HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Mitra, S. Articles by Rai, S. S. Search for Related Content GeoRef GeoRef Citation

Shear-Wave Structure of the South Indian Lithosphere from Rayleigh Wave Phase-Velocity Measurements

¹ Bullard Laboratories
University of Cambridge
Cambridge CB3 OEZ, United Kingdom
 (S.M., K.P.)
² Indian Institute of Astrophysics
Bangalore, India 560 037
 (V.K.G.)
³ Center for Mathematical Modelling and Computer Simulations
Bangalore, India 560 037
 (V.K.G.)
⁴ National Geophysical Research Institute
Hyderabad, India 500 007
 (S.S.R.)

^* Present address: Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, India 721 302.

We investigate the upper mantle shear-wave speed structure beneath the south Indian shield by measuring and modeling fundamental mode Rayleigh wave phase-velocity dispersion. Observed phase velocities for the south Indian shield closely match those observed for the Canadian shield. We constrain the south Indian crust using published receiver function results and invert the dispersion data for upper mantle shear-wave structure. The 155-km-thick seismic lithosphere of the south Indian shield is composed of a 35 km-thick, two-layer crust and a 120-km-thick, high-velocity upper mantle lid. Beneath the Moho the average S_n wave speed is 4.7 km sec^–1. Both S_n travel times data and the dispersion data suggest a positive sub-Moho shear-wave speed gradient. Beneath the seismic lithosphere there is a low- velocity layer where the shear-wave speed drops to 4.4 km sec^–1.