scholarly journals Comparing Glacial‐Geological Evidence and Model Simulations of Ice Sheet Change since the Last Glacial Period in the Amundsen Sea Sector of Antarctica

2021 ◽  
Author(s):  
J. S. Johnson ◽  
D. Pollard ◽  
P. L. Whitehouse ◽  
S. J. Roberts ◽  
D. H. Rood ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Glacial Period ◽  
Amundsen Sea ◽  
Last Glacial Period ◽  
Geological Evidence ◽  
Model Simulations ◽  
Last Glacial ◽  
The Last Glacial

scholarly journals Oceanic forcing of the Eurasian Ice Sheet on millennial time scales during the Last Glacial Period

2018 ◽  
Author(s):  
Jorge Alvarez-Solas ◽  
Rubén Banderas ◽  
Alexander Robinson ◽  
Marisa Montoya
Keyword(s):  
Time Scales ◽  
North Atlantic ◽  
Climate Changes ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. The last glacial period (LGP; ca.110–10 ka BP) was marked by the existence of two types of abrupt climatic changes, Dansgaard-Oeschger (DO) and Heinrich (H) events. Although the mechanisms behind these are not fully understood, it is generally accepted that the presence of ice sheets played an important role in their occurrence. While an important effort has been made to investigate the dynamics and evolution of the Laurentide Ice Sheet (LIS) during this period, the Eurasian Ice Sheet (EIS) has not received much attention, in particular from a modeling perspective. However, meltwater discharge from this and other ice sheets surrounding the Nordic Seas is often implied as a potential cause of ocean instabilities that lead to glacial abrupt climate changes. Thus, a better understanding of its variations during the LGP is important to understand its role in glacial abrupt climate changes. Here we investigate the response of the EIS to millennial-scale climate variability during the LGP. We use a hybrid, three-dimensional, thermomechanical ice-sheet model that includes ice shelves and ice streams. The model is forced offline through a novel perturbative approach that includes the effect of both atmospheric and oceanic variations and provides a more realistic treatment of millennial-scale climatic variability than conventional methods. Our results show that the EIS responds with enhanced ice discharge in phase with interstadial warming in the North Atlantic when forced with surface ocean temperatures. Conversely, when subsurface ocean temperatures are used, enhanced ice discharge occurs both during stadials and at the beginning of the interstadials. Separating the atmospheric and oceanic effects demonstrates the major role of the ocean in controlling the dynamics of the EIS on millennial time scales. While the atmospheric forcing alone is only able to produce modest iceberg discharges, warming of the ocean leads to higher rates of iceberg discharges as a result of relatively strong basal melting at the margins of the ice sheet. Together with previous work, our results provide a consistent explanation for the response of the LIS and the EIS to glacial abrupt climate changes, and highlight the need for stronger constraints on the local North Atlantic behavior in order to improve our understanding of the ice sheet's glacial dynamics.

scholarly journals Łódź Region and its Northern Vicinity under Vistulian Glaciation Conditions

2014 ◽  
Vol 33 (3) ◽  
pp. 155-163 ◽  
Author(s):  
Małgorzata Roman ◽  
Danuta Dzieduszyńska ◽  
Joanna Petera-Zganiacz
Keyword(s):  
Ice Sheet ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Space And Time ◽  
Different Types ◽  
Geomorphological Map ◽  
The Last Glacial

Abstract An overview of palaeogeographical findings of the last glacial period (MIS 5d-MIS 2) has been given for the Łódź region. Processes which influenced the area outside of ice-sheet margin are presented with respect to space and time, as predominantly driven by different types of periglacial environment. Attention was paid to leading accumulative and erosional processes and resulting landforms, still well-pronounced in the landscape. Recently, the picture of the area discussed, during the Vistulian was completed and identified was the mechanism of the LGM ice-sheet advance onto the Płock lobe. Borderline location of the Łódź region offers comprehensive research on the time and processes and determines its significance on the geomorphological map of Poland.

The presence of polynyas in the Weddell Sea during the Last Glacial Period with implications for the reconstruction of sea-ice limits and ice sheet history

2010 ◽  
Vol 296 (3-4) ◽  
pp. 287-298 ◽  
Author(s):  
James A. Smith ◽  
Claus-Dieter Hillenbrand ◽  
Carol J. Pudsey ◽  
Claire S. Allen ◽  
Alastair G.C. Graham
Keyword(s):  
Sea Ice ◽  
Ice Sheet ◽  
Weddell Sea ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Last Glacial

scholarly journals Convincing evidence for rapid ice sheet growth during the last glacial period

PAGES news ◽  
2008 ◽  
Vol 16 (1) ◽  
pp. 15-16 ◽  
Author(s):  
Mark Siddall ◽  
EJ Rohling ◽  
HW Arz
Keyword(s):  
Ice Sheet ◽  
Convincing Evidence ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Last Glacial

scholarly journals Provenance changes between recent and glacial-time sediments in the Amundsen Sea embayment, West Antarctica: clay mineral assemblage evidence

2011 ◽  
Vol 23 (5) ◽  
pp. 471-486 ◽  
Author(s):  
Werner Ehrmann ◽  
Claus-Dieter Hillenbrand ◽  
James A. Smith ◽  
Alastair G.C. Graham ◽  
Gerhard Kuhn ◽  
...  
Keyword(s):  
Clay Mineral ◽  
Sediment Provenance ◽  
Glacial Period ◽  
High Concentration ◽  
Amundsen Sea ◽  
Last Glacial Period ◽  
Transport Pathways ◽  
Last Glacial ◽  
Catchment Areas ◽  
The Last Glacial

AbstractThe Amundsen Sea embayment is a probable site for the initiation of a future collapse of the West Antarctic Ice Sheet. This paper contributes to a better understanding of the transport pathways of subglacial sediments into this embayment at present and during the last glacial period. It discusses the clay mineral composition of sediment samples taken from the seafloor surface and marine cores in order to decipher spatial and temporal changes in the sediment provenance. The most striking feature in the present-day clay mineral distribution is the high concentration of kaolinite, which is mainly supplied by the Thwaites Glacier system and indicates the presence of hitherto unknown kaolinite-bearing sedimentary strata in the hinterland, probably in the Byrd Subglacial Basin. The main illite input is via the Pine Island Glacier. Smectite originates from the erosion of volcanic rocks in Ellsworth Land and western Marie Byrd Land. The clay mineral assemblages in diamictons deposited during the last glacial period are distinctly different from those in corresponding surface sediments. This relationship indicates that glacial sediment sources were different from modern ones, which could reflect changes in the catchment areas of the glaciers and ice streams.

scholarly journals West Antarctic ice sheet change since the Last Glacial Period

Eos ◽  
2007 ◽  
Vol 88 (17) ◽  
pp. 189-190 ◽  
Author(s):  
Tara Deen ◽  
Claus-Dieter Hillenbrand ◽  
Joanne Johnson ◽  
Rob Larter ◽  
Roy Livermore ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
Last Glacial ◽  
West Antarctic ◽  
The Last Glacial
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