Title Changes in glacier dynamics under the influence of proglacial lake formation in Rhonegletscher, Switzerland
Author Tsutaki, S.; Nishimura, D.; Yoshizawa, T.; Sugiyama, S.
Author Affil Tsutaki, S., Hokkaido University, Graduate School of Environmental Science, Sapporo, Japan
Source Annals of Glaciology, 52(58), p.31-36, . Publisher: International Glaciological Society, Cambridge, United Kingdom. ISSN: 0260-3055
Publication Date 2011
Notes In English. 30 refs. GeoRef Acc. No: 310214
Index Terms glacial geology; glacial lakes; glaciers; glacier flow; lakes; thickness; velocity; water pressure; Switzerland; Central Europe; dynamics; elevation; Europe; flotation; glacial features; glacier thinning; ice movement; ice-marginal features; overburden; proglacial lakes; rates; Rhonegletscher
Abstract To investigate the impact of proglacial lake formation on the dynamics and evolution of glaciers, we measured the ice motion of the terminal part of Rhonegletscher, Switzerland, where a lake formed in 2005. In 2009, the flow velocity near the terminus was 20 m a-1. One of the survey stakes tripled its velocity between 2006 and 2007. Since the lake water pressure was consistently close to the ice overburden pressure, it is likely that the high subglacial water pressure enhanced the basal ice motion. The estimated flow velocity due to ice shearing was negligibly small; almost 100% of the horizontal velocity near the terminus was caused by basal sliding. The longitudinal strain rate was large, 0.064 a- 1, indicating that much of the glacier thinning was due to ice dynamics. The region of ice flotation adjacent to the lake expanded between 2008 and 2009 as a result of glacier thinning. Accordingly, a huge uplift of the surface was observed in 2009. It is clear from the vertical ice motion as well as visual observations that the marginal part of the glacier began to float. The ice-thinning rate in the studied area from 2008 to 2009 was 3.4 m a-1, larger than previous estimates.
URL http://www.igsoc.org/annals/v52/58/a58a010.pdf
Publication Type journal article
Record ID 65007349