SEISMOLOGY AND GEOLOGY ›› 2026, Vol. 48 ›› Issue (4): 1035-1051.DOI: 10.3969/j.issn.0253-4967.20250066

• Research paper • Previous Articles     Next Articles

SURFACE DEFORMATION CHARACTERISTICS OF THE 2025 DINGRI MW7.1 EARTHQUAKE DERIVED FROM GF-2 IMAGERY USING OPTICAL IMAGE CORRELATION TECHNIQUE

SU Qiang1)(), PAN Jia-wei1,2,3),*(), LI Hai-bing1,2,3), LIU Fu-cai1,2), Marie-luce Chevalier1,2,3), YANG Shao-hua1,2,3), WU Kun-gang1,4), JIANG Chen-yi1)   

  1. 1) Key Laboratory of Continental Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China
    2) National Field Observation and Research Station(Jiangsu Donghai) for Continental Deep Hole Crustal Activity, Lianyungang 222300, China
    3) State Key Laboratory of Deep Earth and Mineral Exploration, Beijing 100094, China
    4) Key Laboratory of Active Tectonics and Geological Safety, Ministry of Natural Resources, Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China
  • Received:2025-03-14 Revised:2025-04-27 Online:2026-08-20 Published:2026-09-09

基于GF-2影像相关性匹配的2025年 MW7.1 西藏定日地震地表变形特征

苏强1)(), 潘家伟1,2,3),*(), 李海兵1,2,3), 刘富财1,2), Marie-Luce Chevalier1,2,3), 杨少华1,2,3), 吴坤罡1,4), 江晨轶1)   

  1. 1) 中国地质科学院地质研究所, 自然资源部大陆动力学重点实验室, 北京 100037
    2) 江苏东海大陆深孔地壳活动国家野外科学观测研究站, 连云港 222300
    3) 深地探测与矿产勘查全国重点实验室, 北京 100094
    4) 中国地质科学院地质力学研究所, 自然资源部活动构造与地质安全重点实验室, 北京 100081
  • 通讯作者: * 潘家伟, 男, 1983生, 研究员, 主要从事青藏高原活动构造与地震地质研究, E-mail:
  • 作者简介:

    苏强, 男, 2000年生, 现为中国地质科学院地质研究所地质学专业在读硕士研究生, 从事遥感与活动构造相关研究, E-mail:

  • 基金资助:
    中国地质调查局项目(DD20240100703); 科技基础资源调查专项(2021FY100101); 国家自然科学基金(42372274); 国家自然科学基金(42325207); 中国地质科学院地质力学所基本科研业务项目(DZLXJK202413)

Abstract:

Accurate quantification of near-surface coseismic fault-slip distribution is critical for understanding earthquake rupture propagation and fault structural evolution. Traditional field surveys and geodetic methods have inherent limitations in resolving spatially distributed coseismic surface deformation with high precision. In recent years, rapid advances in sub-pixel correlation techniques applied to optical satellite imagery have provided an effective approach for comprehensive and high-resolution quantification of coseismic surface displacements. On 7 January 2025, an MW7.1 earthquake struck Dingri County, Tibet, at a focal depth of 10km, causing significant casualties and economic losses and generating a coseismic surface rupture zone of approximately 35km along the Dingmu Co Fault. Following the event, numerous studies investigated coseismic surface deformation using high-resolution remote sensing interpretation, field surveys, GNSS, and Interferometric Synthetic Aperture Radar(InSAR). However, owing to methodological limitations, the distributed surface deformation associated with the Dingri earthquake has not yet been fully resolved. To further constrain the coseismic surface deformation characteristics of this event, this study uses pre- and post-event Chinese Gaofen-2 (GF-2) optical satellite images with a spatial resolution of 0.81m. Coseismic displacements are quantitatively derived using sub-pixel image correlation implemented in the COSI-Corr software package.

The image correlation results demonstrate that GF-2 imagery has strong capability for quantifying coseismic displacement and clearly reveals an approximately 6km-long coseismic surface rupture segment northeast of Nixia Co. Consistent with this result, field investigations indicate that the area northeast of Nixia Co experienced the largest coseismic surface rupture, with a maximum vertical offset approaching 3m. The rupture traces extracted from image correlation show good overall agreement with those mapped through field surveys and high-resolution unmanned aerial vehicle(UAV)imagery. The north-south displacement field derived from image correlation indicates northward motion of the eastern footwall and southward motion of the western hanging wall, consistent with field observations of coseismic rupture characteristics. In addition, the coseismic displacement vector field clearly reveals oblique slip, with the western hanging wall moving toward the SWW and the eastern footwall moving toward the NEE. Integrated analysis of multi-source datasets indicates that the Dingri earthquake was dominated by normal faulting with a significant sinistral, or left-lateral, strike-slip component.

Based on the image correlation results, horizontal displacement components in the east-west and north-south directions were extracted along the rupture trace using swath profiles. The results indicate that east-west extensional displacement across the Nixia Co segment predominantly ranges from 0.8 to 2.8m, with an average of approximately 2.0m and a maximum of 3.9m. The sinistral strike-slip displacement mainly ranges from 0.4 to 1.6m, with an average of approximately 0.9m and a maximum of 1.9m. Comparative analysis shows that, although the deformation trends derived from image correlation are consistent with field measurements, most field-measured coseismic displacements are systematically smaller than those obtained from image correlation. This discrepancy suggests that the 2025 Dingri earthquake likely produced a certain degree of off-fault deformation. Furthermore, the image correlation results indicate that the ratio of extensional to strike-slip displacement is approximately 2:1 for both average and maximum values. Based on this kinematic relationship, together with fault dip angles derived from inversion results reported in previous studies, the fault slip rake angle of the Dingri earthquake is estimated to range from -69° to -73°.

Key words: optical image correlation, Dingri earthquake, coseismic surface deformation, GF-2, Tibetan plateau

摘要:

准确量化同震断层滑动在近地表的分布特征, 对于认识地震破裂传播过程及断层结构演化至关重要。传统的野外实测和大地测量方法存在难以精确量化分散的区域性同震地表变形的问题。近年来, 光学卫星影像亚像素相关性匹配技术的迅速发展, 为高精度全面量化同震地表位移提供了新的解决方案。2025年1月7日, 西藏定日县发生 MW7.1 强震, 造成了较大的人员伤亡和财产损失, 并沿丁木错断裂形成了长约35km的同震地表破裂带。为精确分析定日地震的同震地表变形特征, 文中利用震前和震后的中国高分二号(GF-2)光学卫星影像, 基于影像相关性匹配技术开展了同震位移定量研究。结果表明, 国产GF-2卫星影像在量化同震位移方面具有出色表现, 清晰地揭示了定日地震在尼辖错东北侧形成的长约6km的同震地表破裂带。影像匹配获得的同震地表变形场与野外调查结果共同揭示, 定日地震是一次伴随左行走滑分量的正断型地震事件, 尼辖错段地表破裂带EW向伸展量的平均值约为2m, 最大达3.9m, SN向左行走滑位移量的平均值约为0.9m, 最大达1.9m。根据伸展量与走滑量的比例关系, 结合断层倾角数据, 估算定日地震的断层滑动角约为-69°~-73°。

关键词: 光学影像相关性匹配, 定日地震, 同震地表变形, 高分二号, 青藏高原