Title Tides and the flow of Rutford Ice Stream, West Antarctica
Author Gudmundsson, G.H.
Author Affil Gudmundsson, G.H., British Antarctic Survey, Cambridge, United Kingdom
Source Journal of Geophysical Research, 112( F4), F04007. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0148-0227
Publication Date Dec. 24, 2007
Notes In English. Includes appendices. 41 refs. GeoRef Acc. No: 284628. CRREL Acc. No: 62004923
Index Terms friction; glacial geology; glacier flow; models; sediments; stresses; tides; velocity; Antarctica--West Antarctica; Antarctica; Burgers model; clastic sediments; coastal environment; cycles; Global Positioning System; ice movement; ice streams; ocean circulation; Rutford Ice Stream; stress; till; West Antarctica
Abstract Surface speeds of Rutford Ice Stream, West Antarctica, are known to vary by around 10-20% (depending on location) with a fortnightly periodicity corresponding to a spring-neap tidal cycle. The reasons for these periodic variations in flow are unclear. Here the possible role of tidal stress transmission upstream of the grounding line in affecting rates of basal motion is investigated. It is found that nonlinear rheological effects within the till, when coupled with transmission of tidal stresses within the ice that are linearly related to tidal amplitude, can give rise to the type of periodic oscillations in flow observed. This nonlinear interaction between tidal forcing and till deformation increases the mean ice flux across the grounding line by a few percent above what might be expected in the absence of tidal forcing. (mod. journ. abst.)
URL http://hdl.handle.net/10.1029/2006JF000731
Publication Type journal article
Record ID 84114