2001 年 2001 巻 20 号 p. 112-126
The Kachchh falls under seismically active zone-V outside the Himalayan seismic belt, and forms a part of Stable Continental Region (SCR). In the span of 50 years the Kachchh has experienced two large magnitude earthquakes, i. e. the July 21,1956 Anjar with ML 7 and the 2001 event with Mw 7.6. No coseismic surface rupture was associated with the Bhuj earthquake, suggests movement along a blind thrust has resulted into extensive lateral spreading of water saturated near surface soil horizon giving rise to formation of numerous EW striking extensional cracks or normal faults and the longitudinal pressure ridges in the epicentral area around Budharmora and Morgar villages. Liquefaction in the low-lying areas comprising fine sediments was the common phenomenon observed during this earthquake.
By satellite photo interpretation sever a l traces of active faults were identified for the first time occurring in the pediment zones along the northern margins of Katrol Hill Range and Northern Hill Range respectively. The active faults have displaced along them the Late Quaternary alluvial fan deposits and colluvial debris, resulting into formation of the north facing fault scarplets. Our field observations reveal that none of the active faults have moved this time. Thus, it is suggested that these faults still have high potential to break large magnitude earthquake in future.