This project constructs POLENET a network of GPS and seismic stations in West Antarctica to understand how the mass of the West Antarctic ice sheet (WAIS) changes with time. The information is ultimately used to predict sea level rise accompanying global warming and interpret climate change records. The GPS (global positioning system) stations measure vertical and horizontal movements of bedrock, while the seismic stations characterize physical properties of the ice/rock interface, lithosphere, and mantle. Combined with satellite data, this project offers a more complete picture of the ice sheet's current state, its likely change in the near future, and its overall size during the last glacial maximum. This data will also be used to infer sub-ice sheet geology and the terrestrial heat flux, critical inputs to models of glacier movement. As well, this project improves tomographic models of the earth's deep interior and core through its location in the Earth's poorly instrumented southern hemisphere.
Abstract
This project constructs POLENET a network of GPS and seismic stations in West Antarctica to understand how the mass of the West Antarctic ice sheet (WAIS) changes with time. The information is ultimately used to predict sea level rise accompanying global warming and interpret climate change records. The GPS (global positioning system) stations measure vertical and horizontal movements of bedrock, while the seismic stations characterize physical properties of the ice/rock interface, lithosphere, and mantle. Combined with satellite data, this project offers a more complete picture of the ice sheet's current state, its likely change in the near future, and its overall size during the last glacial maximum. This data will also be used to infer sub-ice sheet geology and the terrestrial heat flux, critical inputs to models of glacier movement. As well, this project improves tomographic models of the earth's deep interior and core through its location in the Earth's poorly instrumented southern hemisphere.
Broader impacts of this project are varied. The work is relevant to society for improving our understanding of the impacts of global warming on sea level rise. It also supports education at the postdoctoral, graduate, and undergraduate levels, and outreach to groups underrepresented in the sciences. As an International Polar Year contribution, this project establishes a legacy of infrastructure for polar measurements. It also involves an international collaboration of twenty four countries. For more information see IPY Project #185 at IPY.org. NSF is supporting a complementary Arctic POLENET array being constructed in Greenland under NSF Award #0632320.
Broader impacts of this project are varied. The work is relevant to society for improving our understanding of the impacts of global warming on sea level rise. It also supports education at the postdoctoral, graduate, and undergraduate levels, and outreach to groups underrepresented in the sciences. As an International Polar Year contribution, this project establishes a legacy of infrastructure for polar measurements. It also involves an international collaboration of twenty four countries. For more information see IPY Project #185 at IPY.org. NSF is supporting a complementary Arctic POLENET array being constructed in Greenland under NSF Award #0632320.
The project has resulted in the successful installation of a combined Global Positioning System and seismometer network in Antarctica over an area the size of the United States east of the Mississippi River. Previously there were only a few 'campaign style' sites over this huge and inaccessible area that had to be visited every 3-4 years to obtain data, and even fewer continuously recording stations close to the US McMurdo base at the head of the Ross Sea. The Principal Investigator used his knowledge of interior West Antarctica, gained from several decades of geological research there, to help find suitable locations for the instruments, and to make sure these sites were located in the several distinct crustal blocks that make up this part of the continent. The data are now coming in continuously from across this vast area and starting to be used in refining models of the ice sheet, which will be used to ascertain the change in mass of the ice sheet and hence its contribution to global sea level change. The Principal Investigator is now being able to use his knowledge of Antarctic geology and geologic history to help interpret these data. For example, he has already been able to help interpretation of the directions of fast travel of shear waves in the Eath's mantle in terms of the tectonic history of West Antarctica. Previously there was very limited knowledge of the deep crustal structure of West Antarctica.
