Mapping Pleistocene-age shoreline deposits in the seismically-active Salton Trough using thermal infrared multi-spectral scanner (TIMS) data

摘要

The Salton Trough region of southern California is one of the most tectonically active regions in North America. Pleistocene-age shoreline deposits of the ancient Lake Cahuilla have been documented at various locations throughout the Salton Trough and potentially across several active faults. Extensive mapping of the shoreline deposits would allow their use as time-stratigraphic horizons and precise elevational surveying would permit characterization of vertical deformation, and provide information on displacement and slip rates. Imagery from the NASA/JPL airborne Thermal Infrared Multi-spectral Scanner ( TIMS) and field radiometric data were evaluated for their applicability to mapping the Pleistocene-age shoreline deposits. Differences in the textural and minera-logical properties of shoreline deposits relative to the surrounding lacustrine and alluvial sediments were exploited. The results show that when compared with field-derived maps of known shoreline deposits, digitally enhanced TIMS imagery enabled reliable delineation of the shoreline deposits.