First multi-scale, finite-frequency tomography illuminates 3-D anatomy of the Tibetan Plateau

Abstract

With a new multi-scale parameterization, 3-D images from finite-frequency seismic tomography, including the very first images beneath central Tibet from S-waves, reveal that regions of low electric resistivity in the crust, previously observed along active rifts in southern Tibet, correlate well with regions of low P-and S-wave speeds (V). However, such regions are not interconnected, indicating that a prevailing south-directed, channel-like crustal flow seems inactive or this popular geodynamic model needs modification. In the upper mantle, there is no clear indication of regional down-welling between depths of 100 to 400 km. Instead, a strong, lateral boundary between high and low V extends up to 33N, marking the northern limit of sub-horizontally advancing Indian lithospheric mantle. Copyright © 2010 by the American Geophysical Union.