Eikonal surface wave tomography of central and eastern China

Zhou, Pengxiang1,2,3; Chevrot, Sebastien3; Lehujeur, Maximilien3,4; Xia, Shaohong2,5; Yu, Chunquan1,5

2022-09-05

10.1093/gji/ggac296

GEOPHYSICAL JOURNAL INTERNATIONAL   Impact Factor & Quartile

0956-540X

1365-246X

Eikonal tomography has become a key approach to image lithospheric structures with surface waves recorded by dense regional arrays. Its main advantage is that phase velocities can be determined directly from phase measurements without resolving a tomographic inverse problem. Here, we apply a new smoothing spline eikonal tomography approach to a selection of 40 large (M-w larger than 6.5) teleseismic events recorded by the permanent seismic stations of the CEArray. We first apply a time-frequency filter to isolate the fundamental mode of Rayleigh waves and cross-correlate the cleaned and isolated surface wave records to measure precise relative traveltimes. The phase measurements are then unwrapped and corrected for cycle skipping. Finally, we derive phase-velocity maps from the gradient of the reconstructed traveltime fields, using the eikonal equation. We obtain finely resolved phase-velocity maps from 25 to 150 s period that are inverted to obtain a 3-D shear wave velocity model which is in good agreement with previous tomographic studies. The lithospheric architecture emerging from the phase-velocity maps and 3-D S-wave velocities correlates with surface geology and major tectonic provinces. In particular, the architecture of the narrow rift systems, the South China Craton, and the North China Craton (NCC) are revealed with unprecedented details. The South China Craton is characterized by very high velocities beneath the Sichuan Basin. The NCC shows more complex structures with two high-velocity anomalies beneath the Ordos Basin and the southeastern NCC and low-velocity anomalies beneath the Cenozoic rift systems.

Image processing Seismic tomography Surface waves and free oscillations Cratons Eikonal tomography

SCI

English

First

National Natural Science Foundation of China["42076071","U1701641"] ; Key Special Project for Introduced Talents Team of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[GML2019ZD0204] ; China Scholarship Council[201804910670] ; Guangdong Research Foundation[2019BT02H594] ; Key Research and Development Plan of Hainan Province[ZDYF2020198]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000849880100004

OXFORD UNIV PRESS

GEOSCIENCES

Web of Science

1.Southern Univ Sci & Technol, Dept Earth & Space Sci, Shenzhen 518000, Peoples R China
2.Chinese Acad Sci, South China Sea Inst Oceanol, CAS Key Lab Ocean & Marginal Sea Geol, Guangzhou 510000, Peoples R China
3.Univ Paul Sabatier, Observ Midi Pyrenees, CNRS, IRD,CNES,GET,UMR 5563, F-31400 Toulouse, France
4.Univ Gustave Eiffel, GERS GeoEND, F-44344 Bouguenais, France
5.Southern Marine Sci & Engn Guangdong Lab Guangzho, Guangzhou 510000, Peoples R China

Zhou, Pengxiang,Chevrot, Sebastien,Lehujeur, Maximilien,et al. Eikonal surface wave tomography of central and eastern China[J]. GEOPHYSICAL JOURNAL INTERNATIONAL,2022,231(3).

Zhou, Pengxiang,Chevrot, Sebastien,Lehujeur, Maximilien,Xia, Shaohong,&Yu, Chunquan.(2022).Eikonal surface wave tomography of central and eastern China.GEOPHYSICAL JOURNAL INTERNATIONAL,231(3).

Zhou, Pengxiang,et al."Eikonal surface wave tomography of central and eastern China".GEOPHYSICAL JOURNAL INTERNATIONAL 231.3(2022).