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Balaji, S.
SEISMIC PRONE LINEAMENTS OF TAMIL NADU, INDIA AND ITS IMPACT
ON ENVIRONMENT — AN ANALYSIS THROUGH REMOTE SENSING
S.BALAJI * SM.RAMASAMY **
*Geophysicist
Central Ground Water Board
Kesavadasapuram
Trivandrum, Kerala, India
telenet@techpark.net
** Director
Centre for Remote Sensing
Bharathidasan University
Tiruchirapalli, Tamil Nadu, India
smr(g)bdu.ernet.in
Key words: Seismicity, lineaments/fractures/faults, Remote Sensing, Pleistocene
Tectonism
ABSTRACT
The Peninsular shield of India was thought as a aseismic region but the frequent earth tremors, at many
places, of late, suggest that it is also seismic prone. The violent earthquake in 1994 at Latur, Maharastra
state has justified the fact. The Latur catastrophic event not only devastated the whole of Latur village but
also claimed many precious lives. The tectonics of a region plays a crucial role in many of the major
earthquakes around the world. The Tamil Nadu state in South India is no exception to the onslaught of this
event. Several earth tremors have been recorded right from 1823 till date in various parts of the state. The
seismological and remote sensing analysis has shown that most of the earth tremors are falling along
Precambrian faults/lineaments reactivated in Quaternary times and Pleistocene faults/lineaments. The
occurrence of earth tremors in South India may be attributed to the reactivation of lineaments/faults, which
are trending in NE-SW, NW-SE and N-S directions and the reactivation of lineaments/faults may be
ascribed to the movement of the Indian plate towards Tibetan plate. In seismological analysis, the satellite
Remote Sensing gives a clear picture of regional lineaments/faults of tectonic importance and thus plays a
vital role in seismic concepts.
1.INTRODUCTION
The Southern India which is otherwise called as Peninsular shield was hitherto regarded as a stable zone
free from seismicity but the recent earth tremor which occurred in Latur, Maharastra state in 1994 and the
earth quake of 1900 in Coimbatore to a magnitude of 6.5 (Richter scale) have broken the conviction of the
geoscientists as it no longer to be so. The frequent earth tremors which have been triggering on and off in
various parts of Tamil Nadu state too justify the same and the faults/lineaments play a vital role for the
cause of the earth tremors in South India which dissipate the accumulated strain in the form of earth
tremors. These lineaments/faults of tectonic importance are well manifested in satellite imagery. Hence, in
order to understand the role of lineaments/faults and Remote Sensing in seismicity, this study has been
taken up.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.
101