Accession Number : ADA325890

Title :   Regional Wave Propagation Characteristics in the Middle East and Southern Asia,

Corporate Author : NEW MEXICO STATE UNIV LAS CRUCES DEPT OF PHYSICS

Personal Author(s) : Rapine, Richard ; Ni, James ; Hearn, Tom

PDF Url : ADA325890

Report Date : OCT 1996

Pagination or Media Count : 42

Abstract : The regional seismic waves Pn, Sn and Lg were used to map lateral variations of attenuation in the crust and upper mantle. Propagation efficiencies of Sn and Lg were qualitatively analyzed by ranking their amplitudes relative to the P-wave coda. Efficient Sn propagation is observed in the Tien Shan, Tarim Platform, southern Tibet, Yangzi Paraplatform and Sino-Korean Platform. We have confirmed previous studies by finding a lack of Sn transmission in north central Tibet, the Ryukyu and Japan Arcs, Burma and the Baikal Rift. An important observation, which has not been previously reported, is that Sn does not propagate across Mongolia. The elimination of Sn and recent volcanism in north central Tibet and Mongolia suggest that there is partial melt in the upper most mantle beneath those regions. High frequency Lg waves propagate efficiency for most of China, Indochina and Mongolia. Lg signals are attenuated within central Tibet as well as along its southern boundary.

Descriptors :   *WAVE PROPAGATION, *SEISMIC WAVES, MIDDLE EAST, EARTH CRUST, ATTENUATION, CHINA, EARTH MANTLE, FAR EAST, BURMA.

Subject Categories : Geology, Geochemistry and Mineralogy
      Seismology

Distribution Statement : APPROVED FOR PUBLIC RELEASE