Detection of bedrock topography beneath a thin cover of alluvium using thermal remote sensing

Modeling of the annual heat flow within a thin alluvium veneer on a granitic bedrock substrate in desert environments, such as found in the southwestern United States, predicts that at certain times of the year the depth to bedrock has a measurable effect on the surface temperature if the alluvium cover is less than 2 m thick. Changes in the thickness of the alluvial cover caused by bedrock topography will produce contrasts in the surface temperature. If temperature contrasts as small as 0.1 C can be resolved, a linear topographic feature having several metres of relief buried by 1.5 m of alluvium may be visible in thermal imagery acquired during January or August in the southwestern U.S. under optimal conditions. Thermal remote sensing may provide a means for delineating some buried faults, fluvial channels, and other features of interest on buried, granitic pediment surfaces.