Using paleo-liquefaction features to determine the likely source, magnitude and ground accelerations of pre-historic earthquakes in the Kashmir Basin (Northwestern Himalaya), India

Abstract

Few surface fault scarps or other obvious surficial geomorphic features record pre-historic earthquakes in the Kashmir Basin (KB) in the northwestern Himalaya Mountains of India. We therefore identified liquefaction features exposed in various cuts and trenches in the area, documented these on geological logs, and geotechnically characterized them in order to determine the likely causative earthquake(s), the source area, the inferred paleo-magnitude and the relative ground accelerations. We calculate that the magnitude of liquefaction-producing earthquakes in the KB ranged between 6.4 and 7.3 Mw, and that the peak ground accelerations were on the order of 0.29–0.64 g. We propose that the techniques employed, the data obtained and the technical interpretations, are potentially useful, not only for local general landuse planning and site-specific hazard reduction, but may also be extrapolated to similar tectonically active regions.