Multibeam bathymetric and sediment profiler evidence for ice grounding on the Chukchi Borderland, Arctic Ocean

Authors

Martin Jakobsson, Stockholm UniversityFollow
James V. Gardner, University of New Hampshire, DurhamFollow
Peter R. Vogt, US Naval Research LaboratoryFollow
Larry A. Mayer, University of New HampshireFollow
Andy Armstrong, University of New Hampshire, DurhamFollow
Jan Backman, Stockholm UniversityFollow
Rick Brennan, University of New Hampshire, Durham
Brian R. Calder, University of New Hampshire, DurhamFollow
John K. Hall, Geological Survey of IsraelFollow
Barbara J. Kraft, University of New Hampshire, Durham

Abstract

Multibeam bathymetry and 3.5-kHz sub-bottom profiler data collected from the US icebreaker Healy in 2003 provide convincing evidence for grounded ice on the Chukchi Borderland off the northern Alaskan margin, Arctic Ocean. The data show parallel, glacially induced seafloor scours, or grooves, and intervening ridges that reach widths of 1000 m (rim to rim) and as much as 40 m relief. Following previous authors, we refer to these features as “megascale glacial lineations (MSGLs).” Additional support for ice grounding is apparent from stratigraphic unconformities, interpreted to have been caused by ice-induced erosion. Most likely, the observed sea-floor features represent evidence for massive ice-shelf grounding. The general ESE/WNW direction of the MSGLs, together with sediment, evidently bulldozed off the Chukchi Plateau, that is mapped on the western (Siberian) side of the plateau, suggests ice flow from the Canada Basin side of Chukchi Borderland. Two separate generations of glacially derived MSGLs are identified on the Chukchi Borderland from the Healy geophysical data. The deepest and oldest extensive MSGLs appear to be draped by sediments less than 5 m thick, whereas no sediment drape can be distinguished within the resolution of the sub-bottom profiles on the younger generation.

Department

Center for Coastal and Ocean Mapping

Publication Date

3-2005

Volume

63

Journal Title

Quaternary Research

Pages

150-160

Publisher Place

New York, NY

Publisher

Elsevier

Digital Object Identifier (DOI)

10.1016/j.yqres.2004.12.004

Document Type

Journal Article

Recommended Citation

Martin Jakobsson, James V. Gardner, Peter R. Vogt, Larry A. Mayer, Andrew Armstrong, Jan Backman, Rick Brennan, Brian Calder, John K. Hall, Barbara Kraft, Multibeam bathymetric and sediment profiler evidence for ice grounding on the Chukchi Borderland, Arctic Ocean, Quaternary Research, Volume 63, Issue 2, March 2005, Pages 150-160, ISSN 0033-5894, http://dx.doi.org/10.1016/j.yqres.2004.12.004.