ALE’s Union Glacier Camp is one of several hubs from which POLENET field teams deploy and service GPS and seismic stations across Antarctica. For several seasons, ALE has provided flight and landing support for Twin Otter and C-130 Hercules aircraft operating on skis, as well as meals, accommodation and a heated office tent with power for POLENET flight crews and field staff based at Union Glacier.
POLENET (the Polar Earth Observing Network) is a global network dedicated to observing the polar regions in a changing world. The Antarctic-POLENET project (ANET) aims to carry out GPS and seismic studies to advance our understanding of geodynamic processes and their influence on the West Antarctic Ice Sheet. GPS stations record how the bedrock is moving in response to changes in ice mass, and seismic stations record data that provides information about the Earth’s interior properties, giving us a more complete understanding of how the Earth is responding to changes in the ice sheets.
The integrated geodetic and geophysical data will allow testing of key hypotheses about the history and dynamics of the West Antarctic Ice Sheet (WAIS) and interactions with the solid Earth beneath. Both the viscoelastic response of the solid earth, constraining mass change since the Last Glacial Maximum, and the elastic response, resulting from mass change within the last few years/decades, can be modeled from continuous GPS measurements together with earth properties derived from the seismic data. These proxy records for ice mass change will allow better estimates of the contribution of the Antarctica ice sheets to global sea level change.
GPS and seismic stations deployed through ANET are pushing the boundaries of geophysical observations in Antarctica. Stations span the entire length of the Transantarctic Mountains, as well as the interior of West Antarctica. Advances in power, communications, and overall system design have enabled improved data retrieval, more efficient site monitoring, and year round operation, even in the extreme Antarctic environment.
2014 POLENET Field Season
The 2014-15 POLENET/ANET field season consisted of servicing existing GPS/seismic stations, installation of three new GPS stations in collaboration with the Italian program, and deployment of a ‘mini-array’ of seismic sensors on the ice sheet in West Antarctica. The team, based at ALE’s Union Glacier camp, serviced existing stations via Twin Otter and a nearby station by vehicle. A second team based at the United States Antarctic Program’s WAIS Divide field camp visited stations in the Amundsen Embayment and Marie Byrd Land sectors for maintenance/data retrieval. In addition a snowmobile traverse, originating from and returning to the WAIS Divide Camp, deployed an array of 10 seismographs.
McMurdo Station was the hub for servicing existing stations using Twin Otter and helicopter flight support. Coordinated work with the Italian Antarctic program (PNRA) installed 3 GPS systems at existing GPS monuments in northern Victoria Land, using Italian aircraft, and working with Italian team members.