This grant supports continued group purchases of synthetic aperture radar (SAR) imagery from the European Space Agency (ESA) by the Western North America Interferometric SAR (WinSAR) consortium. The U.S. currently has no civilian SAR satellite capability. Since FY 2000, EAR has supported the WinSAR consortium to allow for group purchase of SAR data and to make those data available to WinSAR consortium members through an archival system. Currently there are 25 WinSAR member organizations. WinSAR now maintains over 2000 SAR scenes through archives at Scripps Institution of Oceanography (SIO), Caltech, and Stanford. This support will increase the WinSAR holdings. Individual SAR scenes from the ESA ERS-1/2 and Envisat satellites will be purchased either: 1) directly from ESA - requires that a science proposal submitted to ESA be accepted; or 2) through ESA sanctioned re-sellers of the data (e.g, Eurimage or Spotimage). SAR imagery available through the WinSAR archive has been used for interferometric analysis to provide for spatially continuous images of crustal deformation patterns that are a natural complement to discrete GPS measurements. InSAR imagery has been used by WinSAR consortium member scientists to gain new insight into strain accumulation and release surrounding active faults in western North America (e.g., the San Andreas transform fault system) and for focused studies of co-seismic and post-seismic deformation patterns surrounding the epicenters of large earthquakes (e.g., 1999 Hector Mine Mw 7.2 and 1992 Landers Mw 7.3). InSAR imagery has also provided insight into the dynamics of volcanic systems and land surface subsidence related to petroleum and ground water extraction. ***
