中国大陆及其分区余震序列b值的统计特征分析

Analysis on statistical characteristics of b values of aftershock series in China continent and its subregions

该文研究1966—1999年中国大陆及其分区的浅源主震型序列余震强度分布b值的统计特征。对于中国大陆整体而言,88个震例样本的b值平均为0.73±0.19。进一步将中国大陆划分为四个分区:西北地区(29个震例样本)、西南地区(29个震例样本)、华北地区(25个震例样本)和华南地区(5个震例样本)。选取样本多的前三者作为本文研究区。它们的b值平均()分别为0.62±0.17、0.86±0.17和0.69±0.14。根据平均值之间差异显著性的Z检验,研究分区之间b值平均在90%以上的显著性水平上的差别是明显的。该文还对比研究了不同板块构造背景的中国大陆(88个震例样本,=0.73±0.19)、美国南加洲(39个震例样本,=1.06±0.26)和日本地区(57个震例样本,=0.85±0.26)之间,浅源余震序列b值平均的差异显著性。

This paper investigated the statistical characteristics of b values of aftershock series in China continent and its subregions during 1966-1999. For the whole China continent, the mean of b values is 0. 73±0.19 , based on 88 samples of aftershock series. Further the China continent is divided into four sub-regions： Northwestern region （29 samples）, Southwestern region （29 samples）, North China region （25 samples） and Southeast region （5 samples）. We choose the front three regions with more samples as studied ones in this paper, its means of b values （b^-）are 0. 62±0.17, 0. 86±0.17 and 0. 69±0.14 respectively. According to the Z-test on the differences of two means, the difference among the means of b values for the sub-regions is obviously at 90% or more significant level. This paper also investigated the significant difference among the means of b values of aftershock series for shallow earthquakes in China continent （b^-=0.73±0.19）, South California of USA （b^-=1. 06±0.26） and Japan region （b^-=0. 85±0. 26）.