Indian earthquake may serve as analog for New Madrid earthquakes



On January 26, 2001, Republic Day in India, a Mw-7.7 reverse-fault earthquake occurred in the Kachchh region of the state of Gujarat. The closest plate boundary lies many hundreds of kilometers away The earthquake was felt over 2000 km away and over an area more than 16 times that of the Mw-7.8 1906 San Francisco earthquake. No field investigation has yet found unequivocal evidence of surface rupture; highly unusual for an earthquake of this size. Also anomalous are the depths of aftershocks [Bodin et al., 2001], which suggest that the main rupture may have propagated into the lower crust. Liquefaction was extensive and occurred at great distances, probably reflecting the considerable thickness of unconsolidated sediments and the extremely shallow water table within the region. The Bhuj earthquake occurred in an old rift system, and the section to the east of Kachchh is a well-known seismic zone that sustains felt earthquakes on a regular basis.