滇西北地区M≥5.0地震地震学短期预报指标及其预报效能研究

英文篇名：Study on Seismological Short-term Prediction Indexes of M≥5.0 Earthquakes in Northwest Yunnan and Their Prediction Efficiency
中文刊名：地震研究
英文刊名：Journal of Seismological Research
作者：李丽清 ; 李群 ; 和国文
英文作者：LI Li-qing LI Qun HE Guo-wen(Earthquake Administration of Lijiang City ; Lijiang 674100 ; Yunnan ; China)
中文关键词：短期预报 ; 地震学指标 ; 预报效能 ; 滇西北地区
英文关键词：short-term prediction ; seismology index ; prediction efficiency ; Northwest Yunnan
出版日期：2006-04-30
机构：云南省丽江市地震局,云南省丽江市地震局,云南省丽江市地震局丽江674100,丽江674100,丽江674100
年：2006
期：02
出版单位：地震研究

摘要

在滇西北地区(25°~28°N,99°~101.5°E)用不同的统计窗长和滑动步长,对当前常用的地震学参数进行分析研究,最终确定了6个预报指标:频度N、缺震、能量E、断层总面积ΣE、空间集中度C值、地震活动度S值。这6项指标对滇西北地区及周边区域1990年发生的M≥5.0地震有较好的短期映震能力,但丽江7级地震前,6个指标只有缺震出现了明显异常,达到预报指标,其余5个指标都无异常显示。这种结果一方面说明6项指标对6级左右地震有较好的对应关系,但对6.7级以上地震没有控制能力;另一方面也说明,丽江7.0级地震最显著的特征是短期阶段孕震区中小地震活动异常平静。因此,仅仅依靠地震学指标实现短临预报是不够的,还应结合其它方法和手段。
Through analyzing the seismological parameters in common use at present with different windows and slipping steps in Northwest Yunnan(25°-28°N.,99°-101.5°E),we determine 6 prediction indexes(frequency N,earthquake absence M,energy E,total fault area ∑E,spatial centralization C and seismicity S),and study their prediction ability.The result shows that the 6 indexes are effective for the short-term prediction of the earthquake with M≥5.0 in the research area in 1990.However,before the Lijiang M7.0 earthquake,only earthquake absence index appeared anomalous obviously,other 5 indexes hadn't shown anomaly.It reveals:(1) the 6 indexes are effective for the earthquakes with magnitude around 6 but not for the ones with magnitude over 6.7;(2) one of the most notable anomaly features before the Lijiang M7.0 earthquake is the calmness of small and moderate earthquakes in the seismogenic area.Therefore,it is not enough only relying on seismological indexes to give short-time earthquake prediction,and some other prediction approaches must be combined with.

引文

[1]陈立德,付虹.地震预报基础与研究[M].北京:地震出版社,2003.
[2]国家地震局监测预报司.地震学分析预报方法程式指南[M].北京:地震出版社,1990.