High-resolution geophysical observations of the Yermak Plateau and northern Svalbard margin: implications for ice-sheet grounding and deep-keeled icebergs

High-resolution geophysical evidence on the seafloor morphology and acoustic stratigraphy of the Yermak Plateau and northern Svalbard margin between 79�200 and 81�300N and 5� and 22�E is presented. Geophysical datasets are derived from swath bathymetry and sub-bottom acoustic profiling and are combi...

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Bibliographic Details
Published in:Quaternary Science Reviews
Main Authors: Dowdeswell, J. A., Jakobsson, M., Hogan, K. A., O'Regan, Matthew, Backman, J., Evans, J., Hell, B., Lowemark, L., Marcussen, C., Noormets, R., Cofaigh, C. O., Sellen, E., Solvsten, M.
Format: Article in Journal/Newspaper
Language:unknown
Published: Elsevier 2010
Subjects:
QE Geology
Arctic
Svalbard
Yermak Plateau
Arctic Basin
Ice Sheet
Ice Shelf
Iceberg*
Svalbard margin
Yermak plateau
Online Access:https://orca.cardiff.ac.uk/id/eprint/7542/
https://doi.org/10.1016/j.quascirev.2010.06.002
Description
Summary:High-resolution geophysical evidence on the seafloor morphology and acoustic stratigraphy of the Yermak Plateau and northern Svalbard margin between 79�200 and 81�300N and 5� and 22�E is presented. Geophysical datasets are derived from swath bathymetry and sub-bottom acoustic profiling and are combined with existing cores to derive chronological control. Seafloor landforms, in the form of ice-produced lineations, iceberg ploughmarks of various dimensions (including features over 80 m deep and down to about 1000 m), and a moat indicating strong currents are found. The shallow stratigraphy of the Yermak Plateau shows three acoustic units: the first with well-developed stratification produced by hemipelagic sedimentation, often draped over a strong and undulating internal reflector; a second with an undulating upper surface and little acoustic penetration, indicative of the action of ice; a third unit of an acoustically transparent facies, resulting from debris flows. Core chronology suggests a MIS 6 age for the undulating seafloor above about 580 m. There are several possible explanations, including: (a) the flow of a major grounded ice sheet across the plateau crest from Svalbard (least likely given the consolidation state of the underlying sediments); (b) the more transient encroachment of relatively thin ice from Svalbard; or (c) the drift across the plateau of an ice-shelf remnant or megaberg from the Arctic Basin. The latter is our favoured explanation given the evidence currently at our disposal.

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