首页|Evaluation of 3D crustal seismic velocity models in southwest China:Model performance,limitation,and prospects

Evaluation of 3D crustal seismic velocity models in southwest China:Model performance,limitation,and prospects

扫码查看
原文链接
  • 万方数据
  • 维普
Southwest China is a tectonically and seismically active region,witnessing strong deformation due to the collision between the Indian and Eurasian plates.Constraining the subsurface velocity structure of this region is thus important in understanding the tectonics and geodynamic processes of continental collision and in mitigating seismic hazards.Numerous studies have provided various 3D seismic velocity models in southwest China.However,discrepancies exist among these models,and less effort has been made to quantify the reliability and accuracy of these existing velocity models.In this study,we use regional 3D waveform simulation to evaluate the performance of various regional crustal 3D velocity models in reproducing observed seismograms.We particularly focus on two recent earthquake sequence in the region,the 2021 Yunnan Yangbi Ms6.4 earthquake sequence and the 2022 Sichuan Luding Ms6.8 earthquake sequence.The tested 3D velocity models include the Southwest China Community Velocity model V1.0,the Unified Seismic Tomography Models for Continental China Lithosphere V2.0,the adjoint full waveform tomography model of the crustal and upper mantle beneath Eastern Tibetan Plateau,and the shallow seismic structure model beneath continental China.Our results show that the tested 3D velocity models generally capture well long-period(＜0.2 Hz)waveforms,indicating that the 3D models adequately resolve overall large-scale subsurface structures.However,the 3D synthetics show discrepancies in higher frequencies(0.05-0.3 Hz)and the performance of the 3D velocity models varies from region to region,suggesting that smaller scale heterogeneities are not well constrained.Including shallow velocity structures(＜10 km)can improve the waveform fitting,emphasizing the importance of incorporating shallow structures in waveform modeling.The full-waveform tomography model shows a slighter better performance than the other models,especially for the body-waves,highlighting the advantages of full-waveform method in achieving sub-wavelength resolution despite the usage of very long-period waveforms.In light of these comparison results of model performance,we identify the advantages and limitations of different seismic tomography models and methods,and we propose to incorporate different tomography methods and datasets to better constrain subsurface structures.While our target region in this study is southwest China,the analysis that we have conducted can be applied to other regions of various scales and tectonic settings for quantitative seismic model evaluation.

Southwest ChinaSeismic tomography modelsShallow structuresWaveform simulationModel evaluation

Xin WANG、Ling CHEN、Qi-Fu CHEN

展开 >

Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China

College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China

State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China

National Key R&D Program of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaKey Research Program of the Institute of Geology and Geophysics,Chinese Academy of Sciences

2022 YFF08026009195820942288201IGGCAS-201904

2024

10.1007/s11430-023-1215-1

中国科学:地球科学(英文版)
中国科学院

中国科学:地球科学(英文版)

影响因子：1.002
ISSN：1674-7313
年,卷(期)：2024.67(2)
  • 35