@article {6236, title = {The De Long Trough: A Newly Discovered Glacial Trough on the East Siberian Continental Margin}, volume = {13,9}, year = {2017}, month = {September 28}, pages = {1269-1284}, publisher = {Copernicus Publications}, abstract = {

Ice sheets extending over parts of the East Siberian continental shelf have been proposed for the last glacial period and during the larger Pleistocene glaciations. The sparse data available over this sector of the Arctic Ocean have left the timing, extent and even existence of these ice sheets largely unresolved. Here we present new geophysical mapping and sediment coring data from the East Siberian shelf and slope collected during the 2014 SWERUS-C3 expedition (SWERUS-C3: Swedish \– Russian \– US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions). The multibeam bathymetry and chirp sub-bottom profiles reveal a set of glacial landforms that include grounding zone formations along the outer continental shelf, seaward of which lies a \>65m thick sequence of glacio-genic debris flows. The glacial landforms are interpreted to lie at the seaward
end of a glacial trough \– the first to be reported on the East Siberian margin, here referred to as the De Long Trough because of its location due north of the De Long Islands. Stratigraphy and dating of sediment cores show that a drape of acoustically laminated sediments covering the glacial deposits is older than 50 cal kyr BP. This provides direct evidence for extensive glacial activity on the Siberian shelf that predates the Last Glacial Maximum and most likely occurred during the Saalian (Marine Isotope Stage (MIS) 6).

}, doi = {doi:10.5194/cp-2017-56, 2017}, url = {https://www.clim-past.net/13/1269/2017/cp-13-1269-2017.pdf}, author = {O{\textquoteright}Regan, M A and Backman, Jan and Barrientos, Natalia and Cronin, Tomas and Laura Gemery and Kirchner, N. and Larry A Mayer and Johan Nilsson and Noormets, R. and Pearce, Christof and Semiltov, I. and Christian Stranne and Martin Jakobsson} } @article {6244, title = {The Deglacial to Holocene Paleoceanography of Bering Strait: Results From the SWERUS-C3 Program}, year = {2017}, month = {December 11-15}, pages = {New Orleans, LA}, abstract = {

The climate-carbon-cryosphere (C3) interactions in the East Siberian Arctic Ocean and related ocean, river and land areas of the Arctic have been the focus for the SWERUS-C3 Program (Swedish \– Russian \– US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions). This multi-investigator, multi-disciplinary program was carried out on a two-leg 90-day long expedition in 2014 with Swedish icebreaker Oden. One component of the expedition consisted of geophysical mapping and coring of Herald Canyon, located on the Chukchi Sea shelf north of the Bering Strait in the western Arctic Ocean. Herald Canyon is strategically placed to capture the history of the Pacific-Arctic Ocean connection and related changes in Arctic Ocean paleoceanography. Here we present a summary of key results from analyses of the marine geophysical mapping data and cores collected from Herald Canyon on the shelf and slope that proved to be particularly well suited for paleoceanographic reconstruction. For example, we provide a new age constraint of 11 cal ka BP on sediments from the uppermost slope for the initial flooding of the Bering Land Bridge and reestablishment of the Pacific-Arctic Ocean connection following the last glaciation. This age corresponds to meltwater pulse 1b (MWP1b) known as a post-Younger Dryas warming in many sea level and paleoclimate records. In addition, high late Holocene sedimentation rates that range between about 100 and 300 cm kyr-1, in Herald Canyon permitted paleoceanographic reconstructions of ocean circulation and sea ice cover at centennial scales throughout the late Holocene. Evidence suggests varying influence from inflowing Pacific water into the western Arctic Ocean including some evidence for quasi-cyclic variability in several paleoceanographic parameters, e.g. micropaleontological assemblages, isotope geochemistry and sediment physical properties.

}, url = {https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/214305}, author = {Martin Jakobsson and Anderson, L and Backman, Jan and Barrientos, Natalia and Bjork, G and Helen K. Coxall and Cronin, Tomas and de Boer, A. and Laura Gemery and Kevin Jerram and Johansson, Carina and Kirchner, N. and Larry A Mayer and M{\"o}rth, C-M. and Johan Nilsson and Noormets, R. and O{\textquoteright}Regan, M A and Pearce, Christof and Semiltov, I. and Christian Stranne} } @article {6237, title = {Post-Glacial Flooding of the Bering Land Bridge Dated to 11 cal ka BP Based on New Geophysical and Sediment records}, volume = {13}, year = {2017}, month = {August 1}, pages = {991-1005}, publisher = {Copernicus Publications}, abstract = {

The Bering Strait connects the Arctic and Pacific oceans and separates the North American and Asian landmasses. The presently shallow ( 53 m) strait was exposed during the sea level lowstand of the last glacial period, which permitted human migration across a land bridge today referred to as the Bering Land Bridge. Proxy studies (stable isotope composition of foraminifera, whale migration into the Arctic Ocean, mollusc and insect fossils and paleobotanical data) have suggested a range of ages for the Bering Strait reopening, mainly falling within the Younger Dryas stadial (12.9\–11.7 cal ka BP). Here we provide new information on the deglacial and post-glacial evolution of the Arctic\–Pacific connection through the Bering Strait based on analyses of geological and geophysical data from Herald Canyon, located north of the Bering Strait on the Chukchi Sea shelf region in the western Arctic Ocean. Our results suggest an initial opening at about 11 cal ka BP in the earliest Holocene, which is later than in several previous studies. Our key evidence is based on a well-dated core from Herald Canyon, in which a shift from a near-shore environment to a Pacific-influenced open marine setting at around 11 cal ka BP is observed. The shift corresponds to meltwater pulse 1b (MWP1b) and is interpreted to signify relatively rapid breaching of the Bering Strait and the submergence of the large Bering Land Bridge. Although the precise rates of sea level rise cannot be quantified, our new results suggest that the late deglacial sea level rise was rapid and occurred after the end of the Younger Dryas stadial.

}, doi = {doi.org/10.5194/cp-13-991-2017}, url = {https://www.clim-past.net/13/991/2017/cp-13-991-2017.pdf}, author = {Martin Jakobsson and Pearce, Christof and Cronin, Tomas and Backman, Jan and Anderson, Louise and Barrientos, Natalia and Bjork, G and Helen K. Coxall and de Boer, A. and Larry A Mayer and M{\"o}rth, C-M. and Johan Nilsson and Rattray, J.E. and Christian Stranne and Semiltov, I. and O{\textquoteright}Regan, M A} } @article {5814, title = {Evidence for an Ice Shelf Covering the Central Arctic Ocean During the Penultimate Glaciation}, volume = {7}, year = {2016}, month = {January 18}, publisher = {Macmillan Publishers Ltd.}, abstract = {

The hypothesis of a km-thick ice shelf covering the entire Arctic Ocean during peak glacial conditions was proposed nearly half a century ago. Floating ice shelves preserve few direct traces after their disappearance, making reconstructions difficult. Seafloor imprints of ice shelves should, however, exist where ice grounded along their flow paths. Here we present new evidence of ice-shelf groundings on bathymetric highs in the central Arctic Ocean, resurrecting the concept of an ice shelf extending over the entire central Arctic Ocean during at least one previous ice age. New and previously mapped glacial landforms together reveal flow of a spatially coherent, in some regions \>1-km thick, central Arctic Ocean ice shelf dated to marine isotope stage 6 (~140\ ka). Bathymetric highs were likely critical in the ice-shelf development by acting as pinning points where stabilizing ice rises formed, thereby providing sufficient back stress to allow ice shelf thickening.

}, keywords = {Arctic Ocean, glaciation, ice shelf}, doi = {doi:10.1038/ncomms10365}, url = {http://www.nature.com/ncomms/2016/160118/ncomms10365/full/ncomms10365.html}, author = {Martin Jakobsson and Johan Nilsson and Anderson, L and Backman, Jan and Bjork, G and Cronin, Tomas and Kirchner, N. and Koshurnikov, Andrey and Larry A Mayer and Noormets, R. and O{\textquoteright}Regan, M A and Christian Stranne and Ananiev, R. and Barrientos, Natalia and Chernykh, D. and Helen K. Coxall and Bjorn Eriksson and Floden, Tom and Laura Gemery and Gustafson, Orjan and Kevin Jerram and Johansson, Carina and Khortov, Alexey and Mohammad, R. and Semiltov, I.} } @article {5706, title = {On the Existence of an East-Siberian-Chukchi Ice Sheet: New Insights from the SWERUS-C3 Expedition 2014}, year = {2015}, month = {December 14-18}, address = {San Francisco, CA}, abstract = {

The glacial history of the vast Siberian continental shelf of the Laptev and East Siberian Seas is poorly known. Most of this shelf area is shallower than 120 m implying that it was exposed land during the Last Glacial Maximum (LGM) as well as during older major Quaternary glaciations. The regional glacial and deglacial history of marine transgression has greatly influenced marine conditions of today\’s Arctic Ocean continental shelves. For example, the present extent of submarine permafrost on the shallow continental shelves is tightly linked to the glacial history, because the submarine permafrost was formed during cold conditions when sea level was low enough for the shelves to be subaerially exposed. Conversely, one explanation for lack of submarine permafrost on some shelf areas is the presence of past ice sheets. Ice sheets extending over parts of the Eastern Siberian continental shelf have been proposed in literature during LGM as well as during older Quaternary glacial periods. However, the sparsely available data from the outer continental shelf and adjacent slope of the Eastern Siberian Arctic Ocean has left the glacial history in this part largely unresolved. Here we present new geophysical mapping and sediment coring data from the shallow East Siberian shelf and adjacent slope collected during the 2014 SWERUS-C3 expedition (SWERUS-C3: Swedish \– Russian \– US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions) with Swedish icebreaker Oden. The mapping, using multibeam sonar, chirp sub-bottom profiler, and electro magnetics, in combination with new sediment cores provide information on past glacial activities, sea-level history and permafrost extent on the Eastern Siberian Arctic Ocean. Combining the new SWERUS-C3 data with previous results from this region raises the question whether an East Siberian-Chukchi ice sheet existed during LGM and/or during older glacial periods.\ 

}, keywords = {chukchi, ice sheet, swerus-c3}, url = {http://fallmeeting.agu.org/2015/}, author = {Martin Jakobsson and O{\textquoteright}Regan, M A and Kirchner, N. and Ananiev, R. and Bachman, Jan and Barrientos, Natalia and Chernykh, D. and Helen K. Coxall and Cronin, Tomas and Koshurnikov, Andrey and Lobkovsky, Leopold and Larry A Mayer and Noormets, R. and Muschitiello, Francesco and Johan Nilsson and Pearce, Christof and Semiltov, I. and Christian Stranne} } @article {5389, title = {Arctic Ocean Glacial History}, volume = {92}, year = {2014}, pages = {42-67}, author = {Martin Jakobsson and Andreassen, K. and Bjarndottir, L.R. and Dove, D. and Dowdeswell, J and England, J.H. and Funder, S. and Hogan, K. and Ingolfsson, O. and Jennings, A. and Larson, N.K. and Kirchner, N. and Landvik, J.Y. and Larry A Mayer and Mikkelsen, N. and Moller, P and Niessen, F. and Johan Nilsson and O{\textquoteright}Regan, M A and Polyak, Leonid and Norgaard-Pedersen, N. and Stein, R.} } @article {, title = {An Arctic Ice Shelf During MIS 6 Constrained by New Geophysical and Geological Data}, volume = {29}, number = {25}, year = {2010}, pages = {3505-3517}, publisher = {Wiley}, keywords = {Other}, author = {Martin Jakobsson and Johan Nilsson and O{\textquoteright}Regan, M A and Backman, Jan and Lowemark, L and Dowdewell, J and Larry A Mayer and Polyak, Leonid and Colleoni, F and Anderson, L and Bjork, G and Darby, D and Eriksson, J and Hanslik, D and Hell, B and Marcussen, C and Sellen, E and Wallin, A} } @article {, title = {The Early Miocene Onset of a Ventilated Circulation Regime in the Arctic Ocean}, volume = {447}, year = {2007}, pages = {986-990}, publisher = {Nature Publishing Group}, keywords = {Other}, author = {Martin Jakobsson and Backman, Jan and Rudels, J and Nycander, J and Frank, M and Larry A Mayer and Jokat, W and Sangiorgi, F and O{\textquoteright}Regan, M A and Brinkhuis, H and King, J W and Moran, K} }