An Arctic ice shelf during MIS 6 constrained by new geophysical and geological data
The hypothesis of floating ice shelves covering the Arctic Ocean during glacial periods was developed in the 1970s. In its most extreme form, this theory involved a 1000 m thick continuous ice shelf covering the Arctic Ocean during Quaternary glacial maxima including the Last Glacial Maximum (LGM)....
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ftuninhampshire:oai:scholars.unh.edu:ccom-1082 2023-05-15T14:38:45+02:00 An Arctic ice shelf during MIS 6 constrained by new geophysical and geological data Jakobsson, Martin Nilsson, Johan O'Regan, Matthew Backman, Jan Lowemark, Ludvig Dowdeswell, Julian A. Mayer, Larry A. Polyak, Leonid Colleoni, Florence Anderson, Leif G. Bjork, Goran Darby, Dennis Eriksson, Bjorn Hanslik, Daniela Hell, Benjamin Marcussen, Christian Sellen, Emma Wallin, Asa 2010-12-01T08:00:00Z https://scholars.unh.edu/ccom/83 http://www.sciencedirect.com/science/article/pii/S0277379110000934 unknown University of New Hampshire Scholars' Repository https://scholars.unh.edu/ccom/83 http://www.sciencedirect.com/science/article/pii/S0277379110000934 Center for Coastal and Ocean Mapping Oceanography and Atmospheric Sciences and Meteorology text 2010 ftuninhampshire 2023-01-30T21:31:51Z The hypothesis of floating ice shelves covering the Arctic Ocean during glacial periods was developed in the 1970s. In its most extreme form, this theory involved a 1000 m thick continuous ice shelf covering the Arctic Ocean during Quaternary glacial maxima including the Last Glacial Maximum (LGM). While recent observations clearly demonstrate deep ice grounding events in the central Arctic Ocean, the ice shelf hypothesis has been difficult to evaluate due to a lack of information from key areas with severe sea ice conditions. Here we present new data from previously inaccessible, unmapped areas that constrain the spatial extent and timing of marine ice sheets during past glacials. These data include multibeam swath bathymetry and subbottom profiles portraying glaciogenic features on the Chukchi Borderland, southern Lomonosov Ridge north of Greenland, Morris Jesup Rise, and Yermak Plateau. Sediment cores from the mapped areas provide age constraints on the glaciogenic features. Combining these new geophysical and geological data with earlier results suggests that an especially extensive marine ice sheet complex, including an ice shelf, existed in the Amerasian Arctic Ocean during Marine Isotope Stage (MIS) 6. From a conceptual oceanographic model we speculate that the cold halocline of the Polar Surface Water may have extended to deeper water depths during MIS 6 inhibiting the warm Atlantic water from reaching the Amerasian Arctic Ocean and, thus, creating favorable conditions for ice shelf development. The hypothesis of a continuous 1000 m thick ice shelf is rejected because our mapping results show that several areas in the central Arctic Ocean substantially shallower than 1000 m water depth are free from glacial influence on the seafloor. Text Arctic Arctic Ocean Chukchi Greenland Ice Sheet Ice Shelf Ice Shelves Lomonosov Ridge Sea ice Yermak plateau University of New Hampshire: Scholars Repository Arctic Arctic Ocean Chukchi Borderland ENVELOPE(-165.000,-165.000,77.000,77.000) Greenland Morris Jesup Rise ENVELOPE(-20.000,-20.000,83.750,83.750) Yermak Plateau ENVELOPE(5.000,5.000,81.250,81.250) |
institution |
Open Polar |
collection |
University of New Hampshire: Scholars Repository |
op_collection_id |
ftuninhampshire |
language |
unknown |
topic |
Oceanography and Atmospheric Sciences and Meteorology |
spellingShingle |
Oceanography and Atmospheric Sciences and Meteorology Jakobsson, Martin Nilsson, Johan O'Regan, Matthew Backman, Jan Lowemark, Ludvig Dowdeswell, Julian A. Mayer, Larry A. Polyak, Leonid Colleoni, Florence Anderson, Leif G. Bjork, Goran Darby, Dennis Eriksson, Bjorn Hanslik, Daniela Hell, Benjamin Marcussen, Christian Sellen, Emma Wallin, Asa An Arctic ice shelf during MIS 6 constrained by new geophysical and geological data |
topic_facet |
Oceanography and Atmospheric Sciences and Meteorology |
description |
The hypothesis of floating ice shelves covering the Arctic Ocean during glacial periods was developed in the 1970s. In its most extreme form, this theory involved a 1000 m thick continuous ice shelf covering the Arctic Ocean during Quaternary glacial maxima including the Last Glacial Maximum (LGM). While recent observations clearly demonstrate deep ice grounding events in the central Arctic Ocean, the ice shelf hypothesis has been difficult to evaluate due to a lack of information from key areas with severe sea ice conditions. Here we present new data from previously inaccessible, unmapped areas that constrain the spatial extent and timing of marine ice sheets during past glacials. These data include multibeam swath bathymetry and subbottom profiles portraying glaciogenic features on the Chukchi Borderland, southern Lomonosov Ridge north of Greenland, Morris Jesup Rise, and Yermak Plateau. Sediment cores from the mapped areas provide age constraints on the glaciogenic features. Combining these new geophysical and geological data with earlier results suggests that an especially extensive marine ice sheet complex, including an ice shelf, existed in the Amerasian Arctic Ocean during Marine Isotope Stage (MIS) 6. From a conceptual oceanographic model we speculate that the cold halocline of the Polar Surface Water may have extended to deeper water depths during MIS 6 inhibiting the warm Atlantic water from reaching the Amerasian Arctic Ocean and, thus, creating favorable conditions for ice shelf development. The hypothesis of a continuous 1000 m thick ice shelf is rejected because our mapping results show that several areas in the central Arctic Ocean substantially shallower than 1000 m water depth are free from glacial influence on the seafloor. |
format |
Text |
author |
Jakobsson, Martin Nilsson, Johan O'Regan, Matthew Backman, Jan Lowemark, Ludvig Dowdeswell, Julian A. Mayer, Larry A. Polyak, Leonid Colleoni, Florence Anderson, Leif G. Bjork, Goran Darby, Dennis Eriksson, Bjorn Hanslik, Daniela Hell, Benjamin Marcussen, Christian Sellen, Emma Wallin, Asa |
author_facet |
Jakobsson, Martin Nilsson, Johan O'Regan, Matthew Backman, Jan Lowemark, Ludvig Dowdeswell, Julian A. Mayer, Larry A. Polyak, Leonid Colleoni, Florence Anderson, Leif G. Bjork, Goran Darby, Dennis Eriksson, Bjorn Hanslik, Daniela Hell, Benjamin Marcussen, Christian Sellen, Emma Wallin, Asa |
author_sort |
Jakobsson, Martin |
title |
An Arctic ice shelf during MIS 6 constrained by new geophysical and geological data |
title_short |
An Arctic ice shelf during MIS 6 constrained by new geophysical and geological data |
title_full |
An Arctic ice shelf during MIS 6 constrained by new geophysical and geological data |
title_fullStr |
An Arctic ice shelf during MIS 6 constrained by new geophysical and geological data |
title_full_unstemmed |
An Arctic ice shelf during MIS 6 constrained by new geophysical and geological data |
title_sort |
arctic ice shelf during mis 6 constrained by new geophysical and geological data |
publisher |
University of New Hampshire Scholars' Repository |
publishDate |
2010 |
url |
https://scholars.unh.edu/ccom/83 http://www.sciencedirect.com/science/article/pii/S0277379110000934 |
long_lat |
ENVELOPE(-165.000,-165.000,77.000,77.000) ENVELOPE(-20.000,-20.000,83.750,83.750) ENVELOPE(5.000,5.000,81.250,81.250) |
geographic |
Arctic Arctic Ocean Chukchi Borderland Greenland Morris Jesup Rise Yermak Plateau |
geographic_facet |
Arctic Arctic Ocean Chukchi Borderland Greenland Morris Jesup Rise Yermak Plateau |
genre |
Arctic Arctic Ocean Chukchi Greenland Ice Sheet Ice Shelf Ice Shelves Lomonosov Ridge Sea ice Yermak plateau |
genre_facet |
Arctic Arctic Ocean Chukchi Greenland Ice Sheet Ice Shelf Ice Shelves Lomonosov Ridge Sea ice Yermak plateau |
op_source |
Center for Coastal and Ocean Mapping |
op_relation |
https://scholars.unh.edu/ccom/83 http://www.sciencedirect.com/science/article/pii/S0277379110000934 |
_version_ |
1766310781187522560 |