Seafloor geomagnetic sounding near the 85�E ridge in the bay of Bengal

Abstract

Seafloor geomagnetic field variations in three components were recorded in the Bay of Bengal near the 85°E ridge, to investigate whether the negative gravity anomaly over the ridge is due to thick sedimentary deposit or due to a thick crust. Comparison of the X-, Y-and Z-variations in the vicinity of the 85°E ridge and near the continental margin suggests that a resistive thick crust underlies the 85°E ridge. The validity of conclusions arrived at from a simple inspection of magnetograms is supported by numerical calculations using a thin sheet approximation.