Abstract
The Haiyuan fault zone is an important tectonic boundary and strong seismic activity belt in northeastern Tibet, but no major earthquake has occurred in the past ∼100 years, since the Haiyuan M8.5 event in 1920. The current state of strain accumulation and seismic potential along the fault zone have attracted significant attention. In this study, we obtained the interseismic deformation field along the Haiyuan fault zone using Envisat/ASAR data in the period 2003–2010, and inverted fault kinematic parameters including the long-term slip rate, locking degree and slip deficit distribution based on InSAR and GPS individually and jointly. The results show that there is near-surface creep in the Laohushan segment of about 19 km. The locking degree changes significantly along the strike with the western part reaching 17 km and the eastern part of 3–7 km. The long-term slip rate gradually decreases from west 4.7 mm/yr to east 2.0 mm/yr. As such, there is large strain accumulation along the western part of the fault and shallow creep along the Laohushan segment; while in the eastern section, the degree of strain accumulation is low, which suggests the rupture segments of the 1920 earthquake may have been not completely relocked.
Highlights
IntroductionLocated on the northeastern margin of the Qinghai-Tibet Plateau, the Haiyuan fault zone is a boundary fault of the stable Alaxan block, the stable Ordos block, and active
Analysis of high-density cross-fault deformation rate profiles on the Laohushan segment indicates a creep length of 19 km
Using the interferometric synthetic aperture radar (InSAR) deformation rate from the Maomaoshan segment to the middle part of the 1920 rupture segment, combined with global positioning system (GPS) observations, we obtained the fine slip rate and locking degree distribution characteristics of Haiyuan fault zone based on the screw dislocation model and the threedimensional back-slip model, respectively
Summary
Located on the northeastern margin of the Qinghai-Tibet Plateau, the Haiyuan fault zone is a boundary fault of the stable Alaxan block, the stable Ordos block, and active. Tibet (Figure 1); it is the most significant regional fault zone for tectonic deformation and strong earthquake activity. The fault zone is characterised by large left-lateral strike-slip and is bounded by the Liupanshan fault to the east and the northern margin fault of the Qilian Mountains to the west. It consists of several segments, including (from west to east) the Lenglongling (LLL), Jinqianghe (JQH), Maomaoshan (MMS), Laohushan (LHS)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
