Crustal structure in the Himalayan and Tibet Plateau region from surface wave dispersion

Abstract

abstract Dispersion of Rayleigh and Love waves recorded at Seoul, Hong Kong, Shillong, New Delhi and Quetta by similar long-period seismographs has been studied for the Arctic region earthquake of 25th August 1964. The entire paths from the epicenter to the recording stations are continental. Waves recorded at Shillong, New Delhi, and Quetta pass through the high mountain regions of the Himalayas and Tibet Plateau while those recorded at Seoul and Hong Kong do not pass through these high mountain regions. Observed dispersion has been compared with theoretical dispersion curves computed for a three-layer earth model. This gives an average crustal thickness of about 45 km between the epicenter and Shillong, New Delhi and Quetta, 35-37 km between the epicenter and Seoul and Hong Kong and 65-70 km in the Himalayan and Tibet Plateau regions.