Active deformation measurements in Manipur

Environmental protection needs strengthening of disaster prevention measures to ensure a long term structural stability. Monitoring subsurface fault(s) is one of the useful practical applications of new technology developments. Subsurface structure and fracture mechanics play important role in stability assessment research. Development of 3D fault deformeter is a state-of-the-art technique in monitoring shallow subsurface deformations in tectonically active areas. Such an instrument has been developed by a research team at the Energy Utilization Research Institute (EURI), Advanced Industrial Science and Technology (AIST), Tsukuba, Japan. This instrument is basically designed to monitor the behavior of joints/faults’ in rock masses. It can be installed in unstable rock slopes under surveillance, where relative displacement in 3D can be measured in a borehole intersecting a major discontinuity in the rock mass.
The Manipur falls under a high seiemic zone, zone V in seismic zoning map of India, where the India and Myanmar plates collide in a subduction mechanism. The regional fault, Churachandpur thrust (CMT), is believed to be the western boundary of the Indo Mynamar subduction zone. Seismological evidences suggest that the fault is tectonically active due to strike slip movement. The morphotectonic evidences reveals right lateral movements along the fault. We selected this fault for monitoring of its subsurface deformations using the 3D fault deformeter. The installation of the deformeter is a part of the DST sponsored project funded to the Earth Sciences Department, Manipur Unniversity. The installation of the 3D fault deformeter is a first attempt of its kind in the country to measure the subsurface deformations in active tectonic terrain.