Fault model of the 2017 Jiuzhaigou Mw 6.5 earthquake estimated from coseismic deformation observed using Global Positioning System and Interferometric Synthetic Aperture Radar data

Abstract On August 8, 2017, the Jiuzhaigou Mw 6.5 earthquake occurred in Sichuan province, southwestern China, along the eastern margin of the Tibetan Plateau. The epicenter is surrounded by the Minjiang, Huya, and Tazang Faults. As the seismic activity and tectonics are very complicated, there is c...

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Main Authors: Zhaosheng Nie, Di-Jin Wang, Zhige Jia, Pengfei Yu, Liangfa Li
Format: Article
Language:English
Published: SpringerOpen 2018-04-01
Series:Earth, Planets and Space
Subjects:
Online Access:http://link.springer.com/article/10.1186/s40623-018-0826-4
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author Zhaosheng Nie
Di-Jin Wang
Zhige Jia
Pengfei Yu
Liangfa Li
author_facet Zhaosheng Nie
Di-Jin Wang
Zhige Jia
Pengfei Yu
Liangfa Li
author_sort Zhaosheng Nie
collection DOAJ
description Abstract On August 8, 2017, the Jiuzhaigou Mw 6.5 earthquake occurred in Sichuan province, southwestern China, along the eastern margin of the Tibetan Plateau. The epicenter is surrounded by the Minjiang, Huya, and Tazang Faults. As the seismic activity and tectonics are very complicated, there is controversy regarding the accurate location of the epicenter and the seismic fault of the Jiuzhaigou earthquake. To investigate these aspects, first, the coseismic deformation field was derived from Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) measurements. Second, the fault geometry, coseismic slip model, and Coulomb stress changes around the seismic region were calculated using a homogeneous elastic half-space model. The coseismic deformation field derived from InSAR measurements shows that this event was mainly dominated by a left-lateral strike-slip fault. The maximal and minimal displacements were approximately 0.15 m and − 0.21 m, respectively, along line-of-sight observation. The whole deformation field follows a northwest-trending direction and is mainly concentrated west of the fault. The coseismic slip is 28 km along the strike and 18 km along the dip. It is dominated by a left-lateral strike-slip fault. The average and maximal fault slip is 0.18 and 0.85 m, respectively. The rupture did not fully reach the ground surface. The focal mechanism derived from GPS and InSAR data is consistent with the kinematics and geometry of the Huya Fault. Therefore, we conclude that the northern section or the Shuzheng segment of the Huya Fault is the seismogenic fault. The maximal fault slip is located at 33.25°N and 103.82°E at a depth of ~ 11 km, and the release moment is approximately 6.635 × 1018 Nm, corresponding to a magnitude of Mw 6.49, which is consistent with results reported by the US Geological Survey, Global Centroid Moment Tensor, and other researchers. The coseismic Coulomb stress changes enhanced the stress on the northwest and southeast edges of the northern extension of the Huya Fault. Seismic risks cannot be ignored in the future although aftershocks are fewer in number in these regions.
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spelling doaj.art-7b847d1287e4494aa9a015200a8011392022-12-22T00:54:25ZengSpringerOpenEarth, Planets and Space1880-59812018-04-0170111210.1186/s40623-018-0826-4Fault model of the 2017 Jiuzhaigou Mw 6.5 earthquake estimated from coseismic deformation observed using Global Positioning System and Interferometric Synthetic Aperture Radar dataZhaosheng Nie0Di-Jin Wang1Zhige Jia2Pengfei Yu3Liangfa Li4Key Laboratory of Earthquake Geodesy, Institute of Seismology, Chinese Earthquake AdministrationKey Laboratory of Earthquake Geodesy, Institute of Seismology, Chinese Earthquake AdministrationKey Laboratory of Earthquake Geodesy, Institute of Seismology, Chinese Earthquake AdministrationKey Laboratory of Earthquake Geodesy, Institute of Seismology, Chinese Earthquake AdministrationKey Laboratory of Earthquake Geodesy, Institute of Seismology, Chinese Earthquake AdministrationAbstract On August 8, 2017, the Jiuzhaigou Mw 6.5 earthquake occurred in Sichuan province, southwestern China, along the eastern margin of the Tibetan Plateau. The epicenter is surrounded by the Minjiang, Huya, and Tazang Faults. As the seismic activity and tectonics are very complicated, there is controversy regarding the accurate location of the epicenter and the seismic fault of the Jiuzhaigou earthquake. To investigate these aspects, first, the coseismic deformation field was derived from Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) measurements. Second, the fault geometry, coseismic slip model, and Coulomb stress changes around the seismic region were calculated using a homogeneous elastic half-space model. The coseismic deformation field derived from InSAR measurements shows that this event was mainly dominated by a left-lateral strike-slip fault. The maximal and minimal displacements were approximately 0.15 m and − 0.21 m, respectively, along line-of-sight observation. The whole deformation field follows a northwest-trending direction and is mainly concentrated west of the fault. The coseismic slip is 28 km along the strike and 18 km along the dip. It is dominated by a left-lateral strike-slip fault. The average and maximal fault slip is 0.18 and 0.85 m, respectively. The rupture did not fully reach the ground surface. The focal mechanism derived from GPS and InSAR data is consistent with the kinematics and geometry of the Huya Fault. Therefore, we conclude that the northern section or the Shuzheng segment of the Huya Fault is the seismogenic fault. The maximal fault slip is located at 33.25°N and 103.82°E at a depth of ~ 11 km, and the release moment is approximately 6.635 × 1018 Nm, corresponding to a magnitude of Mw 6.49, which is consistent with results reported by the US Geological Survey, Global Centroid Moment Tensor, and other researchers. The coseismic Coulomb stress changes enhanced the stress on the northwest and southeast edges of the northern extension of the Huya Fault. Seismic risks cannot be ignored in the future although aftershocks are fewer in number in these regions.http://link.springer.com/article/10.1186/s40623-018-0826-42017 Jiuzhaigou earthquakeCoseismic slip modelGPSInSARCoulomb stress change
spellingShingle Zhaosheng Nie
Di-Jin Wang
Zhige Jia
Pengfei Yu
Liangfa Li
Fault model of the 2017 Jiuzhaigou Mw 6.5 earthquake estimated from coseismic deformation observed using Global Positioning System and Interferometric Synthetic Aperture Radar data
Earth, Planets and Space
2017 Jiuzhaigou earthquake
Coseismic slip model
GPS
InSAR
Coulomb stress change
title Fault model of the 2017 Jiuzhaigou Mw 6.5 earthquake estimated from coseismic deformation observed using Global Positioning System and Interferometric Synthetic Aperture Radar data
title_full Fault model of the 2017 Jiuzhaigou Mw 6.5 earthquake estimated from coseismic deformation observed using Global Positioning System and Interferometric Synthetic Aperture Radar data
title_fullStr Fault model of the 2017 Jiuzhaigou Mw 6.5 earthquake estimated from coseismic deformation observed using Global Positioning System and Interferometric Synthetic Aperture Radar data
title_full_unstemmed Fault model of the 2017 Jiuzhaigou Mw 6.5 earthquake estimated from coseismic deformation observed using Global Positioning System and Interferometric Synthetic Aperture Radar data
title_short Fault model of the 2017 Jiuzhaigou Mw 6.5 earthquake estimated from coseismic deformation observed using Global Positioning System and Interferometric Synthetic Aperture Radar data
title_sort fault model of the 2017 jiuzhaigou mw 6 5 earthquake estimated from coseismic deformation observed using global positioning system and interferometric synthetic aperture radar data
topic 2017 Jiuzhaigou earthquake
Coseismic slip model
GPS
InSAR
Coulomb stress change
url http://link.springer.com/article/10.1186/s40623-018-0826-4
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