Despite the now accepted importance of post-seismic deformation processes during the earthquake cycle, much debate persists about what mechanisms are responsible for the transient deformation, where the deformation occurs, and what the relevant constitutive parameters of the candidate processes are. The occurrence of the Mw 7.9 November 3, 2002 Denali Alaska earthquake has created the opportunity to collect the surface deformation measurements needed to make significant improvements in our knowledge of the dominant deformation mechanisms in the Earth's lithosphere and the rheological parameters of the fault zone and surrounding crust and upper mantle. The large moment of the Denali earthquake, the precise pre-earthquake deformation field, and the immediate field response make this the most promising target to address post-seismic deformation problems since modern space-geodetic methods became available.
This grant supports the upgrade, expansion, and continued operation and maintenance of an existing post-seismic GPS network proximal to the epicenter of the Mw 7.9 November 3, 2002 Denali Alaska Earthquake over a three-year period. Within two weeks of the mainshock, UNAVCO engineers, with NSF support, installed 10 continuous GPS (CGPS) sites near the fault. These sites form the core of a planned 16-station network. The first 10 sites were installed quickly and without power generation or telemetry, in order to get the sites in before extreme winter conditions made work impossible. This funding will allow for upgrade of these existing sites with robust enclosures and solar plus wind power. An additional 6 new CGPS sites will also be established as part of the post-seismic GPS response network. A related Geophysics grant will support geodynamic modeling of the data (EAR-0310410) and all GPS data will be available to the broader scientific community through the UNAVCO GPS data archive. ***