Deep weathering, vegetation and fireburn Significant obstacles for geoscience remote sensing in Australia

Abstract

Large areas of the land surface of Australia retain effects of prior weathering events, to tens or hundreds of metres depth, which altered previously-exposed rocks to clays and reconcentrated various minerals such as iron oxides, carbonates and silica. In such areas data about surface mineralogy obtained by remote sensing may not relate to rocks at depth beneath the weathered zone. Although almost three-quarters of Australia is arid, that desert region has significant vegetation cover which can be a major remote sensing noise problem for the geoscientist attempting to detect spectral signatures of various rocks and minerals. Fireburn scars are another serious vegetation-related problem, for they result in significant vegetation-density variations across large tracts of country, especially in the arid zone. Geoscience research in Australia must overcome, or reduce, the impact of such environmental problems if remote sensing is to realize its full potential. This paper outlines the problems, their environmental settings and magnitude and the approaches to remote sensing applications being developed to overcome their effects.