3-D Shear Wave Velocity Structure of South China from Rayleigh Wave Tomography
Abstract
We do joint inversion of ambient noise and teleseismic Rayleigh wave by using data from 440 permanent seismic stations and 310 temporal seismic stations for studying lithospheric structure beneath South China. Rayleigh wave phase velocity dispersions are extracted from ambient noise data in periods range from 6 s - 80 s and teleseismic data in periods range from 30 s - 140 s. Data from long-term deployed stations are processed using the phase-weighted stacking, thus the signal to noise ratio of stacked noise-correlation is greatly improved at longer periods. Phase velocity map results from noise and teleseismic data are consistent in the overlap Periods. Then we invert shear velocity by Markov Chain Monte Carlo method and construct a 3-D crust/mantle shear wave velocity model of South China. Our new results correspond surface topography well, and exhibits the pattern of major tectonic structures, e.g. Qinling-Dabie Orogenic Belt, Tancheng-Lujiang Fault, Hainan mantle plume. The velocity structure of the eastern South China in mantle depth is much similar to eastern North China, which infers that the lithosphere of the eastern South China has already been destroyed although there is low seismicity. At the western South China, there still exists a thick lithosphere, however in its margin the lithosphere seems in delamination process.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.T21F0402N
- Keywords:
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- 8120 Dynamics of lithosphere and mantle: general;
- TECTONOPHYSICS;
- 8121 Dynamics: convection currents;
- and mantle plumes;
- TECTONOPHYSICS;
- 8170 Subduction zone processes;
- TECTONOPHYSICS;
- 8180 Tomography;
- TECTONOPHYSICS