地震研究

2013年云南洱源M_S5.5地震序列不同地震观测台网地震定位结果对比分析^*

李涛¹,付虹^1,姜金钟¹,徐兴倩²

(1.云南省地震局,云南昆明 650224; 2.云南农业大学,云南昆明 650201)

关键词：双差定位; 波形互相关; 云南地震台网; 流动台阵; 洱源地震序列

Comparison of Locations Results for the 2013 Yunnan Eryuan M_S5.5 Earthquake Sequence from Different Seismic Networks

LI Tao¹,FU Hong¹,JIANG Jinzhong¹,XU Xingqian²

(1. Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)(2. Yunnan Agriculture University,Kunming 650201,Yunnan,China)

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参考文献

基于云南地震台网和“喜玛拉雅计划”台阵探测项目流动台阵所记录到的波形资料,分3种情况对2013年云南洱源MS5.5地震进行重新定位:第一种仅利用云南地震台网数据进行定位,第二种仅利用流动台阵数据进行定位,第三种是综合云南地震台网和流动台阵数据,并结合波形互相关双差定位法进行定位。研究结果显示:在水平方向上,这3种情况得到的地震震中优势分布方向大致相同,与乔后—维西断裂NNW走向一致,但后2种情况所得到震中分布更集中,呈现的条带状更明显; 在深度分布方面,后2种情况得到的震源深度比仅用云南地震台网资料进行双差定位得到的深度浅,且更加集中; 在残差方面,结合波形互相关的双差定位法得到的震源位置估算误差在EW向、NS向、UD向最小。这表明台站密度更大,布局更合理,得到的定位结果误差明显降低,无论在水平方向还是深度方向分布都更为集中。

引言
1 地震序列概况
2 资料与速度模型选取
3 洱源序列定位结果
4 结论和讨论

图1 2013年洱源地震序列ML≥0地震M-t图(a),N-t图(b)<br/>Fig.1 M-t diagram(a)and N-t diagram(b) for Eryuan ML≥0 earthquake sequence in 2013

图1 2013年洱源地震序列ML≥0地震M-t图(a),N-t图(b)
Fig.1 M-t diagram(a)and N-t diagram(b) for Eryuan ML≥0 earthquake sequence in 2013

图2 用于重新定位的震中距300 km以内地震台站分布<br/>Fig.2 Distribution of seismic stations with epicenter distance of ≤300 km for relocation

图2 用于重新定位的震中距300 km以内地震台站分布
Fig.2 Distribution of seismic stations with epicenter distance of ≤300 km for relocation

表1 双差定位采用的速度模型<br/>Tab.1 The velocity model used in double-difference location

表1 双差定位采用的速度模型
Tab.1 The velocity model used in double-difference location

图3 云南地震台网资料双差定位前(a)、后(b)震中分布<br/>Fig.3 Epicenter distribution before(a)and after(b)double difference relocation by using data from Yunnan Seismic Network

图3 云南地震台网资料双差定位前(a)、后(b)震中分布
Fig.3 Epicenter distribution before(a)and after(b)double difference relocation by using data from Yunnan Seismic Network

图4 云南地震台网资料双差定位前(a、b)、后(c、d)震源深度分别沿经纬度方向的投影<br/>Fig.4 The focal depth distribution along the latitude and longitude direction before(a,b)and after(c,d)double difference relocation by using data from Yunnan Seismic Network

图4 云南地震台网资料双差定位前(a、b)、后(c、d)震源深度分别沿经纬度方向的投影
Fig.4 The focal depth distribution along the latitude and longitude direction before(a,b)and after(c,d)double difference relocation by using data from Yunnan Seismic Network

图5 云南地震台网资料双差定位前(a)、后(b)震源深度分布柱状图<br/>Fig.5 The histogram of focal depth before(a)and after(b)double-difference relocation by using data from Yunnan Seismic Network

图5 云南地震台网资料双差定位前(a)、后(b)震源深度分布柱状图
Fig.5 The histogram of focal depth before(a)and after(b)double-difference relocation by using data from Yunnan Seismic Network

图6 云南地震台网资料的双差定位结果误差统计<br/>Fig.6 Relocation error statistics of double-difference location result by using the data from Yunnan Seismic Network

图6 云南地震台网资料的双差定位结果误差统计
Fig.6 Relocation error statistics of double-difference location result by using the data from Yunnan Seismic Network

图7 流动台阵资料双差定位前(a)、后(b)震中分布<br/>Fig.7 Epicenter distribution before(a)and after(b)double-difference relocation by using data from flow temporary array

图7 流动台阵资料双差定位前(a)、后(b)震中分布
Fig.7 Epicenter distribution before(a)and after(b)double-difference relocation by using data from flow temporary array

图8 流动台阵资料双差定位前(a、b)、后(c、d)深度分别沿经纬度方向的投影<br/>Fig.8 The focal depth distribution along the latitude and longitude directions before(a,b) and after(c,d)double-difference relocation by using data from flow temporary array

图8 流动台阵资料双差定位前(a、b)、后(c、d)深度分别沿经纬度方向的投影
Fig.8 The focal depth distribution along the latitude and longitude directions before(a,b) and after(c,d)double-difference relocation by using data from flow temporary array

图9 流动台阵资料双差定位前(a)、后(b)震源深度分布柱状图<br/>Fig.9 The histogram of focal depth before(a)and after(b)double-difference relocation by using data of flow temporary array

图9 流动台阵资料双差定位前(a)、后(b)震源深度分布柱状图
Fig.9 The histogram of focal depth before(a)and after(b)double-difference relocation by using data of flow temporary array

图10 流动台阵资料的双差定位结果误差统计<br/>Fig.10 Relocation error statistics of double-difference location result by using the data of flow temporary array

图10 流动台阵资料的双差定位结果误差统计
Fig.10 Relocation error statistics of double-difference location result by using the data of flow temporary array

图11 结合波形互相关双差定位的震中分布图<br/>Fig.11 Epicenter distribution by using doubles difference method combined with waveform cross-correlation technique

图11 结合波形互相关双差定位的震中分布图
Fig.11 Epicenter distribution by using doubles difference method combined with waveform cross-correlation technique

图12 结合波形互相关双差定位的震源深度沿纬度(a)和经度(b)方向的投影<br/>Fig.12 The focal depth projection along altitude(a)and longtitude(b)by doubles difference method combined with waveform cross-correlation technique

图12 结合波形互相关双差定位的震源深度沿纬度(a)和经度(b)方向的投影
Fig.12 The focal depth projection along altitude(a)and longtitude(b)by doubles difference method combined with waveform cross-correlation technique