Fault traces in the arid arava valley floor, israel, revealed by RADARSAT surface roughness classification

Regional study of linear features, such as faults. joints, flexures, crustal fracturing and lithological contacts, using remote sensing techniques, have made important advances in geological research during the last decade. Radar digital data from satellites has gained increasing attention in the past few years. In the present study RADARSAT data is being used to investigate the tectonic configuration of an area in the Israel-Jordan Arava Rift Valley. Previous geological and geophysical studies have indicated the presence offaults in the valley floor, however surface expression is not obvious in the low relief and difficult access of the area. The Arava is a relatively flat arid area in which such radar response influences as surface slope and orientation are negligible or non-existent. Thus, the only property which can determine radar backscatter is surface roughness. In this work, the classification of radar surface roughness is shown to be particularly useful in tracing the extension of fault, recognized as lineaments, in the rift valley where they are covered by the recent superficial sediments. The relationship between surfaces formed by sand, pebbles, boulders or vegetation, singularly or in combination and identified by radar surface roughness, reveal the trace oflineaments.