A reappraisal of active faults in central-east Iran (Kerman province)

Abstract

Fault lineaments are the main input data in earthquake engineering and seismology studies. This study presents a digitally-based active fault map of the Kerman region in central-east Iran which experienced several devastating earthquakes on poorly exposed and/or not identified active faults. Using Landsat 8 data, we have carried out the image-based procedures of fault mapping, which include applying the contrast stretching technique, the principal component analysis, the color composite technique, the spectral rationing, and creating the false-color composite images. Besides, we have cross-checked the resulting map with the geological maps provided by the Geological Survey of Iran to decrease the associated uncertainties. The resulting map includes 123 fault segments, still, a part of which has been expressed in the previously compiled active-fault maps of Iran. Indeed, the new one is mapping the poorly exposed active faults, so-called secondary faults, which are able to produce strong events. These faults are primarily associated with poorly defined areas that accommodate low levels of seismicity; however, sporadic strong events are likely to occur. It has also been investigated that these kinds of faults are seismogenic and are able to produce destructive events. In total, the outcome of this study can also be jointed with seismic studies for investigating parts of the earthquake activity in central-east Iran, in particular for the fault-based approaches in impending earthquake-resistant buildings.