地震研究

使用云南数字地震台网记录的波形资料,计算了云南鲁甸M_S6.5地震序列的谱振幅相关系数。8月3日19时至8月4日5时,谱振幅相关系数由序列的最小值持续升高至最大值,期间发生了4次4级余震,表明震源机制逐渐趋于一致,4级地震发生在谱振幅相关系数波动相对较大的阶段。其后谱振幅相关系数一直维持在0.82的高值状态,8月17日距离鲁甸地震震中110 km的同一构造区永善发生M_S5.0地震,表明谱振幅相关系数高区域应力水平较高。

Using seismic wave recorded by Yunnan Digital Seismic Network,we calculated the correlation coefficient of spectral amplitude of Ludian M_S6.5 earthquake sequences in Yunnan in 2014. From 19:00 on Aug. 3 to 05:00 on Aug. 4,four times of M_L≥4.0 aftershocks occurred in the period of the correlation coefficient of spectral amplitude raised from minimum to maximum of the earthquake sequence,and the focal mechanism became to be more consistent gradually in this period. Then,the correlation coefficient of spectral amplitude kept at a high state of 0.82. A M_S5.0 earthquake occurred at Yongshan area on Aug. 17,which belongs to the same geological structure with Ludian earthquake and the two epicenters are only 110 km apart. All these indicate that the higher correlation coefficient of spectral amplitude is corresponding to the high level of the stress filed.

引言
1 谱振幅相关分析法
2 地震序列资料及计算结果
3 结论与讨论

图1 昭通台记录的一次地震的波形(a)及其位移谱(b)<br/>Fig.1 Waveform of a earthquake recorded by Zhaotong Station(a),and its displacement spectra(b)

图1 昭通台记录的一次地震的波形(a)及其位移谱(b)
Fig.1 Waveform of a earthquake recorded by Zhaotong Station(a),and its displacement spectra(b)

图2 鲁甸ML≥3.0地震序列和周围台站分布<br/>Fig.2 Distribution of Ludian ML≥3.0 earthquake sequence and their surrounding stations

图2 鲁甸ML≥3.0地震序列和周围台站分布
Fig.2 Distribution of Ludian ML≥3.0 earthquake sequence and their surrounding stations

图3 鲁甸地震序列的相关系数及震级—时间图(a)数据选取自8月3～11日;(b)数据选取自8月3日至9月7日<br/>Fig.3 The correlation coefficient of spectral amplitude and M-t plot of Ludian earthquake sequence(a)data selected from Aug.3 to Aug.11; (b)data selected from Aug.3 to Sep.7

图3 鲁甸地震序列的相关系数及震级—时间图(a)数据选取自8月3～11日;(b)数据选取自8月3日至9月7日
Fig.3 The correlation coefficient of spectral amplitude and M-t plot of Ludian earthquake sequence(a)data selected from Aug.3 to Aug.11; (b)data selected from Aug.3 to Sep.7

陈颙.1978.用震源机制一致性作为描述地震活动性的新参数[J].地球物理学报,21(2):142-159.
崔子健,李志雄,陈章立,等.2012.判别小震群序列类型的新方法研究——谱振幅相关分析法[J].地球物理学报,55(5):1718-1724.
黄浩,付虹.2014.2008年以来滇西地区地震序列的谱振幅相关系数变化特征[J].地震学报,36(4):631-639.
王俊国,刁桂苓.2005.千岛岛弧大震前哈佛大学矩心矩张量(CMT)解一致性的预测意义[J].地震学报,27(2):178-183.
赵英萍,刁桂苓,高景春,等.2004.张北强余震前震源机制解的一致性特征[J].华北地震科学,22(1):1-4.
Atkinson G.M.,Mereu R.F..1992.The shape of ground motion attenuation curves in southeastern Canada[J].Bull.Seismol.Soc.Am.,82(5):2014-2031.
Chael E..1987.Spectral scaling of earthquakes in the Miramichi region of New Brunswick[J].Bull Seismol Soc Am,77(2):347-365.
Lund B.,Böðvarsson R..2002.Correlation of microearthquake body-wave spectral amplitudes[J].Bull.Seismol.Soc.Am.,92(6):2419-2433.
Moya A.,Jorge A..2000.Inversion of source parameters and site effects from strong ground motion records using genetic algorithms[J].Bull.Seismol.Soc.Am.,90(4):977-992.
Wiemer S.,Wyss M..2002.Mapping spatial variability of the frequency-magnitude distribution of earthquakes[J].Advances in Geophysics,45:259-302.

备注

引言

1 谱振幅相关分析法

2 地震序列资料及计算结果

3 结论与讨论

期刊信息