华南地震

利用非线性定位方法NLLoc，对22次人工定点爆破事件和88次福建仙游震群序列M≥1.5级地震事件进行重新定位，并与福建台网日常定位方法进行对比，讨论了NLLoc方法在台网日常业务应用中的可行性。研究结果表明，NLLoc算法无论是人工爆破还是天然地震，其定位结果在发震时刻误差、震中误差和震源深度误差等方面都优于现有定位方法结果，尤其是在震源深度确定方面NLLoc算法优势明显。该方法定位仙游序列活动初期深度较浅与CAP反演2012年4月15日ML4.1级地震的震源深度一致，地震序列活动中后期深度均值略小于理论估值；而正式目录的地震序列活动初期深度较深，震源深度差值较大，地震序列活动中期深度均值大于理论估值。NLLoc方法可用于台网日常地震定位，且有助于更好地解决震源深度测定问题，提高地震定位精度。

By using the nonlinear location method NLLoc，the paper relocated 22 explosion events and the 88 events of Xianyou earthquake swarm sequence with M≥1.5 in Fujian，compared with the daily location methods of Fujian network，and discussed the feasibility of the NLLoc method in the daily application of the network. The results show that the NLLoc method is superior to the common location methods in terms of origin time error，epicenter error and depth error，and especially the NLLoc algorithm has obvious advantages in determining the focal depth. The initial depth of Xianyou sequence activity is shallow，which is consistent with the depth of the event ML 4.1 retrieved by CAP occurred On April 15th，2012，and the average depth of the seismic sequence activity in the middle and late periods is slightly smaller than the theoretical estimation. While the seismic sequence activity in the official catalogue has a deeper initial depth and a large difference in focal depth，and the average mid-term depth of seismic sequence activity is greater than the theoretical estimation.In summary，the NLLoc method can be used for daily earthquake location of the network，which is better to solve the problem of focal depth measurement and expected to improve seismic location accuracy.

引言
1 定位方法简介
2 研究使用数据情况
3 定位结果分析
4 讨论
5 结语

表1 华南模型
Table 1 South China model

图1 八叉树搜索采样单元(http://alomax.free.fr/nlloc/)<br/>Fig.1 Oct-tree searching method sampling cell

图1 八叉树搜索采样单元(http://alomax.free.fr/nlloc/)
Fig.1 Oct-tree searching method sampling cell

图2 NonLinLoc主程序流程图<br/>Fig.2 The flow chart of NonLinLoc main program

图2 NonLinLoc主程序流程图
Fig.2 The flow chart of NonLinLoc main program

表2 22次人工爆破信息<br/>Table 2 The catalogs of 22 explosions

表2 22次人工爆破信息
Table 2 The catalogs of 22 explosions

图3 5种定位方法的震中位置图<br/>Fig.3 Epicenter location maps of the 5 location methods

图3 5种定位方法的震中位置图
Fig.3 Epicenter location maps of the 5 location methods

表3 震中误差值(单位:km)<br/>Table 3 Errors of the located epicenters by 5 location methods (unit:km)

表3 震中误差值(单位:km)
Table 3 Errors of the located epicenters by 5 location methods (unit:km)

图4 发震时刻误差图<br/>Fig.4 Errors map of the origin time

图4 发震时刻误差图
Fig.4 Errors map of the origin time

图5 深度误差对比图<br/>Fig.5 Comparison of the depth errors

图5 深度误差对比图
Fig.5 Comparison of the depth errors

图6 福建仙游序列M≥1.5级M-t图<br/>Fig.6 M-t diagram of Xianyou earthquake sequence with M≥1.5

图6 福建仙游序列M≥1.5级M-t图
Fig.6 M-t diagram of Xianyou earthquake sequence with M≥1.5

图7 仙游震群序列M≥1.5空间分布<br/>Fig.7 Distribution map of Xianyou earthquake swarm sequence with M≥1.5

图7 仙游震群序列M≥1.5空间分布
Fig.7 Distribution map of Xianyou earthquake swarm sequence with M≥1.5

图8 福建仙游震群序列M≥1.5震中误差和发震时刻误差图<br/>Fig.8 The epicenter error and origin time error of Xianyou earthquake swarm sequence with M≥1.5 in Fujian

图8 福建仙游震群序列M≥1.5震中误差和发震时刻误差图
Fig.8 The epicenter error and origin time error of Xianyou earthquake swarm sequence with M≥1.5 in Fujian

表4 深度均值和标准差(单位:km)<br/>Table 4 the mean and standard deviation of depth (unit:km)

表4 深度均值和标准差(单位:km)
Table 4 the mean and standard deviation of depth (unit:km)

图9 仙游地震序列M≥1.5深度时序图<br/>Fig.9 The depth sequence diagram of Xianyou earthquake swarm sequence with M≥1.5

图9 仙游地震序列M≥1.5深度时序图
Fig.9 The depth sequence diagram of Xianyou earthquake swarm sequence with M≥1.5

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备注

引言

1 定位方法简介

2 研究使用数据情况

3 定位结果分析

4 讨论

5 结语

期刊信息