National Centre for Seismology

Considering the importance of earthquake monitoring and seismological research in India, since long it has been realized that a dedicated institute is required. Accordingly, the Seismology Division and Earthquake Risk Evaluation Centre of India Meteorological Department, have been merged with the newly created National Centre for Seismology (NCS) in August 2014, as an attached office of the Ministry of Earth Sciences. In addition to earthquake monitoring NCS is involved in providing seismic microzonation of mega cities lying in seismic hazard zones and seismological research. The Centre's objective is to improve understanding of earthquake processes and their effects through monitoring and seismological research.

Earthquake monitoring

Earthquakes in the Indian subcontinent occurs due to the northeastward movement of Indian plate and its interaction with the neighbouring Eurasian plate in the north and Sunda plate in the east. Majority of the earthquakes occur in the plate boundary regions, however, a few damaging earthquakes have occurred in the plate interior regions as well. A few damaging earthquakes in the plate boundary regions are, 1897 Shillong plateau, 1905 Kangra, 1934 Nepal-Bihar, 1950 Assam (now Arunachal), 2004 Sumatra Andaman, 2005 Kashmir and 2015 Gorkha earthquakes. In the plate interior regions, damaging earthquakes occurred in 1993 at Killari, 1997 at Jabalpur, and in 2001 at Bhuj.

Earthquake monitoring in the country started as early as in 1898 with the establishment of an earthquake observatory at Alipore, Kolkata, after the great Shillong Plateau earthquake in 1897. After independence, the number of observatories increased to 15 and after the worldwide seismograph station network in 1964, the number increased to 45. After the 1993 Killari earthquake, the digital era of instrumentation started and currently NCS has 84 observatories spread all over India. Special emphasis has been given to the NE India and Delhi region by installing dense networks in these two regions. Further, a dedicated Real Time Seismic Monitoring Network provides continuous data to Tsunami Warning Centre at INCOIS. All observatories are equipped with VSAT communication facility for transfer of data in real time to Operational Centre. Continuous seismic data of seismological observatories at Minicoy, Port Blair and Shillong is being shared globally. With the current network, any earthquake of magnitude down 3.5 can be located within 5 to 10 minutes with reliable accuracy. The information on earthquake parameters is disseminated to all concerned state and central government departments through SMS, FAX, and Email.

Seismic microzonation

Seismic microzonation is a multi-disciplinary and multi-institutional effort, which has direct application in disaster mitigation and management, urban development, planning, design and construction, and risk assessment to existing life and property, defence installations, heavy industry and public utilities and services. Accordingly, development of seismic microzonation maps of major urban centres in the country has been recognized as one of the priority areas in NCS. During the last few years, efforts have been made to take up microzonation studies in a few cities. Recently seismic microzonation (1:10,000 scale) of Delhi has been completed. In view of the importance of the seismic microzonation in mitigating future disasters, this exercise has been initiated for 30 important cities of India.

Seismological research

NCS is actively involved in seismological research related to estimating shallow and deep crustal structure in various tectonic domains of Indian land mass, understanding earthquake occurrence processes in the Himalaya, Indo-Burmese and Andaman Sumatra arc and also in plate interior regions, crustal deformation measurements in the plate boundary and plate interior regions.