Articles | Volume 1, issue 1
https://doi.org/10.5194/gchron-1-53-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gchron-1-53-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
18 Nov 2019
Research article |
| 18 Nov 2019
| 18 Nov 2019
Amino acid racemization in Quaternary foraminifera from the Yermak Plateau, Arctic Ocean
Department of Geological Sciences, Stockholm University, 10691
Stockholm, Sweden
Darrell S. Kaufman
School of Earth and Sustainability, Northern Arizona University,
Flagstaff, AZ 86011, USA
Francesco Muschitiello
Department of Geography, University of Cambridge, Cambridge, CB2 3EN, UK
Matthias Forwick
Department of Geosciences, UiT The Arctic University of Norway, 9037 Tromsø, Norway
Jens Matthiessen
Alfred Wegener Institute for Polar and Marine Research, 27570
Bremerhaven, Germany
Jutta Wollenburg
Alfred Wegener Institute for Polar and Marine Research, 27570
Bremerhaven, Germany
Matt O'Regan
Department of Geological Sciences, Stockholm University, 10691
Stockholm, Sweden
Related authors
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Lara F. Pérez, Paul C. Knutz, John R. Hopper, Marit-Solveig Seidenkrantz, Matt O'Regan, and Stephen Jones
Sci. Dril., 33, 33–46, https://doi.org/10.5194/sd-33-33-2024, https://doi.org/10.5194/sd-33-33-2024, 2024
Short summary
Short summary
The Greenland ice sheet is highly sensitive to global warming and a major contributor to sea level rise. In Northeast Greenland, ice–ocean–tectonic interactions are readily observable today, but geological records that illuminate long-term trends are lacking. NorthGreen aims to promote scientific drilling proposals to resolve key scientific questions on past changes in the Northeast Greenland margin that further affected the broader Earth system.
Laura J. Larocca, James M. Lea, Michael P. Erb, Nicholas P. McKay, Megan Phillips, Kara A. Lamantia, and Darrell S. Kaufman
EGUsphere, https://doi.org/10.5194/egusphere-2024-522, https://doi.org/10.5194/egusphere-2024-522, 2024
Short summary
Short summary
Here we present summer snowline altitude (SLA) timeseries for 269 Arctic glaciers. Between 1984 and 2022, SLAs rose ~150 m, equating to a ~127 m shift per 1 °C of summer warming. SLA is most strongly correlated with annual temperature variables, highlighting their dual effect on ablation and accumulation processes. We show that SLAs are rising fastest on low elevation glaciers, and that >50 % of the studied glaciers may be doomed to disappear by 2100 if the mean rate of SLA rise is maintained.
Francesco Muschitiello and Marco Antonio Aquino-Lopez
Clim. Past Discuss., https://doi.org/10.5194/cp-2023-65, https://doi.org/10.5194/cp-2023-65, 2023
Preprint under review for CP
Short summary
Short summary
The first continuously measured transfer function that quantifies the age difference between the Greenland Ice-Core Chronology 2005 (GICC05) and the U-Th timescale is presented. The transfer function was generated using a novel probabilistic algorithm for the synchronization of proxy signals. The results greatly improve the accuracy and precision of previous synchronization estimates and reveal that the annual-layer counting error of GICC05 is less systematic than previously assumed.
Kevin Zoller, Jan Sverre Laberg, Tom Arne Rydningen, Katrine Husum, and Matthias Forwick
Clim. Past, 19, 1321–1343, https://doi.org/10.5194/cp-19-1321-2023, https://doi.org/10.5194/cp-19-1321-2023, 2023
Short summary
Short summary
Marine geologic data from NE Greenland provide new information about the behavior of the Greenland Ice Sheet from the last glacial period to present. Seafloor landforms suggest that a large, fast-flowing ice stream moved south through southern Dove Bugt. This region is believed to have been deglaciated from at least 11.4 ka cal BP. Ice in an adjacent fjord, Bessel Fjord, may have retreated to its modern position by 7.1 ka cal BP, and the ice halted or readvanced multiple times upon deglaciation.
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
Short summary
Short summary
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.
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
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-70, https://doi.org/10.5194/tc-2023-70, 2023
Revised manuscript accepted for TC
Short summary
Short summary
Shape and surface textures of silt-sized sediments are measured to connect marine sediment records with subglacial water flow. We find grain-shape alteration is greatest for glaciers in temperate settings and for which high-energy drainage events are implied, and that the surfaces of silt-sized sediments preserve evidence of glacial transport. Our results suggest grain shape and texture may reveal whether glaciers previously experienced temperate conditions with more abundant meltwater.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Darrell S. Kaufman and Nicholas P. McKay
Clim. Past, 18, 911–917, https://doi.org/10.5194/cp-18-911-2022, https://doi.org/10.5194/cp-18-911-2022, 2022
Short summary
Short summary
Global mean surface temperatures are rising to levels unprecedented in over 100 000 years. This conclusion takes into account both recent global warming and likely future warming, which thereby enables a direct comparison with paleotemperature reconstructions on multi-century timescales.
Lauren J. Davies, Britta J. L. Jensen, and Darrell S. Kaufman
Geochronology, 4, 121–141, https://doi.org/10.5194/gchron-4-121-2022, https://doi.org/10.5194/gchron-4-121-2022, 2022
Short summary
Short summary
Subarctic and Arctic lake sediments provide key data to understand natural climate variability and future climate change. However, they can be difficult to date accurately and of limited use without a robust chronology. We use volcanic ash deposits from the last ~4000 BP to identify anomalously old radiocarbon ages at Cascade Lake, Alaska. A provisional ~15 000-year Bayesian age model is produced for the lake, and a new location for ash from five Late Holocene eruptions is reported.
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
Short summary
Short summary
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.
Francesco Muschitiello
Clim. Past Discuss., https://doi.org/10.5194/cp-2021-116, https://doi.org/10.5194/cp-2021-116, 2021
Preprint withdrawn
Short summary
Short summary
The first continuously measured transfer functions that quantify the age difference between the Greenland Ice-Core Chronology 2005 (GICC05) and the U-Th timescale are presented. The transfer functions were generated using a novel probabilistic algorithm for the synchronization of proxy signals. The results greatly improve the accuracy and precision of previous synchronization estimates and reveal that the annual-layer counting error of GICC05 is less systematic than previously assumed.
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
Short summary
Short summary
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.
Jutta E. Wollenburg, Jelle Bijma, Charlotte Cremer, Ulf Bickmeyer, and Zora Mila Colomba Zittier
Biogeosciences, 18, 3903–3915, https://doi.org/10.5194/bg-18-3903-2021, https://doi.org/10.5194/bg-18-3903-2021, 2021
Short summary
Short summary
Cultured at in situ high-pressure conditions Cibicides and Cibicidoides taxa develop lasting ectoplasmic structures that cannot be retracted or resorbed. An ectoplasmic envelope surrounds their test and may protect the shell, e.g. versus carbonate aggressive bottom water conditions. Ectoplasmic roots likely anchor the specimens in areas of strong bottom water currents, trees enable them to elevate themselves above ground, and twigs stabilize and guide the retractable pseudopodial network.
Douglas P. Steen, Joseph S. Stoner, Jason P. Briner, and Darrell S. Kaufman
Geochronology Discuss., https://doi.org/10.5194/gchron-2021-19, https://doi.org/10.5194/gchron-2021-19, 2021
Publication in GChron not foreseen
Short summary
Short summary
Paleomagnetic data from Cascade Lake (Brooks Range, Alaska) extend the radiometric-based age model of the sedimentary sequence extending back 21 kyr. Correlated ages based on prominent features in paleomagnetic secular variations (PSV) diverge from the radiometric ages in the upper 1.6 m, by up to about 2000 years at around 4 ka. Four late Holocene cryptotephra in this section support the PSV chronology and suggest the influence of hard water or aged organic material.
Cody C. Routson, Darrell S. Kaufman, Nicholas P. McKay, Michael P. Erb, Stéphanie H. Arcusa, Kendrick J. Brown, Matthew E. Kirby, Jeremiah P. Marsicek, R. Scott Anderson, Gonzalo Jiménez-Moreno, Jessica R. Rodysill, Matthew S. Lachniet, Sherilyn C. Fritz, Joseph R. Bennett, Michelle F. Goman, Sarah E. Metcalfe, Jennifer M. Galloway, Gerrit Schoups, David B. Wahl, Jesse L. Morris, Francisca Staines-Urías, Andria Dawson, Bryan N. Shuman, Daniel G. Gavin, Jeffrey S. Munroe, and Brian F. Cumming
Earth Syst. Sci. Data, 13, 1613–1632, https://doi.org/10.5194/essd-13-1613-2021, https://doi.org/10.5194/essd-13-1613-2021, 2021
Short summary
Short summary
We present a curated database of western North American Holocene paleoclimate records, which have been screened on length, resolution, and geochronology. The database gathers paleoclimate time series that reflect temperature, hydroclimate, or circulation features from terrestrial and marine sites, spanning a region from Mexico to Alaska. This publicly accessible collection will facilitate a broad range of paleoclimate inquiry.
Ingrid Leirvik Olsen, Tom Arne Rydningen, Matthias Forwick, Jan Sverre Laberg, and Katrine Husum
The Cryosphere, 14, 4475–4494, https://doi.org/10.5194/tc-14-4475-2020, https://doi.org/10.5194/tc-14-4475-2020, 2020
Short summary
Short summary
We present marine geoscientific data from Store Koldewey Trough, one of the largest glacial troughs offshore NE Greenland, to reconstruct the ice drainage pathways, ice sheet extent and ice stream dynamics of this sector during the last glacial and deglaciation. The complex landform assemblage in the trough reflects a dynamic retreat with several periods of stabilization and readvances, interrupting the deglaciation. Estimates indicate that the ice front locally retreated between 80–400 m/year.
Chris M. Brierley, Anni Zhao, Sandy P. Harrison, Pascale Braconnot, Charles J. R. Williams, David J. R. Thornalley, Xiaoxu Shi, Jean-Yves Peterschmitt, Rumi Ohgaito, Darrell S. Kaufman, Masa Kageyama, Julia C. Hargreaves, Michael P. Erb, Julien Emile-Geay, Roberta D'Agostino, Deepak Chandan, Matthieu Carré, Partrick J. Bartlein, Weipeng Zheng, Zhongshi Zhang, Qiong Zhang, Hu Yang, Evgeny M. Volodin, Robert A. Tomas, Cody Routson, W. Richard Peltier, Bette Otto-Bliesner, Polina A. Morozova, Nicholas P. McKay, Gerrit Lohmann, Allegra N. Legrande, Chuncheng Guo, Jian Cao, Esther Brady, James D. Annan, and Ayako Abe-Ouchi
Clim. Past, 16, 1847–1872, https://doi.org/10.5194/cp-16-1847-2020, https://doi.org/10.5194/cp-16-1847-2020, 2020
Short summary
Short summary
This paper provides an initial exploration and comparison to climate reconstructions of the new climate model simulations of the mid-Holocene (6000 years ago). These use state-of-the-art models developed for CMIP6 and apply the same experimental set-up. The models capture several key aspects of the climate, but some persistent issues remain.
Bronwen L. Konecky, Nicholas P. McKay, Olga V. Churakova (Sidorova), Laia Comas-Bru, Emilie P. Dassié, Kristine L. DeLong, Georgina M. Falster, Matt J. Fischer, Matthew D. Jones, Lukas Jonkers, Darrell S. Kaufman, Guillaume Leduc, Shreyas R. Managave, Belen Martrat, Thomas Opel, Anais J. Orsi, Judson W. Partin, Hussein R. Sayani, Elizabeth K. Thomas, Diane M. Thompson, Jonathan J. Tyler, Nerilie J. Abram, Alyssa R. Atwood, Olivier Cartapanis, Jessica L. Conroy, Mark A. Curran, Sylvia G. Dee, Michael Deininger, Dmitry V. Divine, Zoltán Kern, Trevor J. Porter, Samantha L. Stevenson, Lucien von Gunten, and Iso2k Project Members
Earth Syst. Sci. Data, 12, 2261–2288, https://doi.org/10.5194/essd-12-2261-2020, https://doi.org/10.5194/essd-12-2261-2020, 2020
Jan Erik Arndt, Robert D. Larter, Claus-Dieter Hillenbrand, Simon H. Sørli, Matthias Forwick, James A. Smith, and Lukas Wacker
The Cryosphere, 14, 2115–2135, https://doi.org/10.5194/tc-14-2115-2020, https://doi.org/10.5194/tc-14-2115-2020, 2020
Short summary
Short summary
We interpret landforms on the seabed and investigate sediment cores to improve our understanding of the past ice sheet development in this poorly understood part of Antarctica. Recent crack development of the Brunt ice shelf has raised concerns about its stability and the security of the British research station Halley. We describe ramp-shaped bedforms that likely represent ice shelf grounding and stabilization locations of the past that may reflect an analogue to the process going on now.
Jutta E. Wollenburg, Morten Iversen, Christian Katlein, Thomas Krumpen, Marcel Nicolaus, Giulia Castellani, Ilka Peeken, and Hauke Flores
The Cryosphere, 14, 1795–1808, https://doi.org/10.5194/tc-14-1795-2020, https://doi.org/10.5194/tc-14-1795-2020, 2020
Short summary
Short summary
Based on an observed omnipresence of gypsum crystals, we concluded that their release from melting sea ice is a general feature in the Arctic Ocean. Individual gypsum crystals sank at more than 7000 m d−1, suggesting that they are an important ballast mineral. Previous observations found gypsum inside phytoplankton aggregates at 2000 m depth, supporting gypsum as an important driver for pelagic-benthic coupling in the ice-covered Arctic Ocean.
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
Short summary
Short summary
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.
Paul D. Zander, Sönke Szidat, Darrell S. Kaufman, Maurycy Żarczyński, Anna I. Poraj-Górska, Petra Boltshauser-Kaltenrieder, and Martin Grosjean
Geochronology, 2, 63–79, https://doi.org/10.5194/gchron-2-63-2020, https://doi.org/10.5194/gchron-2-63-2020, 2020
Short summary
Short summary
Recent technological advances allow researchers to obtain radiocarbon ages from smaller samples than previously possible. We investigate the reliability and precision of radiocarbon ages obtained from miniature (11–150 μg C) samples of terrestrial plant fragments taken from sediment cores from Lake Żabińskie, Poland. We further investigate how sampling density (the number of ages per 1000 years) and sample mass (which is related to age precision) influence the performance of age–depth models.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Ellie Broadman, Lorna L. Thurston, Erik Schiefer, Nicholas P. McKay, David Fortin, Jason Geck, Michael G. Loso, Matt Nolan, Stéphanie H. Arcusa, Christopher W. Benson, Rebecca A. Ellerbroek, Michael P. Erb, Cody C. Routson, Charlotte Wiman, A. Jade Wong, and Darrell S. Kaufman
Earth Syst. Sci. Data, 11, 1957–1970, https://doi.org/10.5194/essd-11-1957-2019, https://doi.org/10.5194/essd-11-1957-2019, 2019
Short summary
Short summary
Rapid climate warming is impacting physical processes in Arctic environments. Glacier–fed lakes are influenced by many of these processes, and they are impacted by the changing behavior of weather, glaciers, and rivers. We present data from weather stations, river gauging stations, lake moorings, and more, following 4 years of environmental monitoring in the watershed of Lake Peters, a glacier–fed lake in Arctic Alaska. These data can help us study the changing dynamics of this remote setting.
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
Short summary
Short summary
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.
Chris S. M. Turney, Helen V. McGregor, Pierre Francus, Nerilie Abram, Michael N. Evans, Hugues Goosse, Lucien von Gunten, Darrell Kaufman, Hans Linderholm, Marie-France Loutre, and Raphael Neukom
Clim. Past, 15, 611–615, https://doi.org/10.5194/cp-15-611-2019, https://doi.org/10.5194/cp-15-611-2019, 2019
Short summary
Short summary
This PAGES (Past Global Changes) 2k (climate of the past 2000 years working group) special issue of Climate of the Past brings together the latest understanding of regional change and impacts from PAGES 2k groups across a range of proxies and regions. The special issue has emerged from a need to determine the magnitude and rate of change of regional and global climate beyond the timescales accessible within the observational record.
Richard H. Levy, Gavin B. Dunbar, Marcus J. Vandergoes, Jamie D. Howarth, Tony Kingan, Alex R. Pyne, Grant Brotherston, Michael Clarke, Bob Dagg, Matthew Hill, Evan Kenton, Steve Little, Darcy Mandeno, Chris Moy, Philip Muldoon, Patrick Doyle, Conrad Raines, Peter Rutland, Delia Strong, Marianna Terezow, Leise Cochrane, Remo Cossu, Sean Fitzsimons, Fabio Florindo, Alexander L. Forrest, Andrew R. Gorman, Darrell S. Kaufman, Min Kyung Lee, Xun Li, Pontus Lurcock, Nicholas McKay, Faye Nelson, Jennifer Purdie, Heidi A. Roop, S. Geoffrey Schladow, Abha Sood, Phaedra Upton, Sharon L. Walker, and Gary S. Wilson
Sci. Dril., 24, 41–50, https://doi.org/10.5194/sd-24-41-2018, https://doi.org/10.5194/sd-24-41-2018, 2018
Short summary
Short summary
A new annually resolvable sedimentary record of southern hemisphere climate has been recovered from Lake Ohau, South Island, New Zealand. The Lake Ohau Climate History (LOCH) Project acquired cores from two sites that preserve an 80 m thick sequence of laminated mud that accumulated since the lake formed ~ 17 000 years ago. Cores were recovered using a purpose-built barge and drilling system designed to recover soft sediment from relatively thick sedimentary sequences at water depths up to 100 m.
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
Short summary
Short summary
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.
Bryan N. Shuman, Cody Routson, Nicholas McKay, Sherilyn Fritz, Darrell Kaufman, Matthew E. Kirby, Connor Nolan, Gregory T. Pederson, and Jeannine-Marie St-Jacques
Clim. Past, 14, 665–686, https://doi.org/10.5194/cp-14-665-2018, https://doi.org/10.5194/cp-14-665-2018, 2018
Short summary
Short summary
A synthesis of 93 published records reveals that moisture availability increased over large portions of North America over the past 2000 years, the Common Era (CE). In many records, the second millennium CE tended to be wetter than the first millennium CE. The long-term changes formed the background for annual to multi-decade variations, such as "mega-droughts", and also provide a context for amplified rates of hydrologic change today.
Darrell S. Kaufman and PAGES 2k special-issue editorial team
Clim. Past, 14, 593–600, https://doi.org/10.5194/cp-14-593-2018, https://doi.org/10.5194/cp-14-593-2018, 2018
Short summary
Short summary
We explain the procedure used to attain a high and consistent level of data stewardship across a special issue of the journal Climate of the Past. We discuss the challenges related to (1) determining which data are essential for public archival, (2) using data generated by others, and (3) understanding data citations. We anticipate that open-data sharing in paleo sciences will accelerate as the advantages become more evident and as practices that reduce data loss become the accepted convention.
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
Short summary
Short summary
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.
Matt O'Regan, Jan Backman, Natalia Barrientos, Thomas M. Cronin, Laura Gemery, Nina Kirchner, Larry A. Mayer, Johan Nilsson, Riko Noormets, Christof Pearce, Igor Semiletov, Christian Stranne, and Martin Jakobsson
Clim. Past, 13, 1269–1284, https://doi.org/10.5194/cp-13-1269-2017, https://doi.org/10.5194/cp-13-1269-2017, 2017
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Mélanie Wary, Frédérique Eynaud, Didier Swingedouw, Valérie Masson-Delmotte, Jens Matthiessen, Catherine Kissel, Jena Zumaque, Linda Rossignol, and Jean Jouzel
Clim. Past, 13, 729–739, https://doi.org/10.5194/cp-13-729-2017, https://doi.org/10.5194/cp-13-729-2017, 2017
Short summary
Short summary
The last glacial period was punctuated by abrupt climatic variations, whose cold atmospheric phases have been commonly associated with cold sea-surface temperatures and expansion of sea ice in the North Atlantic and adjacent seas. Here we provide direct evidence of a regional paradoxical see-saw pattern: cold Greenland and North Atlantic phases coincide with warmer sea-surface conditions and shorter seasonal sea-ice cover durations in the Norwegian Sea as compared to warm phases.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
F. J. Davies, H. Renssen, M. Blaschek, and F. Muschitiello
Clim. Past, 11, 571–586, https://doi.org/10.5194/cp-11-571-2015, https://doi.org/10.5194/cp-11-571-2015, 2015
M. Łącka, M. Zajączkowski, M. Forwick, and W. Szczuciński
Clim. Past, 11, 587–603, https://doi.org/10.5194/cp-11-587-2015, https://doi.org/10.5194/cp-11-587-2015, 2015
Short summary
Short summary
Storfjordrenna was deglaciated about 13,950 cal yr BP. During the transition from the sub-glacial to glaciomarine setting, Arctic Waters dominated its hydrography. However, the waters were not uniformly cold and experienced several warmer spells. Atlantic Water began to flow onto the shelves off Svalbard and into Storfjorden during the early Holocene, leading to progressive warming and significant glacial melting. A surface-water cooling and freshening occurred in late Holocene.
H. S. Sundqvist, D. S. Kaufman, N. P. McKay, N. L. Balascio, J. P. Briner, L. C. Cwynar, H. P. Sejrup, H. Seppä, D. A. Subetto, J. T. Andrews, Y. Axford, J. Bakke, H. J. B. Birks, S. J. Brooks, A. de Vernal, A. E. Jennings, F. C. Ljungqvist, K. M. Rühland, C. Saenger, J. P. Smol, and A. E. Viau
Clim. Past, 10, 1605–1631, https://doi.org/10.5194/cp-10-1605-2014, https://doi.org/10.5194/cp-10-1605-2014, 2014
Related subject area
Amino acid racemization
A new method for amino acid geochronology of the bivalve shell Arctica islandica
Amino acid racemization in Neogloboquadrina pachyderma and Cibicidoides wuellerstorfi from the Arctic Ocean and its implications for age models
Martina L. G. Conti, Paul G. Butler, David J. Reynolds, Tamara Trofimova, James D. Scourse, and Kirsty E. H. Penkman
EGUsphere, https://doi.org/10.5194/egusphere-2023-2560, https://doi.org/10.5194/egusphere-2023-2560, 2023
Short summary
Short summary
The mollusc Arctica islandica can survive for hundreds of years and its annual growth captures environmental conditions, so each shell provides a detailed climatic record. Dating is essential for sample selection, but radiocarbon and crossdating are time-consuming and costly. As an alternative, amino acid geochronology was investigated in the three aragonitic layers forming the shells. This study confirms the value of AAG as a method for rangefinder dating Quaternary A. islandica shells.
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
Short summary
Short summary
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.
Cited articles
Alexanderson, H., Backman, J., Cronin, T. M., Funder, S., Ingolfsson, O.,
Jakobsson, M., Landvik, J. Y., Löwemark, L., Mangerud, J., März, C.,
and Möller, P.: An Arctic perspective on dating Mid-Late Pleistocene
environmental history, Quaternary Sci. Rev., 92, 9–31,
https://doi.org/10.1016/j.quascirev.2013.09.023, 2014.
Backman, J., Jakobsson, M., Løvlie, R., Polyak, L., and Febo, L. A.: Is
the central Arctic Ocean a sediment starved basin?, Quaternary Sci. Rev.,
23, 1435–1454, https://doi.org/10.1016/j.quascirev.2003.12.005, 2004.
Backman, J., Jakobsson, M., Frank, M., Sangiorgi, F., Brinkhuis, H.,
Stickley, C., O'Regan, M., Løvlie, R., Pälike, H., Spofforth, D., and
Gattacecca, J.: Age model and core-seismic integration for the Cenozoic
Arctic Coring Expedition sediments from the Lomonosov Ridge,
Paleoceanography, 23, PA1S03, https://https://doi.org/10.1029/2007PA001476, 2008.
Bergsten, H.: Recent benthic foraminifera of a transect from the North Pole
to the Yermak Plateau, eastern central Arctic Ocean, Mar. Geol., 119,
251–267, https://doi.org/10.1016/0025-3227(94)90184-8, 1994.
Carstens, J. and Wefer, G.: Recent distribution of planktonic foraminifera
in the Nansen Basin, Arctic Ocean, Deep Sea Res.Part A, 39, S507–S524,
https://doi.org/10.1016/s0198-0149(06)80018-x, 1992.
Carstens, J., Hebbeln, D., and Wefer, G.: Distribution of planktic
foraminifera at the ice margin in the Arctic (Fram Strait), Mar.
Micropaleontol., 29, 257–269,
https://doi.org/10.1016/s0377-8398(96)00014-x, 1997.
Clark, D.: Magnetic Reversals and Sedimentation Rates in the Arctic Ocean,
GSA Bull., 81, 3129–3134,
https://doi.org/10.1130/0016-7606(1970)81[3129:MRASRI]2.0.CO;2, 1970.
Goodfriend, G. A., Brigham-Grette, J., and Miller, G. H.: Enhanced age
resolution of the marine Quaternary record in the Arctic using aspartic acid
racemization dating of bivalve shells, Quaternary Res., 45, 176–187,
https://doi.org/10.1006/qres.1996.0018, 1996.
Greco, M., Jonkers, L., Kretschmer, K., Bijma, J., and Kucera, M.: Depth habitat of the planktonic foraminifera Neogloboquadrina pachyderma in the northern high latitudes explained by sea-ice and chlorophyll concentrations, Biogeosciences, 16, 3425–3437, https://doi.org/10.5194/bg-16-3425-2019, 2019.
Haake, F. W. and Pflaumann, U. W. E.: Late Pleistocene foraminiferal
stratigraphy on the Vøring Plateau, Norwegian Sea, Boreas, 18,
343–356, https://doi.org/10.1111/j.1502-3885.1989.tb00410.x, 1989.
Hastings, W. K.: Monte Carlo sampling methods using Markov chains and their
applications, Biometrika, 57, 97–109,
https://doi.org/10.1093/biomet/57.1.97, 1970.
Hearty, P. J., O'Leary, M. J., Kaufman, D. S., Page, M. C., and Bright, J.:
Amino acid geochronology of individual foraminifer (Pulleniatina obliquiloculata) tests, north Queensland margin, Australia: a new approach
to correlating and dating Quaternary tropical marine sediment cores,
Paleoceanography, 19, PA4022, https://doi.org/10.1029/2004PA001059, 2004.
Jakobsson, M., Løvlie, R., Arnold, E. M., Backman, J., Polyak, L.,
Knutsen, J. O., and Musatov, E.: Pleistocene stratigraphy and
paleoenvironmental variation from Lomonosov Ridge sediments, central Arctic
Ocean, Global Planet. Change, 31, 1–22,
https://doi.org/10.1016/s0921-8181(01)00110-2, 2001.
Jakobsson, M., Mayer, L., Coakley, B., Dowdeswell, J. A., Forbes, S.,
Fridman, B., Hodnesdal, H., Noormets, R., Pedersen, R., Rebesco, M., and
Schenke, H. W.: The international bathymetric chart of the Arctic Ocean
(IBCAO) version 3.0., Geophys. Res. Lett., 39, L12609,
https://doi.org/10.1029/2012GL052219, 2012.
Jones, E. P.: Circulation in the arctic ocean, Polar Res., 20,
139–146, https://doi.org/10.1111/j.1751-8369.2001.tb00049.x, 2001.
Kaufman, D. S.: Temperature sensitivity of aspartic and glutamic acid
racemization in the foraminifera Pulleniatina, Quaternary Geochronol., 1,
188–207, https://doi.org/10.1016/j.quageo.2006.06.008, 2006.
Kaufman, D. S. and Manley, W. F.: A new procedure for determining DL amino
acid ratios in fossils using reverse phase liquid chromatography, Quaternary
Sci. Rev., 17, 987–1000, https://doi.org/10.1016/s0277-3791(97)00086-3,
1998.
Kaufman, D. S., Polyak, L., Adler, R., Channell, J. E., and Xuan, C.: Dating
late Quaternary planktonic foraminifer Neogloboquadrina pachyderma from the
Arctic Ocean using amino acid racemization, Paleoceanography, 23, PA3224,
https://https://doi.org/10.1029/2008PA001618, 2008.
Kaufman, D. S., Cooper, K., Behl, R., Billups, K., Bright, J., Gardner, K.,
Hearty, P., Jakobsson, M., Mendes, I., O'Leary, M., and Polyak, L.: Amino
acid racemization in mono-specific foraminifera from Quaternary deep-sea
sediments, Quaternary Geochronol., 16, 50–61,
https://doi.org/10.1016/j.quageo.2012.07.006, 2013.
King, K. and Neville, C.: Isoleucine epimerization for dating marine
sediments: importance of analyzing monospecific foraminiferal samples,
Science, 195, 1333–1335,
https://doi.org/10.1126/science.195.4284.1333, 1977.
Kosnik, M. A. and Kaufman, D. S.: Identifying outliers and assessing the
accuracy of amino acid racemization measurements for geochronology: II. Data
screening, Quaternary Geochronol., 3, 328–341,
https://doi.org/10.1016/j.quageo.2008.04.001, 2008.
Kremer, A., Stein, R., Fahl, K., Ji, Z., Yang, Z., Wiers, S., Matthiessen,
J., Forwick, M., Löwemark, L., O'Regan, M., and Chen, J.: Changes in sea
ice cover and ice sheet extent at the Yermak Plateau during the last 160
ka – Reconstructions from biomarker records, Quaternary Sci. Rev., 182,
93–108, https://doi.org/10.1016/j.quascirev.2017.12.016, 2018.
Lisiecki, L. E. and Raymo, M. E.: A Pliocene-Pleistocene stack of 57
globally distributed benthic δ18O records, Paleoceanography, 20,
PA1003, https://doi.org/10.1029/2004PA001071, 2005.
Lougheed, B. C., Metcalfe, B., Ninnemann, U. S., and Wacker, L.: Moving beyond the age-depth model paradigm in deep-sea palaeoclimate archives: dual radiocarbon and stable isotope analysis on single foraminifera, Clim. Past, 14, 515–526, https://doi.org/10.5194/cp-14-515-2018, 2018.
Macko, S. A. and Aksu, A. E.: Amino acid epimerization in planktonic
foraminifera suggests slow sedimentation rates for Alpha Ridge, Arctic
Ocean, Nature, 322, 730–732, https://doi.org/10.1038/322730a0, 1986.
Malinverno, A.: Data report: Monte Carlo correlation of sediment records from core and downhole log measurements at Sites U1337 and U1338 (IODP Expedition 321), edited by: Pälike, H., Lyle, M., Nishi, H., Raffi, I., Gamage, K., Klaus, A., and the Expedition 320/321 Scientists, Proc. IODP, 320/321: Tokyo (Integrated Ocean Drilling Program Management International, Inc.),
https://doi.org/10.2204/iodp.proc.320321.207.2013, 2013.
Martinson, D. G., Pisias, N. G., Hays, J. D., Imbrie, J., Moore, T. C., and
Shackleton, N. J.: Age dating and the orbital theory of the ice ages:
Development of a high-resolution 0 to 300,000-year chronostratigraphy 1,
Quaternary Res., 27, 1–29, https://doi.org/10.1016/0033-5894(87)90046-9,
1987.
Metropolis, N., Rosenbluth, A. W., Rosenbluth, M. N., Teller, A. H., and Teller,
E.: Equation of state calculations by fast computing machines, J. Chem.
Phys., 21, 1087–1092, https://doi.org/10.1063/1.1699114, 1953.
Muschitiello, F.: Deglacial impact of the Scandinavian Ice Sheet on the
North Atlantic climate system (Doctoral dissertation, Department of
Geological Sciences), 2016.
Muschitiello, F., Pausata, F. S., Watson, J. E., Smittenberg, R. H., Salih,
A. A., Brooks, S. J., Whitehouse, N. J., Karlatou-Charalampopoulou, A., and
Wohlfarth, B.: Fennoscandian freshwater control on Greenland hydroclimate
shifts at the onset of the Younger Dryas, Nat. Commun., 6, 8939,
https://doi.org/10.1038/ncomms9939, 2015.
Muschitiello, F., D'Andrea, W. J., Schmittner, A., Heaton, T. J., Balascio,
N. L., DeRoberts, N., Caffee, M. W., Woodruff, T. E., Welten, K. C., Skinner,
L. C., and Simon, M. H.: Deep-water circulation changes lead North Atlantic
climate during deglaciation, Nat. Commun., 10, 1272,
https://doi.org/10.1038/s41467-019-09237-3, 2019.
Okay, N. and Crane, K.: Thermal rejuvenation of the Yermak Plateau, Mar.
Geophys. Res., 15, 243–263, https://doi.org/10.1007/bf01982384, 1993.
O'Regan, M., Moran, K., Backman, J., Jakobsson, M., Sangiorgi, F.,
Brinkhuis, H., Pockalny, R., Skelton, A., Stickley, C., Koç, N., and
Brumsack, H. J.: Mid-Cenozoic tectonic and paleoenvironmental setting of the
central Arctic Ocean, Paleoceanography, 23, PA1S20,
https://doi.org/10.1029/2007PA001559, 2008.
Pados, T. and Spielhagen, R. F.: Species distribution and depth habitat of
recent planktic foraminifera in Fram Strait, Arctic Ocean, Polar Res.,
33, 22483, https://doi.org/10.3402/polar.v33.22483, 2014.
Polyak, L. and Solheim, A.: Late-and postglacial environments in the
northern Barents Sea west of Franz Josef Land, Polar Res., 13, 197–207,
https://doi.org/10.1111/j.1751-8369.1994.tb00449.x, 1994.
Sejrup, H. P., Miller, G. H., Brigham-Grette, J., Løvlie, R., and
Hopkins, D.: Amino acid epimerization implies rapid sedimentation rates in
Arctic Ocean cores, Nature, 310, 772–775,
https://doi.org/10.1038/310772a0, 1984.
Sejrup, H. P. and Haugen, J. E.: Amino acid diagenesis in the marine
bivalve Arctica islandica Linné from northwest European sites: only time
and temperature?, J. Quaternary Sci., 9, 301–309,
https://doi.org/10.1002/jqs.3390090402, 1994.
Shephard, G. E., Wiers, S., Bazhenova, E., Pérez, L. F., Mejía, L.
M., Johansson, C., Jakobsson, M., and O'Regan, M.: A North Pole thermal
anomaly? Evidence from new and existing heat flow measurements from the
central Arctic Ocean, J. Geodyn., 118, 166–181,
https://doi.org/10.1016/j.jog.2018.01.017, 2018.
Ślubowska, M. A., Koç, N., Rasmussen, T. L., and
Klitgaard-Kristensen, D.: Changes in the flow of Atlantic water into the
Arctic Ocean since the last deglaciation: evidence from the northern
Svalbard continental margin, 80 N, Paleoceanography, 20, PA4014,
https://doi.org/10.1029/2005PA001141, 2005.
Stein, R.: The great challenges in Arctic Ocean paleoceanography, IOP
Conf. Ser. Earth Environ. Sci., 14, 012001,
https://doi.org/10.1088/1755-1315/14/1/012001, 2011.
Vihola, M.: Robust adaptive Metropolis algorithm with coerced acceptance
rate, Stat. Comput., 22, 997–1008,
https://doi.org/10.1007/s11222-011-9269-5, 2012.
Wehmiller, J. F.: Interlaboratory comparison of amino acid enantiomeric
ratios in fossil Pleistocene mollusks, Quaternary Res., 22, 109–120,
https://doi.org/10.1016/0033-5894(84)90010-3, 1984.
West, G., Kaufman, D. S., Muschitiello, F., Forwick, M., Matthiessen, J., Wollenburg, J., and O'Regan, M.:
Yermak Plateau, Arctic Ocean 227 ka Foraminifer Amino Acid Racemization Data, NOAA, available at: https://www.ncdc.noaa.gov/paleo-search/study/27812, last access: 15 November 2019.
Wiers, S., Snowball, I., O’Regan, M., and Almqvist, B.: Late Pleistocene Chronology of Sediments from the Yermak
Plateau and Uncertainty in Dating Based on Geomagnetic Excursions, Geochem. Geophys. Geosys., 20, 3289–3310, https://doi.org/10.1029/2018gc007920, 2019.
Wohlfarth, B., Luoto, T. P., Muschitiello, F., Väliranta, M., Björck,
S., Davies, S. M., Kylander, M., Ljung, K., Reimer, P. J., and Smittenberg,
R. H.: Climate and environment in southwest Sweden 15.5–11.3 cal. ka BP,
Boreas, 47, 687–710, https://doi.org/10.1111/bor.12310, 2018.
Wollenburg, J. E. and Mackensen, A.: Living benthic foraminifers from the
central Arctic Ocean: faunal composition, standing stock and diversity, Mar.
Micropaleontol., 34, 153–185,
https://doi.org/10.1016/s0377-8398(98)00007-3, 1998.
Wollenburg, J. E., Kuhnt, W., and Mackensen, A.: Changes in Arctic Ocean
paleoproductivity and hydrography during the last 145 kyr: the benthic
foraminiferal record, Paleoceanogr. Paleocl., 16, 65–77, 2001.
Wollenburg, J. E., Knies, J., and Mackensen, A.: High-resolution
paleoproductivity fluctuations during the past 24 kyr as indicated by
benthic foraminifera in the marginal Arctic Ocean, Palaeogeogr. Palaeocl.,
204, 209–238, https://doi.org/10.1016/s0031-0182(03)00726-0, 2004.
Xuan, C., Channell, J. E., Polyak, L., and Darby, D. A.: Paleomagnetism of
Quaternary sediments from Lomonosov Ridge and Yermak Plateau: implications
for age models in the Arctic Ocean, Quaternary Sci. Rev., 32, 48–63,
https://doi.org/10.1016/j.quascirev.2011.11.015, 2012.
Short summary
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.
We report amino acid racemization analyses of foraminifera from well-dated sediment cores from...
