地震科学进展 (Jan 2024)
The MW≥6.5 strong earthquake events since 1990 around the Tibetan Plateau and control-earthquake effect of active tectonic system
Abstract
It is of great scientific significance for regional seismic prevention and disaster mitigation to understand the characteristics and future trends of strong earthquakes related with the active continental collision-extrusion tectonic system in the Tibetan Plateau. The characteristics of MW≥6.5 strong earthquakes since 1990 and the earthquake-controlling phenomena of the continental collision-extrusion tectonic system in the Tibetan Plateau are comprehensively analyzed. The results indicate that the Tibetan Plateau has been in the period of slow release of seismic energy recently, but may be approaching the next period of rapid release. The“multi-level extrusion-rotation active tectonic system”in the continental collision-extrusion tectonic system of the Tibetan Plateau plays a major role in controlling this strong earthquakes process. In particular, the Bayan Hara extrusion tectonic unit shows the most significant strong seismic activity process in this tectonic system. The results of comprehensive study suggest that the earthquake-controlling effect of active tectonic system should be fully recognized in the analysis of activity trend and hazard of regional strong earthquake, which is helpful to scientifically judge the space-time migration process and the most likely location of strong earthquakes in the future. In the process of the current strong earthquake activity, the strong earthquake activity trend of the“multi-level extrusion-rotation active tectonic deformation system”in the Tibetan Plateau will continue in future. In particular, more attention should be paid to the future strong earthquake hazard of three large left-lateral strike-slip fault zones which constitute the boundary of extrusion blocks in the“multi-level extrusion-rotation active tectonic deformation system”, including Altyn-Qilian-Haiyuan fault system, East Kunlun fault zone and Xianshuihe-Xiaojiang fault zone.
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