Heat flow variation from bottom simulating reflector in the Kerala-Konkan basin of the western continental margin of India

Abstract

The base of the gas-hydrate stability field, representing the bottom simulating reflector or BSR, is observed over a closely spaced grid of multichannel seismic data in the Kerala-Konkan (KK) basin of the western continental margin of India (WCMI). The data reveal that gas-hydrates occur in the KK basin at places where water depth exceeds 1500 m. The thickness of the gas-hydrate stability field, inferred from BSR on seismic data, ranges between 190 and 340 m. The geothermal gradient, estimated from BSR, ranges from 40 to 60°C/km. The corresponding heat flow values vary between 36 to 54 mW/m2. The result shows a seaward increase in geothermal gradient in the KK basin and brings out relatively high heat flow to the north and low heat flow in the south of the study area. The high heat flow distribution is explained by the decrease of sediment thickness proximal to the ocean/continent boundary.