The 26 January 2001 "Republic Day" Earthquake, India

Abstract

The Mw 7.6 Republic Day earthquake that shook the Indian province of Gujarat on the morning of 26 January 2001 was the most deadly in India's recorded history (Figure 1). One month after the earthquake official Government of India figures placed the death toll at 19,727 and the number of injured at 166,000. Preliminary indications are that 600,000 people were left homeless, with 348,000 houses destroyed and an additional 844,000 damaged. The Indian State Department estimates that the earthquake affected, directly or indirectly, 15.9 million people, nearly 50% of the population of Gujarat. More than 20,000 cattle were reported killed. Government estimates place direct economic losses at $1.3 billion, although more recent estimates indicate losses may exceed $5 billion. The Republic Day earthquake occurred on the Kachchh Peninsula (Figure 2), which has a long history of strong earthquakes (Bapat et al. , 1983). The region is bordered to the north and the south by ancient rift systems (Biswas, 1971, 1987, 1989; Srivastava, 1971). Structures within these rift systems (Rajendran and Rajendran, 1998, 2001) and on the Kachchh mainland (Malik et al , 2000) are now subjected to compressional stress and reverse faulting resulting from India's collision with Asia (Gowd, 1996; Chandra, 1977). Compresssional features appear to be of at least two different ages, with folding events occurring prior to 120 Ka and a distinct set of new features activated more recently (Rockwell, personal communication, 2001). The first historical Kachchh earthquake to attract international attention was the 1819 Allah Bund (Dam-of-God) earthquake, which created a 6-m-high, 6-kin-wide natural dam across the Puran or Nara River (which enters the Rann of Kachchh from the north). A lake 30 km in diameter, Lake Sindri, was formed south of the Allah Bund, and although this is now partly filled …