Research Objectives:
The TAMDEF project is a joint program of the USGS and Ohio State University to measure crustal motion in the Transantarctic Mountains of Southern Victoria Land.
Crustal movement is predicted as a result of variations in the ice volume and loading of the East and West Antarctic Ice Sheets through time. Researchers also suspect that there is active tectonism associated with the Terror Rift, an nearby offshore fault zone. There are also active volcanoes in the region that may also be responsible for a measurable amount of crustal deformation.
The TAMDEF-II (Transantarctic Mountains DEFormation) program will extend this project's GPS time series by repeat surveying of key sites in the existing TAMDEF network. Project researchers are also implementing new strategies to discriminate glacio-isostatic from tectonic motions and thus increase the significance of previous results for modeling ice sheet behavior. The objectives of this program are to:
+ Constrain neotectonic deformation patterns across the frontal fault zone of the Transantarctic Mountains, the active Terror Rift, and the zone of active volcanism on Ross Island, by resurveying original TAMDEF sites;
+ Test models of postglacial rebound by extending the array southward across a significant gradient in predicted vertical motion and across known time points in West Antarctic deglaciation history where ice mass loads, crustal structure and rheological characteristics are relatively well characterized;
+ Assess regional tectonic and rebound-related motion patterns in the antarctic interior by integrating TAMDEF measurements with an Italian GPS array deployed in northern Victoria Land; and
+ Model regional and continental-scale postglacial rebound and neotectonic activity using GPS measurements integrated with independent records of relative sea level, deglacial chronology, ice mass load changes, and tectonic strain patterns.
