TY - JOUR
T1 - Crevasses triggered on Pine Island Glacier, West Antarctica, by drilling through an exceptional melt layer
AU - Scott, Julian B.T.
AU - Smith, Andrew M.
AU - Bingham, Robert G.
AU - Vaughan, David G.
PY - 2010/6/1
Y1 - 2010/6/1
N2 - 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.
AB - 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.
U2 - 10.3189/172756410791392763
DO - 10.3189/172756410791392763
M3 - Article
SN - 0260-3055
VL - 51
SP - 65
EP - 70
JO - Annals of Glaciology
JF - Annals of Glaciology
IS - 55
ER -