Yu, S.; Su, X. A Crustal Deformation Pattern on the Northeastern Margin of the Tibetan Plateau Derived from GPS Observations. Remote Sens.2023, 15, 2905.
Yu, S.; Su, X. A Crustal Deformation Pattern on the Northeastern Margin of the Tibetan Plateau Derived from GPS Observations. Remote Sens. 2023, 15, 2905.
Yu, S.; Su, X. A Crustal Deformation Pattern on the Northeastern Margin of the Tibetan Plateau Derived from GPS Observations. Remote Sens.2023, 15, 2905.
Yu, S.; Su, X. A Crustal Deformation Pattern on the Northeastern Margin of the Tibetan Plateau Derived from GPS Observations. Remote Sens. 2023, 15, 2905.
Abstract
Northeastern margin is a natural experimental field for studying crustal extrusion and expansion mechanism. Accurate crustal deformation pattern is a key point in the analysis of regional deformation mechanism and seismic hazard research and judgment. In this paper, the present-day GPS velocity field on the northeastern margin of the Tibetan Plateau was obtained from encrypted GPS observations around the Haiyuan-Liupanshan fault zone, combined with GPS observations on the northeastern margin of the Tibetan Plateau from 2010 to 2020. Firstly, we divided the study area into three relatively independent blocks: ORDOS block, Alxa block and Lanzhou block; secondly, the accurate fault distribution of the Haiyuan-Liupanshan fault zone was taken into account to obtain the optimal inversion model; finally, using the block and fault back-slip dislocation model, the inversion got the slip rate distribution, locking depth and slip deficit rate of each fault. The results indicate that the Laohushan Fault and Haiyuan Fault are dominated by left-lateral strike-slip, while the Liupanshan Fault is dominated by thrust dip-slip, and the Guguan-Baoji Fault has both left-lateral strike-slip and thrust dip-slip components. The maximum locking depths of the Laohushan Fault, Haiyuan Fault, Liupanshan Fault and Guguan-Baoji Fault are 5 km, 13 km, 15 km and 10 km respectively, and the locking of Haiyuan Fault is strong in the middle section and weak in the eastern and western section. The Haiyuan Fault is still in the post-earthquake stress adjustment stage. The slip deficit rate decays from 3.6 mm/yr to 1.8 mm/yr from west to east along the fault zone. Combined with geological and historical seismic data, the results suggest that the mid-long term seismic risk in the Liupanshan Fault is high.
Environmental and Earth Sciences, Geophysics and Geology
Copyright:
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