Switching of a paleo-ice stream in northwest Svalbard.

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

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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 ∼2.8–2.6 Ma). A switch in ice stream flow direction to the present-day Kongsfjorden cross-shelf trough took place during a glaciation at ∼1.5 Ma or probably later during an intensive major glaciation phase known as the ‘Mid-Pleistocene Revolution’ starting at ∼1.0 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.
Highlights

► Reflection seismic data reveal two glacial fans at northwest Svalbard margin. ► The fans are result of ice stream activities during Pliocene–Pleistocene glaciations. ► Based on seismic and bathymetric data we find the flow directions of the ice streams. ► We find a switch in ice stream flow direction. ► The switch resulted as the ice sheet became thick and overcame a topographic barrier.

Document Type: Article
Additional Information: Correction: QUATERNARY SCIENCE REVIEWS, 67 207-207; 10.1016/j.quascirev.2013.01.027 MAY 1 2013 WOS:000317871600014
Keywords: Geodynamics; Polar Research; Svalbard; Ice stream; Cross-shelf trough; High-resolution two-dimensional reflection seismic data; Swath-bathymetric data
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1016/j.quascirev.2011.03.013
ISSN: 0277-3791
Projects: Future Ocean
Date Deposited: 24 Feb 2011 09:28
Last Modified: 23 Sep 2019 19:44
URI: http://oceanrep.geomar.de/id/eprint/11542

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