Evaluation and comparison of the crustal structure of the Indus block up to Kutch region and Saurashtra region using GA inversion of surface–wave dispersion

Vishwa Joshi; B. K. Rastogi

Volume : V, Issue : V, May - 2015

Evaluation and comparison of the crustal structure of the Indus block up to Kutch region and Saurashtra region using GA inversion of surface–wave dispersion

Vishwa Joshi, B. K. Rastogi

Abstract :

&nbsp;We have computed Group velocities of the fundamental mode Rayleigh wave using an earthquake of&nbsp; MW 5.2 (Lat: 39.50Ë&scaron;N, Long: 73.81Ë&scaron;E). This earthquake was recorded at seven stations of Saurashtra region and eight stations of Kutch region by seismic network of Institute of Seismological Research, Gujarat (India). The&nbsp; period of observed group velocity data ranges from 6 to 60 sec for Saurashtra and 6 to 68 sec for Kutch. The dispersion curves have been inverted for crustal structure using Genetic Algorithm (GA) inversion; it gives the average crustal structure along the path. We have evaluated crustal structure of the Indus block up to Saurashtra and then up to&nbsp; Kutch. The thickness of crust up to Saurashtra is 43.61 km with S&ndash;wave velocity of 4.53 km/sec and thickness of crust&nbsp; up to Kutch is 44.91 km with S&ndash;wave velocity of 4.46 km/sec whereas previous study of Indus block up to Bhuj (Kutch)&nbsp; indicates 44.19 km thick crust with 4.39 km/sec S&ndash;wave velocity. According to these results, it is inferred that the crust&nbsp; of the Kutch region is thicker than that of Saurashtra region.