Study of the aftershock activity and source parameters of Latur earthquake of September 30, 1993

A total of 45 stations were operated by different agencies to record the aftershocks of the september 30, 1993 Latur earthquake. In the present study 220 aftershocks were located using the combined data set. Most of the epicentres follow the course of river Tirna and confined to area of 10 km radius. To homogenise the estimation of magnitudes an empirical relation for estimating magnitude from signal duration, Ms = -1.6757 +/- 1.9484 log D, is derived, where Ms is me surface wave magnitude and D is the total signal duration in sec. The magnitudes can be estimated with an accuracy of + 0.24 units using the above relation. Focal mechanism solutions for six aftershocks are reported in this study. The majority of the solutions are in agreement with the solution of the main shock. The pressure axis as determined from the focal mechanism solutions of the aftershocks is oriented along NE - SW direction.