Seismotectonic study of Kishtwar region of Jammu Province using local broadband seismic data

Two moderate earthquakes of Mw 5.7 on the first of May and Mw 5.2 on the second of August occurred in the Kishtwar region in the year 2013. Our broadband seismic observatories located in the region recorded these events and the aftershocks. We analyzed these data to understand the seismotectonics of this region. Most of the events were located between 33.03° to 33.29° N latitude and 75.40° to 76.07° E longitude. Focal depths of these shallow earthquakes range from 7 to 12 km and are confined between Panjal Thrust (PT) and Kishtwar Window (KW). Spectral analysis of these events reveals that stress drop, source radius, corner frequency, and moment magnitude varied between 3.3 and 70.1 bars, 0.121 and 3.55 km, 0.397 and 6.06 Hz, and Mw 2.2 and Mw 5.7, respectively. The low stress drop of small-magnitude earthquakes reveals the brittle nature of the upper crust which is coincident with the field observations. The variation of stress drop with magnitude shows positive correlation whereas no such relation was observed between stress drop and depth of focus. The b value calculated (0.83) for the area reveals high stress accumulation within the incompetent rock zones in the area.     

Science and technology based earthquake risk reduction strategies: The Indian scenario

Science and Technology (S & T) interventions are considered to be very important in any effort related to earthquake risk reduction. Their three main components are: earthquake forecast, assessment of earthquake hazard, and education and awareness. In India, although the efforts towards earthquake forecast were initiated about two decades ago, systematic studies started recently with the launch of a National Program on Earthquake Precursors. The quantification of seismic hazard, which is imperative in the present scenario, started in India with the establishment of first seismic observatory in 1898 and since then a substantial progress has been made in this direction. A dedicated education and awareness program was initiated about 10 years ago to provide earthquake education and create awareness amongst the students and society at large. The paper highlights significant S & T efforts made in India towards reduction of risk due to future large earthquakes.