ELECTRICAL RESISTIVITY BASED SHALLOW CRUSTAL DEFORMATION ANALYSIS IN AN ACTIVE SEISMIC ZONE

Abstract

This paper aims to assess the shallow crustal deformation in a highly seismic-prone zone of northeast India. For that purpose, Tripura University campus has been selected which is nearly 8 km away from Agartala city. The field work was conducted by using electrical resistivity meter. Vertical Electrical Sounding or VES method of resistivity survey was adopted for measuring the electrical resistivity and structural analysis of the study area. Total four VES points were recorded namely near the Department of Physics, Department of Geography and Disaster Management, Teachers’ Residential area and Girls’ Hostel. The recorded data was measured and two different electrical profiles were drawn i.e. (a) Physics building to Geography buildings and (b) teachers’ quarters to Girls’ Hostel. From the electrical resistivity profiles, a clear break in resistivity characters has been observed in the western part which is located near the Tripura University Girls’ Hostel. This clearly proves that a deformation occurred in this area below 4 m depth and it can be very dangerous if a high magnitude seismic slip takes place. From this observation, this hostel is detected as the most risk prone building. Apart from that, the teachers’ quarters near the Girls’ hostel have also been detected as equally risk prone. From this point of view it can be recommended that construction of heavy buildings should be restricted in Tripura University campus as the subsurface deformation zone can create faulting during high magnitude earthquake.