Title Crevasses triggered on Pine Island Glacier, West Antarctica by drilling through an exceptional melt layer
Author Scott, J.B.T.; Smith, A.M.; Bingham, R.G.; Vaughan, D.G.
Author Affil Scott, J.B.T., British Antarctic Survey, Cambridge, United Kingdom
Source Glaciology in the International Polar Year, prefaced by G.H. Gudmundsson. Annals of Glaciology, 51(55), p.65-70, . Publisher: International Glaciological Society, Cambridge, United Kingdom. ISSN: 0260- 3055
Publication Date 2010
Notes In English. 18 refs. CRREL Acc. No: 64004758
Index Terms crevasses; drilling; firn; glacial geology; glaciers; ice; ice mechanics; remote sensing; Antarctica--West Antarctica; Antarctica; ice cores; International Polar Year 2007-08; IPY 2007-08 Research Publications; Pine Island Glacier; satellite methods; West Antarctica
Abstract The basic theory of crevasse formation suggests that crevasses initiate at or near the surface. However, due to variations in stress with depth, it has been suggested that it is possible for crevasses to initiate at depths of 10-30 m. From December 2006 to January 2007, hot-water drilling on Pine Island Glacier, West Antarctica, was found to trigger crevasses. Satellite imagery and field investigations in 2008, including ice cores, radar and GPS, revealed that these formed a new band of arcuate (curvilinear) crevasses around 70 km long and 100 m deep. This new band is located 10 km upstream from the previous limit of the arcuate crevasse zone. The crevasses were triggered on drilling through an exceptional ice layer at 20 m depth. Ice layers within the firn will change both the strength and stress intensity. As the firn changes spatially and temporally (e.g. with the burial of an ice layer), it is possible for the position of crevasse initiation to change whilst the along-stream strain-rate profile remains constant. However, the main cause of an upstream migration of the arcuate crevasse zone on Pine Island Glacier is still likely to be an increase in strain rate.
URL http://www.igsoc.org/annals/v51/55/a55a006.pdf
Publication Type journal article
Record ID 300288