East Siberian Sea slope or rise. This contradicts previous modeling and discussions, which due to the lack of data are almost entirely based assumption.
Ira Leifer, Denis Chernykh, Natalia Shakhova, and Igor Semiletov
The Cryosphere, 11, 1333–1350, https://doi.org/10.5194/tc-11-1333-2017, https://doi.org/10.5194/tc-11-1333-2017, 2017
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Vast Arctic methane deposits may alter global climate and require remote sensing (RS) to map. Sonar has great promise, but quantitative inversion based on theory is challenged by multiple bubble acoustical scattering in plumes. We demonstrate use of a real-world in situ bubble plume calibration using a bubble model to correct for differences in the calibration and seep plumes. Spatial seep sonar maps were then used to improve understanding of subsurface geologic controls.
Célia J. Sapart, Natalia Shakhova, Igor Semiletov, Joachim Jansen, Sönke Szidat, Denis Kosmach, Oleg Dudarev, Carina van der Veen, Matthias Egger, Valentine Sergienko, Anatoly Salyuk, Vladimir Tumskoy, Jean-Louis Tison, and Thomas Röckmann
Biogeosciences, 14, 2283–2292, https://doi.org/10.5194/bg-14-2283-2017, https://doi.org/10.5194/bg-14-2283-2017, 2017
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The Arctic Ocean, especially the Siberian shelves, overlays large areas of subsea permafrost that is degrading. We show that methane with a biogenic origin is emitted from this permafrost. At locations where bubble plumes have been observed, methane can escape oxidation in the surface sediment and rapidly migrate through the very shallow water column of this region to escape to the atmosphere, generating a positive radiative feedback.
Leif G. Anderson, Göran Björk, Ola Holby, Sara Jutterström, Carl Magnus Mörth, Matt O'Regan, Christof Pearce, Igor Semiletov, Christian Stranne, Tim Stöven, Toste Tanhua, Adam Ulfsbo, and Martin Jakobsson
Ocean Sci., 13, 349–363, https://doi.org/10.5194/os-13-349-2017, https://doi.org/10.5194/os-13-349-2017, 2017
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We use data collected in 2014 to show that the outflow of nutrient-rich water occurs much further to the west than has been reported in the past. We suggest that this is due to much less summer sea-ice coverage in the northwestern East Siberian Sea than in the past decades. Further, our data support a more complicated flow pattern in the region where the Mendeleev Ridge reaches the shelf compared to the general cyclonic circulation within the individual basins as suggested historically.
Christof Pearce, Aron Varhelyi, Stefan Wastegård, Francesco Muschitiello, Natalia Barrientos, Matt O'Regan, Thomas M. Cronin, Laura Gemery, Igor Semiletov, Jan Backman, and Martin Jakobsson
Clim. Past, 13, 303–316, https://doi.org/10.5194/cp-13-303-2017, https://doi.org/10.5194/cp-13-303-2017, 2017
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The eruption of the Alaskan Aniakchak volcano of 3.6 thousand years ago was one of the largest Holocene eruptions worldwide. The resulting ash is found in several Alaskan sites and as far as Newfoundland and Greenland. In this study, we found ash from the Aniakchak eruption in a marine sediment core from the western Chukchi Sea in the Arctic Ocean. Combined with radiocarbon dates on mollusks, the volcanic age marker is used to calculate the marine radiocarbon reservoir age at that time.
Leif G. Anderson, Jörgen Ek, Ylva Ericson, Christoph Humborg, Igor Semiletov, Marcus Sundbom, and Adam Ulfsbo
Biogeosciences, 14, 1811–1823, https://doi.org/10.5194/bg-14-1811-2017, https://doi.org/10.5194/bg-14-1811-2017, 2017
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Waters with very high pCO2, nutrients and low oxygen concentrations were observed along the continental margin of the East Siberian Sea and well out into the deep Makarov and Canada basins during the SWERUS-C3 expedition in 2014. This water had a low saturation state with respect to calcium carbonate, down to less than 0.8 for calcite and 0.5 for aragonite, and is traced in historic data to the Canada Basin and in the waters flowing out of the Arctic Ocean in the western Fram Strait.
Erik Gustafsson, Christoph Humborg, Göran Björk, Christian Stranne, Leif G. Anderson, Marc C. Geibel, Carl-Magnus Mörth, Marcus Sundbom, Igor P. Semiletov, Brett F. Thornton, and Bo G. Gustafsson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-115, https://doi.org/10.5194/bg-2017-115, 2017
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In this study we quantify key carbon cycling processes on the East Siberian Arctic Shelf. A specific aim is to determine the pathways of terrestrial organic carbon (OC) supplied by rivers and coastline erosion – and particularly to what extent degradation of terrestrial OC contributes to air-sea CO2 exchange. We estimate that the shelf is a weak CO2 sink, although this sink is considerably reduced mainly by degradation of eroded OC and to a lesser extent by degradation of riverine OC.
Joan A. Salvadó, Tommaso Tesi, Marcus Sundbom, Emma Karlsson, Martin Kruså, Igor P. Semiletov, Elena Panova, and Örjan Gustafsson
Biogeosciences, 13, 6121–6138, https://doi.org/10.5194/bg-13-6121-2016, https://doi.org/10.5194/bg-13-6121-2016, 2016
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Fluvial discharge and coastal erosion of the permafrost-dominated East Siberian Arctic delivers large quantities of terrigenous organic carbon (Terr-OC) to marine waters. We assessed its fate and composition in different marine pools with a suite of biomarkers. The dissolved organic carbon is transporting off-shelf “young” and fresh vascular plant material, while sedimentary and near-bottom particulate organic carbon preferentially carries old organic carbon released from thawing permafrost.
Robert B. Sparkes, Ayça Doğrul Selver, Örjan Gustafsson, Igor P. Semiletov, Negar Haghipour, Lukas Wacker, Timothy I. Eglinton, Helen M. Talbot, and Bart E. van Dongen
The Cryosphere, 10, 2485–2500, https://doi.org/10.5194/tc-10-2485-2016, https://doi.org/10.5194/tc-10-2485-2016, 2016
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The permafrost in eastern Siberia contains large amounts of carbon frozen in soils and sediments. Continuing global warming is thawing the permafrost and releasing carbon to the Arctic Ocean. We used pyrolysis-GCMS, a chemical fingerprinting technique, to study the types of carbon being deposited on the continental shelf. We found large amounts of permafrost-sourced carbon being deposited up to 200 km offshore.
Lisa Bröder, Tommaso Tesi, Joan A. Salvadó, Igor P. Semiletov, Oleg V. Dudarev, and Örjan Gustafsson
Biogeosciences, 13, 5003–5019, https://doi.org/10.5194/bg-13-5003-2016, https://doi.org/10.5194/bg-13-5003-2016, 2016
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Thawing permafrost may release large amounts of terrestrial organic carbon (TerrOC) to the Arctic Ocean. We assessed its fate in the marine environment with a suite of biomarkers. Across the Laptev Sea their concentrations in surface sediments decreased significantly and showed a trend to qualitatively more degraded TerrOC with increasing water depth. We infer that the degree of degradation of TerrOC is a function of the time spent under oxic conditions during protracted cross-shelf transport.
Juliane Bischoff, Robert B. Sparkes, Ayça Doğrul Selver, Robert G. M. Spencer, Örjan Gustafsson, Igor P. Semiletov, Oleg V. Dudarev, Dirk Wagner, Elizaveta Rivkina, Bart E. van Dongen, and Helen M. Talbot
Biogeosciences, 13, 4899–4914, https://doi.org/10.5194/bg-13-4899-2016, https://doi.org/10.5194/bg-13-4899-2016, 2016
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The Arctic contains a large pool of carbon that is vulnerable to warming and can be released by rivers and coastal erosion. We study microbial lipids (BHPs) in permafrost and shelf sediments to trace the source, transport and fate of this carbon. BHPs in permafrost deposits are released to the shelf by rivers and coastal erosion, in contrast to other microbial lipids (GDGTs) that are transported by rivers. Several further analyses are needed to understand the complex East Siberian Shelf system.
Evan J. Gowan, Paul Tregoning, Anthony Purcell, James Lea, Oscar J. Fransner, Riko Noormets, and J. A. Dowdeswell
Geosci. Model Dev., 9, 1673–1682, https://doi.org/10.5194/gmd-9-1673-2016, https://doi.org/10.5194/gmd-9-1673-2016, 2016
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We present a program that can create paleo-ice sheet reconstructions, using an assumed basal shear stress, margin location and basal topography as input. This allows for the quick determination of relatively realistic past ice sheet configurations without reliance on highly uncertain factors such as climate and ice dynamics. This is ideal for modelling Earth deformation due to the loading of ice sheets. The subsequent ice sheet configurations can be used as an input for climate modelling.
Valeria Luciani, Gerald R. Dickens, Jan Backman, Eliana Fornaciari, Luca Giusberti, Claudia Agnini, and Roberta D'Onofrio
Clim. Past, 12, 981–1007, https://doi.org/10.5194/cp-12-981-2016, https://doi.org/10.5194/cp-12-981-2016, 2016
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The symbiont-bearing planktic foraminiferal genera Morozovella and Acarinina were among the most important calcifiers of the early Paleogene tropical and subtropical oceans. However, a remarkable and permanent switch in the relative abundance of these genera happened in the early Eocene. We show that this switch occurred at low-latitude sites near the start of the Early Eocene Climatic Optimum (EECO), a multi-million-year interval when Earth surface temperatures reached their Cenozoic maximum.
Claudia Agnini, David J. A. Spofforth, Gerald R. Dickens, Domenico Rio, Heiko Pälike, Jan Backman, Giovanni Muttoni, and Edoardo Dallanave
Clim. Past, 12, 883–909, https://doi.org/10.5194/cp-12-883-2016, https://doi.org/10.5194/cp-12-883-2016, 2016
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In this paper we present records of stable C and O isotopes, CaCO3 content, and changes in calcareous nannofossil assemblages in a upper Paleocene-lower Eocene rocks now exposed in northeast Italy. Modifications of nannoplankton assemblages and carbon isotopes are strictly linked one to each other and always display the same ranking and spacing. The integration of this two data sets represents a significative improvement in our capacity to correlate different sections at a very high resolution.
X. Feng, Ö. Gustafsson, R. M. Holmes, J. E. Vonk, B. E. van Dongen, I. P. Semiletov, O. V. Dudarev, M. B. Yunker, R. W. Macdonald, D. B. Montluçon, and T. I. Eglinton
Biogeosciences, 12, 4841–4860, https://doi.org/10.5194/bg-12-4841-2015, https://doi.org/10.5194/bg-12-4841-2015, 2015
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Currently very few studies have examined the distribution and fate of hydrolyzable organic carbon (OC) in Arctic sediments, whose fate remains unclear in the context of climate change. Our study focuses on the source, distribution and fate of hydrolyzable OC as compared with plant wax lipids and lignin phenols in the sedimentary particles of nine Arctic and sub-Arctic rivers. This multi-molecular approach allows for a comprehensive investigation of terrestrial OC transfer via Arctic rivers.
R. B. Sparkes, A. Doğrul Selver, J. Bischoff, H. M. Talbot, Ö. Gustafsson, I. P. Semiletov, O. V. Dudarev, and B. E. van Dongen
Biogeosciences, 12, 3753–3768, https://doi.org/10.5194/bg-12-3753-2015, https://doi.org/10.5194/bg-12-3753-2015, 2015
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Siberian permafrost contains large amounts of organic carbon that may be released by climate warming. We collected and analysed samples from the East Siberian Sea, using GDGT biomarkers to trace the sourcing and deposition of organic carbon across the shelf. We show that branched GDGTs may be used to trace river erosion. Results from modelling show that organic carbon on the shelf is a complex process involving river-derived and coastal-derived material as well as marine carbon production.
J. Ahlkrona, N. Kirchner, and P. Lötstedt
Geosci. Model Dev., 6, 2135–2152, https://doi.org/10.5194/gmd-6-2135-2013, https://doi.org/10.5194/gmd-6-2135-2013, 2013
I. P. Semiletov, N. E. Shakhova, I. I. Pipko, S. P. Pugach, A. N. Charkin, O. V. Dudarev, D. A. Kosmach, and S. Nishino
Biogeosciences, 10, 5977–5996, https://doi.org/10.5194/bg-10-5977-2013, https://doi.org/10.5194/bg-10-5977-2013, 2013
F. O. Nitsche, K. Gohl, R. D. Larter, C.-D. Hillenbrand, G. Kuhn, J. A. Smith, S. Jacobs, J. B. Anderson, and M. Jakobsson
The Cryosphere, 7, 249–262, https://doi.org/10.5194/tc-7-249-2013, https://doi.org/10.5194/tc-7-249-2013, 2013
Related subject area
Subject: Ice Dynamics | Archive: Marine Archives | Timescale: Pleistocene
Ice-proximal sea-ice reconstruction in Powell Basin, Antarctica since the Last Interglacial
Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability
Compilation of Southern Ocean sea-ice records covering the last glacial-interglacial cycle (12–130 ka)
Reconstructing Antarctic winter sea-ice extent during Marine Isotope Stage 5e
Reconstructing the evolution of ice sheets, sea level, and atmospheric CO2 during the past 3.6 million years
Sedimentary record from the Canada Basin, Arctic Ocean: implications for late to middle Pleistocene glacial history
A Late Pleistocene sea level stack
Sea level ~400 000 years ago (MIS 11): analogue for present and future sea-level?
Wee Wei Khoo, Juliane Müller, Oliver Esper, Wenshen Xiao, Christian Stepanek, Paul Gierz, Gerrit Lohmann, Walter Geibert, Jens Hefter, and Gesine Mollenhauer
EGUsphere, https://doi.org/10.5194/egusphere-2024-246, https://doi.org/10.5194/egusphere-2024-246, 2024
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Using a multiproxy approach, we analyzed biomarkers and diatom assemblages from a marine sediment core from the Powell Basin, Weddell Sea. The results reveal the first continuous coastal Antarctic sea ice record since the Last Penultimate Glacial. Our findings contribute valuable insights into past glacial-interglacial sea ice response to a changing climate and enhance our understanding of the ocean-sea ice-ice shelf interactions and dynamics.
Lea Pesjak, Andrew McMinn, Zanna Chase, and Helen Bostock
Clim. Past, 19, 419–437, https://doi.org/10.5194/cp-19-419-2023, https://doi.org/10.5194/cp-19-419-2023, 2023
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This study uses diatom assemblages, biogenic silica and Si/Al data over the last 140 kyr from core TAN1302-44 (64°54' S, 144°32' E) to define glacial-to-interglacial paleoenvironments near Antarctica with respect to sea ice duration and ocean circulation. It has found that the sea ice season increased gradually during the last glacial, reaching a maximum before decreasing at the end of MIS 2. Following this, Circumpolar Deep Water increased relative to other times prior to ice sheet retreat.
Matthew Chadwick, Xavier Crosta, Oliver Esper, Lena Thöle, and Karen E. Kohfeld
Clim. Past, 18, 1815–1829, https://doi.org/10.5194/cp-18-1815-2022, https://doi.org/10.5194/cp-18-1815-2022, 2022
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Algae preserved in seafloor sediments have allowed us to reconstruct how Antarctic sea ice has varied between cold and warm time periods in the last 130 000 years. The patterns and timings of sea-ice increase and decrease vary between different parts of the Southern Ocean. Sea ice is most sensitive to changing climate at the external edges of Southern Ocean gyres (large areas of rotating ocean currents).
Matthew Chadwick, Claire S. Allen, Louise C. Sime, Xavier Crosta, and Claus-Dieter Hillenbrand
Clim. Past, 18, 129–146, https://doi.org/10.5194/cp-18-129-2022, https://doi.org/10.5194/cp-18-129-2022, 2022
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Algae preserved in marine sediments have allowed us to reconstruct how much winter sea ice was present around Antarctica during a past time period (130 000 years ago) when the climate was warmer than today. The patterns of sea-ice increase and decrease vary between different parts of the Southern Ocean. The Pacific sector has a largely stable sea-ice extent, whereas the amount of sea ice in the Atlantic sector is much more variable with bigger decreases and increases than other regions.
Constantijn J. Berends, Bas de Boer, and Roderik S. W. van de Wal
Clim. Past, 17, 361–377, https://doi.org/10.5194/cp-17-361-2021, https://doi.org/10.5194/cp-17-361-2021, 2021
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For the past 2.6 million years, the Earth has experienced glacial cycles, where vast ice sheets periodically grew to cover large parts of North America and Eurasia. In the earlier part of this period, this happened every 40 000 years. This value changed 1.2 million years ago to 100 000 years: the Mid-Pleistocene Transition. We investigate this interesting period using an ice-sheet model, studying the interactions between ice sheets and the global climate.
Linsen Dong, Yanguang Liu, Xuefa Shi, Leonid Polyak, Yuanhui Huang, Xisheng Fang, Jianxing Liu, Jianjun Zou, Kunshan Wang, Fuqiang Sun, and Xuchen Wang
Clim. Past, 13, 511–531, https://doi.org/10.5194/cp-13-511-2017, https://doi.org/10.5194/cp-13-511-2017, 2017
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In this manuscript, we present the results of our study conducted for a sediment core (ARC4-BN05) collected in the Arctic Ocean. Detailed examination of clay and bulk mineralogy along with grain size, content of Ca and Mn, and planktonic foraminiferal numbers in core ARC4–BN05 provides important new information about sedimentary environments and provenance. Based on these proxies, we try to reveal late to middle Pleistocene glacial history.
Rachel M. Spratt and Lorraine E. Lisiecki
Clim. Past, 12, 1079–1092, https://doi.org/10.5194/cp-12-1079-2016, https://doi.org/10.5194/cp-12-1079-2016, 2016
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This study presents an average of seven Late Pleistocene sea level records, which improves the signal-to-noise ratio for estimates of sea level change during glacial cycles of the past 800 000 years.
D. Q. Bowen
Clim. Past, 6, 19–29, https://doi.org/10.5194/cp-6-19-2010, https://doi.org/10.5194/cp-6-19-2010, 2010
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Short summary
Past glacial activity on the East Siberian continental margin is poorly known, partly due to the lack of geomorphological evidence. Here we present geophysical mapping and sediment coring data from the East Siberian shelf and slope revealing the presence of a glacially excavated cross-shelf trough reaching to the continental shelf edge north of the De Long Islands. The data provide direct evidence for extensive glacial activity on the Siberian shelf that predates the Last Glacial Maximum.
Past glacial activity on the East Siberian continental margin is poorly known, partly due to the...
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