Study of China lithosphere by receiver function and surface wave tomography
Time frame: 2006 - 2011
High-resolution seismic observation of the lithosphere is hampered due to a number of factors. (1) As a gradient transition zone and as an upper boundary of a low-velocity zone (asthenosphere), the lithosphere-asthenosphere boundary (LAB) is hard to detect by body waves or wide-angle seismic reflections; (2) Surface wave studies sometimes suffer from low resolution due to sparse station distribution. It has, however, been shown that the resolution of surface wave tomography can be greatly improved by including higher mode surface waves. The S receiver function method appears to provide another means to observe the LAB. Here we combine applications of P and S receiver function methods with multi-mode surface wave tomography to study the lithospheric structure of China. Surface wave models might be used to improve the receiver function estimates in two ways: firstly they can straightforwardly be used in a joint inversion, where they remove some of the ambiguities associated with inversions of receiver functions alone; secondly they can provide appropriate models for time-depth conversion of the receiver functions. Knowledge about the entire lithosphere, not only the crust, will significantly improve our understanding of plate tectonics of China and the Indo-Asian collision and of large intraplate earthquakes.
Dr. Xiaohui Yuan (GFZ Potsdam)
Eric Debayle (Université Lyon)
Keith Priestley (University of Cambridge)