Observations of interannual and spatial variability in rift propagation in the Amery Ice Shelf, Antarctica, 2002-14

TitleObservations of interannual and spatial variability in rift propagation in the Amery Ice Shelf, Antarctica, 2002-14
Publication TypeJournal Article
Year of Publication2015
AuthorsWalker C.C, Bassis J.N, Fricker H.A, Czerwinski R.J
JournalJournal of Glaciology
Volume61
Pagination243-252
Date Published2015/07
Type of ArticleArticle
ISBN Number0022-1430
Accession NumberWOS:000355778000005
KeywordsAntarctic glaciology; deformation; east antarctica; ice shelves; iceberg calving; seismicity; stability
Abstract

Iceberg calving and basal melting are the two primary mass loss processes from the Antarctic ice sheet, accounting for approximately equal amounts of mass loss. Basal melting under ice shelves has been increasingly well constrained in recent work, but changes in iceberg calving rates remain poorly quantified. Here we examine the processes that precede iceberg calving, and focus on initiation and propagation of ice-shelf rifts. Using satellite imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multi-angle Imaging Spectroradiometer (MISR), we monitored five active rifts on the Amery Ice Shelf, Antarctica, from 2002 to 2014. We found a strong seasonal component: propagation rates were highest during (austral) summer and nearly zero during winter. We found substantial variability in summer propagation rates, but found no evidence that the variability was correlated with large-scale environmental drivers, such as atmospheric temperature, winds or sea-ice concentration. We did find a positive correlation between large propagation events and the arrival of tsunamis in the region. The variability appears to be related to visible structural boundaries within the ice shelf, e.g. suture zones or crevasse fields. This suggests that a complete understanding of rift propagation and iceberg calving needs to consider local heterogeneities within an ice shelf.

DOI10.3189/2015JoG14J151
Short TitleJ. Glaciol.
Student Publication: 
No
Research Topics: