2010年4月14日青海玉树7.1级地震前震中附近地区小震活动的周、月频次分布特征

Distribution characteristics of the month-scale and week-scalenumbers for small earthquakes around the epicenter prior to theApril 14,2010 Yushu earthquake with M_s7.1

根据Kolmogorov-Smirnov分布检验法,利用2000年以来1.7≤ML≤2.9地震目录,对2010年4月14日青海玉树MS7.1前震中附近地区2000年以来地震活动的月频次和2007年7月以来地震活动的周频次分布进行了检验。结果表明,地震活动周频次和月频次都不符合泊松分布和正态分布,但周、月频次累积次数的对数与周、月频次之间呈线性关系,类似于G-R关系。分析了周、月频次的标准差σ、CV值、偏度Sk、峰度Ku和bm值等参数随时间的变化,发现在2010年4月14日青海玉树地震前,这些参数都出现了不同程度的异常变化,其中周频次的分布参数随时间的变化似乎呈现出了某种周期性特征。

The Kolmogorov-Smirnov test is adopted to test the distribution of the month-scale number since 2000 and the week-scale number since 2007 by using the earthquakes of 1.7≤ML ≤2.9 occurring around the epicenter prior to the April 14, 2010 Yushu, Qinghai Province earthquake with Ms7.1. The results show that the weekly number and the monthly number agree with neither the normal distribution nor the Possion distribution. And the relationship between the accumulative frequency of the weekly and monthly numbers and the weekly and monthly numbers resembles the Gutenberg-Richter law. Analyzing the temporal changes of the parameters, such as the standard deviation σ, Cvvalue, skewness Sk, kurtosis Kuand bm value, of the weekly and monthly numbers, we find that these parameters changed obviously prior to the April 14, 2010 Yushu, Q to change inghai Province earthquake of Ms7.1, and the parameters for the weekly number seem in a periodic way