1. Lower-crust S-wave velocity beneath western Yunnan Province from waveform inversion of dense seismic observations.
- Author
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Gao, Xing, Su, Youliang, Wang, Weimin, Pei, Shunping, and Guo, Zhi
- Subjects
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SEISMIC wave studies , *MOHOROVICIC discontinuity , *CRUST of the earth , *GEOPHYSICS research , *EARTH (Planet) - Abstract
We use teleseismic body waveforms to explore S-wave layered velocity structures beneath 30 portable digital seismic stations deployed around western Yunnan Province. Results show that the Moho depth in this region is ∼40 km and decreases in general from north to south, consistent with previous geophysical studies. Associated with this lateral variation of the Moho depth, the lower crust above the Moho discontinuity has a 15–25 km thick zone with an S-wave velocity lower than that of the upper crust. This lower velocity zone might be interpreted as a lower crust weak channel, which may mechanically partially decouple the upper-crust deformation from the underlying mantle. Thus, the inverted S-wave velocity structure could provide new evidence for the lateral flow of lower crust in the build-up of the south-eastern Tibetan plateau. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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