Document Type : Seismology and Engineering Seismology
St. Louis University, Missouri
Landsat TM data were used in the study of neotectonics of the Tabas region in eastern Iran to assess drainage pattern and migration model of rivers. Evaluation and inspection of active tectonic processes and their effects such as earthquakes is of great importance in earthquake hazard analysis in any area. Since most processes directly related to seismic risk are not expressed in ways measurable from ground or satellite observations, using morphotectonic indicators of active tectonics may be useful for identifying these events. In this paper, the focus lies on the changes in the drainage network and the migration of rivers to get a clear understanding of active tectonics in the area. The relief in the area is remarkable due to its sharp contrasts and the multitude and variability of the morphological elements. Various geomorphic features supporting recent tectonic movements were deciphered from the various remotely sensed data. These include: strike slip faults, fault line scarps, triangular facets, uphill facing scarps, pressure-ridges, and abrupt changes in topographic slope angles along fault traces, offset drainage, truncated fans and beheaded drainage channels. Subsequently the focus of active deformation seems to have shifted northwest, and more precisely in an anti-clockwise direction, to where the most active zone of deformation is now buried in the desert of the Tabas plain.