HR: 0800h
AN: G51C-0849    [Abstracts]
TI: InSAR and the Hector Mine Earthquake: Crustal Deformation v Atmospheric Anomaly
AU: * Calzia, J
EM: jcalzia@usgs.gov
AF: U.S. Geological Survey, e45 Middlefield Rd, Menlo Park, CA 94087
AB: A series of SAR interferograms of the southwestern Mojave Desert record the apparent development and collapse of a topographic anomaly near the epicenter of the 16 Oct 1999 Mw7.1 Hector Mine Earthquake. Interferograms generated from Feb 1999 to June 2000 ERS data, using GAMMA software, record the development of an elliptical uplift, centered about 20 km north-northeast of the epicenter. The uplift covers approximately 2700 km2 and a regional amplitude of 2.8 cm; peak amplitude is nearly 7 cm. Although NOAA records indicate no rain fall in the area of the anomaly for October 1999, the close correlation between topography and interference fringes suggests atmospheric stratification between the highest peak and valley floor. Reprocessing the SAR data, using DIAPASON software, resulted in inversion of the anomaly from uplift to depression. This inversion suggests that the topographic anomaly is not caused by crustal deformation, but is a near-surface atmospheric anomaly caused by local transient conditions such as dust or smoke. Although InSAR offers a powerful new tool for earthquake prediction, this study confirms the impact that minor atmosphere contaminants can have on the interpretation of SAR data.
DE: 0321 Cloud/radiation interaction
DE: 0399 General or miscellaneous
SC: Geodesy [G]
MN: Fall Meeting 2005