Department of Civil Engineering

Indian Institute of Science, Bangalore

Seismic History (activity) of region

The Peninsular Gneissic Complex occupies major part of the study area. Further, findings from geologists have shown that in the southern Karnataka the faults/ lineaments are reactivated. Valdiya (1998) highlighted that the seismic activity is generally confined to linear belts related to transcurrent and terrain-bounding faults and shear zones, implying that the Precambrian faults are being reactivated in the present time based on purely geological studies. The morphology of Karnataka shows that the series of water falls, cascades and rabid along the Cauvery river, particularly between Sivasamudram in Karnataka and Mettur in Tamil Nadu. This is attributed to the reactivation of Precambrian faults across part of the old course here and lateral displacement of the uplifted blocks, giving rise to change in the course of the river as shown in Figure (Valdiya, 1998). Figure shows the active faults speculated at present by Valdiya (1998) in south of Bangalore on either side within 100 kms.

Active faults present close to Bangalore (after Valdiya, 1998)

Large number of earthquakes with different magnitudes has occurred very often in this region (Ramalingeswara Rao and Sitapathi Rao, 1984; Bansal and Gupta, 1998). In recent years much of the seismic activity in the state of Karnataka has been in the south, in the Mysore-Bangalore region (Ganesha Raj and Nijagunappa, 2004). Seismotectonic map from Project Vasundhara (1994) also shows that there are active faults that triggered earthquake magnitude of 2 to 4 close to Bangalore. Ganesha Raj and Nijagunappa (2004) have also highlighted the need to upgrade the seismic zonation of Karnataka; particularly the areas surrounding Bangalore, Mandya and Kolar to zone III rather than the current zone II as these areas are quite active, based on the analysis carried out using remote sensing data and neotectonic activity in the area.

Webpage is maintained by

Dr P Anbazhagan

Lecturer

Department of Civil Engg

Indian Institute of Science

Bangalore, India 560012

Suggestions and queries may be directed to Dr P Anbazhagan

Copyright  All Rights Reserved.

This page was last updated on August 25, 2011