Since the India-Eurasia collision began approximately 45 Ma ago, the Indian plate has penetrated northwards about 2000 km, producing the highest continuous topography on Earth, the Himalayas and the Tibetan plateau. A large part of my Ph.D. thesis research between 1993 and 1998  concentrated on determining crustal and upper-mantle structure of the plateau and its related tectonic implications. I participated the 1991-1992 Sino-US Tibet PASSCAL experiment in which we deployed 11 broadband stations across the plateau. Using this valuable data, I have derived a 1-D crustal model for the Tibetan Plateau using both teleseismic receiver functions and broadband regional waveforms, and with it determined focal depths and source mechanisms of about 50 Tibetan earthquakes.
The results confirmed the shallow seismicity in the plateau. Additionally we found three sub-crustal events under the Himalaya and Indus-Zangbo suture zone, which indicate a very different temperature and stress regime in the uppermost mantle here from the rest of the plateau. Most recently, I identified a 15 to 20 km Moho offset along the northern margin of the plateau. Such a sharp Moho relief implies a weak Tibetan crust growing vertically in response to the indentation of India from the south and blockage by the Qaidam to the north.