STUDY OF VARIATION IN SEISMICITY OF NORTH WEST HIMALAYA

Abstract

Study of Seismicity of Himalaya is very fascinating for Geophysicists all over the world because it is one of the regions where two continental plates are not just colliding but one is moving into the other at relatively high speed producing folds, faults in the process. So, for the seismological study scientist need a reliable data and in this study we will check the reliability of the data, magnitude of completeness (Mc) of earthquake catalog along with the seismicity parameter a, b which can further be used in many Seismological studies. Catalogs include a complex mixture of real and man-made changes for which temporal variation of catalogs were observed using techniques described by Habermann (1983) for each Source zone and most of the magnitude signature obtained from the source zone were clear case of Detection Increase, which suggest us that there were installation of many Seismic Station in the region after year 2000. For obtaining variation in magnitude of completeness (Mc) of earthquake catalog and variation in the seismicity parameter a, b entire region was divided into 12 source zones Gupta (2006) and then for each source zone magnitude of completeness (Mc) and seismicity parameter a, b are obtained by using Entire Magnitude Range Method (EMR) modified by (Woessner et al., 2005). Magnitude of Completeness of 4.7 was obtained for entire region, b value from 0.72 to 1.4 was observed in the region.