Preliminary results from very long period data collected by a broad band digital seismic station

Abstract

Preliminary analysis of seismograms recorded by a wide band high dynamic range digital seismograph installed under a collaborative research programme between IPG, Paris and NGRI, Hyderabad, indicates that the crust and upper mantle structure below the Indian continent are characterized by high velocity up to a depth of 500 km. Both the group and phase velocities in the period range of 100-350s are found to be faster by 3-4% and 1-3% respectively compared with global models such as the preliminary reference earth model.