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The majority of mass lost from the Antarctic ice sheet takes place at the fringing ice shelves via iceberg calving. Iceberg calving is controlled by the initiation and propagation of large scale rifts (fractures that penetrate through the entire ice shelf thickness), which precede large tabular iceberg detachment and can lead to ice shelf break- up. Our study area is the Amery Ice Shelf, East Antarctica, where we have observed over the past 5 Antarctic summer seasons an active rift system using a network of GPS and seismic stations. Here we report on the analysis of some of the GPS measurements. Strain rates are determined for a network of 11 sites observed over three weeks during the 2004/05 Antarctic summer period. In order to investigate possible changes in rift fracture mechanics, the results are combined with, and compared to, strain rates obtained in the 2002/03 season, when a sparser 6-station network was deployed for 46 days. Analysis of the network using a cumulative sum approach, obtained by differencing a pair of residual baseline time series situated approximately normal and parallel to the rift, is found to be an effective method to detect small baseline length changes.

Item Type:	Conference Extract
Keywords:	Antarctica, Amery Ice Shelf, ice sheet, fringing ice shelves, iceberg calving, rift system, GPS, seismic stations, change, monitoring
Research Division:	Earth Sciences
Research Group:	Geophysics
Research Field:	Geodesy
Objective Division:	Environmental Policy, Climate Change and Natural Hazards
Objective Group:	Adaptation to climate change
Objective Field:	Social impacts of climate change and variability
UTAS Author:	Janssen, V (Dr Volker Janssen)
UTAS Author:	Coleman, R (Professor Richard Coleman)
ID Code:	50707
Year Published:	2007
Deposited By:	Geography and Environmental Studies
Deposited On:	2007-08-01
Last Modified:	2013-01-15
Downloads:	264 View Download Statistics