The slip rate and strong earthquake recurrence interval on the Qianning-Kangding segment of the Xianshuihe fault zone
The slip rate and strong earthquake recurrence interval on the Qianning-Kangding segment of the Xianshuihe fault zone
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DOI：
10.1007/s11589-001-0004-8
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发表时间：
2001-05
影响因子：
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通讯作者：
Rongjun Zhou;Yu-lin He;Zu-zhi Huang;Xiao-gang Li;Tao Yang
中科院分区：
文献类型：
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作者：
Rongjun Zhou;Yu-lin He;Zu-zhi Huang;Xiao-gang Li;Tao Yang
鲜水河断裂带前宁-康定段几何构造较为复杂，由4条次级断裂组成。雅拉河断裂、塞拉哈—康定断裂、泽多塘断裂和磨溪断裂。1725年、1786年和1955年分别发生了3次7.0级以上强震。根据断层地貌和年代学（14C和热发光）研究，本文记录了黔宁-康定段各次断裂晚第四纪的平均水平滑动速率：亚拉河断裂（2.0±0.2）mm/a；塞拉哈-康定断层：（5.5±0.6）mm/a；泽多堂故障：（3.6±0.3）mm/a；磨溪故障：（9.9±0.6）mm/a。历史地震、同震滑动和古地震地表破裂调查结果表明，亚拉河断裂的强震复发间隔为数千年，而塞拉哈-康定断裂和泽多塘断裂的强震复发间隔为230 ~ 350年。在接下来的一百年里，在这些断层上再次发生强震似乎是不可能的。而磨溪断裂带的强震复发周期约为300年。到目前为止，距离上一次1786年发生的7 - 3 / 4级地震已经214年了，因此，该断层现在正在接近下一次强震复发的有利条件。
The geometry of the Qianning-Kangding segment of the Xianshuihe fault zone is quite complex, and it is composed of four secondary-faults,i.e., the Yalahe fault, Selaha-Kangding fault, Zeduotang fault and Moxi fault. On this segment, three strong earthquakes withM≥7.0 occurred in 1725, 1786 and 1955, respectively. Based on a study of fault landform and geochronology (14C and Thermoluminesense), this paper documents the average horizontal slip rates during the late-Quaternary on all the secondary-faults of the Qianning-Kangding segment as follows: Yalahe fault: (2.0±0.2) mm/a; Selaha-Kangding fault: (5.5±0.6) mm/a; Zeduotang fault: (3.6±0.3) mm/a; Moxi fault: (9.9±0.6) mm/a.The results from the investigation of surface ruptures of historical earthquakes, coseismic-slip and paleo-earthquakes show that the strong-earthquake recurrence intervals are thousands of years on the Yalahe fault, and 230 to 350 years on the Selaha-Kangding and Zeduotang faults. In the next one hundred years, the recurrence of a strong-earthquake on these faults appears impossible. However, the strong-earthquake recurrence interval on the Moxi fault is about 300 years. Up to now, it has been 214 years since the last earthquake (magnitude 7¾) occurred in 1786, therefore, this fault is now approaching the condition favorable for the next strong earthquake recurrence.