Switching of a paleo-ice stream in northwest Svalbard


Sarkar, Sudipta, Berndt, Christian, Chabert, Anne, Masson, Douglas G., Minshull, Timothy A. and Westbrook, Graham K. (2011) Switching of a paleo-ice stream in northwest Svalbard. Quaternary Science Reviews, 30, (13-14), 1710-1725. (doi:10.1016/j.quascirev.2011.03.013).

Download

[img]
Preview
PDF - Pre print
Download (1995Kb) | Preview

Description/Abstract

Ice streams are the fast-flowing zones of ice sheets that can discharge a large flux of ice. The glaciated western Svalbard margin consists of several cross-shelf troughs which are the former ice stream drainage pathways during the Pliocene–Pleistocene glaciations. From an integrated analysis of high-resolution multibeam swath-bathymetric data and several high-resolution two-dimensional reflection seismic profiles across the western and northwestern Svalbard margin we infer the ice stream flow directions and the deposition centres of glacial debris that the ice streams deposited on the outer margin. Our results show that the northwestern margin of Svalbard experienced a switching of a major ice stream. Based on correlation with the regional seismic stratigraphy as well as the results from ODP 911 on Yermak Plateau and ODP 986 farther south on the western margin of Spitsbergen, off Van Mijenfjord, we find that first a northwestward flowing ice stream developed during initial northern hemispheric cooling (starting not, vert, similar2.8–2.6 Ma). A switch in ice stream flow direction to the present-day Kongsfjorden cross-shelf trough took place during a glaciation at not, vert, similar1.5 Ma or probably later during an intensive major glaciation phase known as the ‘Mid-Pleistocene Revolution’ starting at not, vert, similar1.0 Ma. The seismic and bathymetric data suggest that the switch was abrupt rather than gradual and we attribute it to the reaching of a tipping point when growth of the Svalbard ice sheet had reached a critical thickness and the ice sheet could overcome a topographic barrier.

Item Type: Article
Additional Information: See corrigendum at: http://eprints.soton.ac.uk/353526/
ISSNs: 0277-3791 (print)
Keywords: Svalbard; Ice stream; Cross-shelf trough; High-resolution two-dimensional reflection seismic data; Swath-bathymetric data
Subjects: G Geography. Anthropology. Recreation > GC Oceanography
Q Science > QE Geology
Divisions: Faculty of Natural and Environmental Sciences > Ocean and Earth Science > Geology & Geophysics
National Oceanography Centre (NERC) > Marine Geoscience
ePrint ID: 195589
Date Deposited: 23 Aug 2011 12:28
Last Modified: 21 Jul 2014 11:01
Projects:
Dynamics of gas hydrates in polar marine environments.
Funded by: NERC (NE/D005728/2)
Led by: Timothy Minshull
1 April 2008 to 31 January 2011
URI: http://eprints.soton.ac.uk/id/eprint/195589

Actions (login required)

View Item View Item

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics