Weighing the Greenland Ice Sheet using GPS

Presentation given February 2014: Greenland GPS Network (GNET) is being used in combination with other geophysical sensors to examine ice loss in the world’s second largest and most unstable ice sheet. Crustal uplift manifests delayed viscoelastic rebound due to the loss of ice since the Last Glacial Maximum, a phenomenon known as Postglacial Rebound, but also (and mainly) instantaneous elastic uplift in response to present day ice loss. GNET’s measurements give considerable insight into the phenomenology of ice loss in Greenland, including the roles of atmospheric and ocean forcing.

GPS is used to observe crustal motion and deformation in order to study a variety of geodynamical processes, including present-day mountain building processes, fault behavior and earthquakes, water vapor dynamics, sea level change and climate change. The main field areas are the Central and Southern Andes, Greenland and Antarctica. Work has been funded by a variety of US government agencies, including National Science Foundation, and research into the active foreland fold and thrust belts of the Andes has also been supported by the oil industry. (Much of his recent work in Bolivia focuses on the the Subandes, the most rapidly deforming fold and thrust belt in the western hemisphere).  Research into climate change has also been supported by computer time grants from Amazon Web Services. In 2010 the author led the US geodetic response to the 2010 (magnitude 8.8) Maule earthquake in Chile.