Abstract:
Gumbel extreme value theory has been applied to estimate the probability of occurrence and
return period of the largest earthquake in Gujarat region India. The expected extreme based
magnitude of 49 year (1965-2013) seismicity data of one year extreme values of earthquake for
region have been plotted. The yearly expected number, mean return period and risk for
occurrence of earthquake in the consider region have been estimated. The most probable medium
size earthquake that may occur in the region are estimated and reported. The result presented in
this study is only best long-term estimate subject to the limitation of the earthquake data.
Seismic hazard assessment refers to an opinion of ground motion parameters at any site or
region. In the present study seismic hazard has been performed for the Gujarat region using the
seismicity data provided by IDM, GSI, USGS, ISC, GERI, ISR. Assuming one third of the total
fault length as rupture length of MCE, maximum magnitude to each source is assigned. After the
judgment of distance of zone of energy release two different attenuation models are used to
define peak horizontal acceleration based on shortest distance between sites and sources. It has
been seen that among major fault in Gujarat region cambey west fault (CWF) produces
maximum acceleration (Ah) using attenuation relationships by SHARMA (2000) equal to
0.1469g and 0.061181g using attenuation relationships Boore, Joynosard and Fumal(1993)
