Structure of the Gonghe Sedimentary Basin in the northeastern Tibetan Plateau: evidence from teleseismic P waves recorded by a dense seismic array

Deng, Yufeng1,2,3; Li, Zhiwei4; Huang, Song1,2; Xu, Ya1,2; Hao, Tianyao1,2,3; Bao, Feng5; Zhang, Senqi6; Li, Shengtao6; Jia, Xiaofeng6; Tian, Puyuan6; Zhang, Shengsheng7; Zang, Nan8; Zhang, Wei8

2023-07-27

10.1093/gji/ggad327

GEOPHYSICAL JOURNAL INTERNATIONAL   Impact Factor & Quartile

0956-540X

1365-246X

The Gonghe Basin in the northeast Tibetan Plateau presents significant potential for hot dry rock (HDR) geothermal resources. A 1990 Mw 6.4 earthquake in the basin furthers the need for an improved understanding of its sedimentary structure. In this study, we utilize data from a dense seismic array of 88 short-period seismometers deployed at an interstation spacing of approximately 3 km to scrutinize the sedimentary structure of the Gonghe Basin. By analysing teleseismic P waveforms, we identify P-to-S converted waves (Ps wave) originating from the sedimentary basement. We then determine the delay time between the Ps waves and the direct P waves (P wave) through waveform cross-correlation. By integrating this delay time with empirical velocity structure models, HDR borehole data and results from teleseismic receiver function analysis, we derive a sediment thickness model of the Gonghe Basin for the Qabqa geothermal area. Our findings reveal a gradual increase in sediment thickness from around 500 m in the east to approximately 3000 m in the west, which is consistent with other geophysical surveys and borehole data. The thick sediments in the basin could potentially serve as an excellent thermal storage cover for HDR. The strong ground motion simulation using our sediment thickness model shows that thick sediments can amplify seismic waves, increasing the risk of seismic hazards. Moreover, our study indicates that the clear Ps waves can be effectively extracted to construct a dependable sediment thickness model using teleseismic P waves recorded by a short-period dense seismic array.

Time-series analysis Body waves Crustal imaging Earthquake ground motions Wave propagation

SCI

English

Others

National Natural Science Foundation of China["41974064","42174076"] ; China Geological Survey[DD20190131]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:001056958800002

OXFORD UNIV PRESS

GEOSCIENCES

Web of Science

1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Petr Resources Res, Beijing 100029, Peoples R China
2.Chinese Acad Sci, Innovat Acad Earth Sci, Beijing 100029, Peoples R China
3.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China
4.Inst Spacecraft Environm Engn, Sci & Technol Reliabil & Environm Engn Lab, Beijing 100094, Peoples R China
5.Chinese Acad Sci, Innovat Acad Precis Measurement Sci & Technol, Wuhan 430077, Peoples R China
6.China Geol Survey, Ctr Hydrogeol & Environm Geol Survey, Baoding 071051, Peoples R China
7.Inst Hydrogeol & Engn Geol Qinghai, Xining 810008, Peoples R China
8.Southern Univ Sci & Technol, Dept Earth & Space Sci, Shenzhen 518055, Peoples R China

Deng, Yufeng,Li, Zhiwei,Huang, Song,et al. Structure of the Gonghe Sedimentary Basin in the northeastern Tibetan Plateau: evidence from teleseismic P waves recorded by a dense seismic array[J]. GEOPHYSICAL JOURNAL INTERNATIONAL,2023,235(2).

Deng, Yufeng.,Li, Zhiwei.,Huang, Song.,Xu, Ya.,Hao, Tianyao.,...&Zhang, Wei.(2023).Structure of the Gonghe Sedimentary Basin in the northeastern Tibetan Plateau: evidence from teleseismic P waves recorded by a dense seismic array.GEOPHYSICAL JOURNAL INTERNATIONAL,235(2).

Deng, Yufeng,et al."Structure of the Gonghe Sedimentary Basin in the northeastern Tibetan Plateau: evidence from teleseismic P waves recorded by a dense seismic array".GEOPHYSICAL JOURNAL INTERNATIONAL 235.2(2023).