Active fault research in India: achievements and future perspective

摘要

This paper provides a brief overview of the progress made towards active fault research in India. An 8????m high scarp running for more than 80????km in the Rann of Kachchh is the classical example of the surface deformation caused by the great earthquake (1819 Kachchh earthquake). Integration of geological/geomorphic and seismological data has led to the identification of 67 active faults of regional scale, 15 in the Himalaya, 17 in the adjoining foredeep with as many as 30 neotectonic faults in the stable Peninsular India. Large-scale trenching programmes coupled with radiometric dates have begun to constraint the recurrence period of earthquakes; of the order of 500?￠????1000????years for great earthquakes in the Himalaya and 10,000????years for earthquakes of >M6 in the Peninsular India. The global positioning system (GPS) data in the stand alone manner have provided the fault parameters and length of rupture for the 2004 Andaman Sumatra earthquakes. Ground penetration radar (GPR) and interferometric synthetic aperture radar (InSAR) techniques have enabled detection of large numbers of new active faults and their geometries. Utilization of modern technologies form the central feature of the major programme launched by the Ministry of Earth Sciences, Government of India to prepare geographic information system (GIS) based active fault maps for the country.