青藏高原东南缘活动断裂的地震应变能释放系统研究

Seismic strain energy release of active faults in the southeastern margin of the Qinghai­Tibetan Plateau

摘要:

本文以青藏高原东南缘为研究区域，利用G-R震级能量经验公式和Benioff地震应变能释放曲线，对该区域内1500a以来的历史地震应变能释放进行了系统研究。文中给出了各断裂带和断块区的地震应变能释放周期表及相应的地震活动性分析。分析发现研究区域地震应变能的释放具有东强西弱，南强北弱的特征，整体上各断层断块区的历史地震应变能释放符合准周期模式，某些断层和断块区上的地震周期具有某种程度的同步现象。青藏高原东南缘现今处于大释放期，地震的活动性不能忽视。对局部地区的研究结果显示，安宁河-则木河断裂带、小江断裂带的地震活动性较强，对于这些地区应重点跟踪研究。

Abstract:

Using the methods of the Gutenberg magnitude energy experience formula and the Benioff seismic strain energy release curve，we make a systematic study on seismic strain energy release of historical earthquakes within the southeastern margin of the Qinghai-Tibetan Plateau since 1500. The paper provides a periodic table of the earthquake strain energy release in the fault zone and the fault block region. The study shows that seismic strain energy release is strong in the east and south，and weak in the west and north. The overall seismic strain energy release of the Yushu-Xianshuihe-Xiaojiang fault system is consistent with the quasi periodic pattern. The earthquake cycle of some faults and broken blocks has some synchronization phenomena. The risk could not be ignored in the current period of the large release period of the southeastern margin of the Qinghai-Tibetan Plateau. Local analysis results show that seismic risk is very high on the Anninghe river-Zemuhe river fault and Xiaojiang faults. These dangerous zones need follow-up researches. In the future，it is necessary to combine different research methods to improve the reliability of seismic risk assessment.