Geological Hazards

Seismology, Seismotectonics and Seismic Microzonation GSI has a legacy of more than 150years of earth science studies. Along with geological mapping, mineral exploration and number of other earth science research, GSI has always nurtured earthquake related studies. Pioneering work by Thomas Oldham and R.D. Oldham in the 19th Century virtually laid the foundation of modern seismology. The Geological Survey of India has been carrying out macroseismic survey (post-earthquake damage surveys for assessment of intensity) of earthquakes for now over 135 years. The first account of such a study dates back to Cachar earthquake of 1869. Thomas Oldham, who investigated the event, later published a Catalogue of Indian earthquakes dating from historical times to 1869. Jones (1885) conducted studies for the 1885 Kashmir earthquake that took a toll of 3000 human lives and caused widespread destruction in the Kashmir valley. The Great Assam earthquake of 1897, one of the most severe and destructive manifestations of seismic energy release the world has witnessed so far, was investigated in detail by Sir R.D. Oldham. The accounts, observations and analyses of that catastrophe were brought out in the form of a Memoir (Vol. 29) of GSI. The first seismic zoning map of the country was prepared by GSI in 1935. With that beginning and consequent updating with state of the art technology, GSI has been engaged in multifarious earthquake studies including macroseismic survey of every great Indian earthquake, aftershock studies by establishingtemporary digital seismic networkto interpret causative fault and source mechanism, study of activefaults as seismic source, observational seismology with Broad Band observatories at Jabalpur and Nagpur, telemetered seismic network at Khandwa, Madhya Pradesh, tomographic studies, seismotectonic / neotectonic studies and seismic microzonation studies for urban centers etc. Bureau of Indian Standards delineates Seismic Zones of India with inputs from GSI. Indian sub-continent has a diverse tectonic setting. GSI made a neat contribution in bringing out the ‘Seismotectonic Atlas of India and it environs’, which is a comprehensive multi-thematic atlas encompassing integration ofgeological, geophysical, seismological information up to 1