Tectonic Geodesy

Tectonic Geodesy group of the institute has established around 150 continuous GPS sites in the tectonically significant regions, namely, Andaman Sumatra subduction zone, Garhwal-Kumaun Himalaya, Kashmir and Ladakh Himalaya and Indo-Burmese arc in the plate boundary regions, and Shillong plateau, Koyna-Warna, Godavari and Delhi-Aravalli regions of the intraplate region. Besides these dense networks, the group has also established permanent GPS sites throughout India to constrain Indian plate motion and to understand the internal deformation of the plate interior regions. As a part of the Indian Scientific Expedition to Antarctica, to estimate the plate motion and to understand the causes of crustal deformation in the seismically quiet continent, Antarctica, the group has established one permanent GPS and Seismic observatory at the Indian base station, Maitri. The group is well-equipped to archive, process, and model GPS data for crustal deformation, ionosphere and water vapour studies.

The GPS data from these sites have been utilized to understand the Indian plate motion and strain accumulation in the plate boundary and intraplate regions of India, estimation of earthquake source parameters, coseismic TEC variations, etc. Evidence of strain accumulation in the Andaman region for the 2004 Sumatra-Andaman earthquake, estimation of the source parameters of the 2004 earthquake and its postseismic deformation provide insights into the mechanism of deformation and earthquake cycle in the region. Identification of a major plate motion accommodating fault, the CMF, in the Indo-Burmese wedge using GPS measurements is a major achievement of the group.

The group has proposed that the Karakoram fault in the Ladakh Himalaya is not a major fault and its role in the Himalayan arc deformation is limited. The Garhwal Kumaun GPS network of the group is the most dense network, anywhere along the Himalayan arc. The results from these data indicate that the strain accumulation in the Outer and Lesser Himalaya is quite homogeneous. In the Indian plate interior region, the deformation is localised and very low. Even in the reservoir triggered seismicity region of Koyna Warna, the deformation is as low as <0.5 mm/year .

Head of the group

Dr. Gahalaut V. K

Dr. Gahalaut V. K

Chief Scientist

Group Members

Dr. Joshi Catherine K

Dr.Joshi Catherine Karra

Senior Principal Scientist

Dr. Saroj Kumar Mondal

Dr. Saroj Kumar Mondal

Senior Scientist

Simhadri Naidu M

Mr. Simhadri Naidu M

Senior Technical Officer(1)