地震研究

在2016年1月21日门源6.4级地震发生以后,利用DB5小波基对该地震震中所在的冷龙岭断裂及其周边地区岩石圈磁场进行了小波分解,分析了各阶小波细节及小波逼近结果,并根据分解结果研究不同深度场源的岩石圈磁场与门源地震的关系。小波分解的结果显示,浅层与中层的磁异常分布不均匀,震中位置位于ΔZ正负值转换区域; 而底层磁异常则相对均匀宽缓,震中附近并无显著分界特征。

After Menyuan MS6.4 earthquake on Jan.21,2016,the lithospheric magnetic field feature of Lenglongling Fault and its adjacent area where the epicenter located has been decomposed by using DB5 wavelet basis,and the wavelet details of each order and wavelet approximation result are also analyzed. Then based on the wavelet decomposition results,we study the relationship of lithospheric magnetic field with earthquake. The wavelet analysis result shows that the distribution of magnetic anomaly in the shallow layer and middle layer is non-uniform. The epicenter located in the transit area of positive and negative value of ΔZ. The magnetic anomaly in the bottom layer is relatively uniform and wide,and the area nearby the epicenter has no obvious boundary characteristic.

引言
1 数据选取
2 岩石圈磁场特征分析
3 磁场特征与门源地震关系的研究
4 结论与讨论

图1 冷龙岭断裂带及周边地区部分流动地磁测点分布<br/>Fig.1 Distribution of part of magnetic survey stations in Lenglongling Fault and its adjacent area

图1 冷龙岭断裂带及周边地区部分流动地磁测点分布
Fig.1 Distribution of part of magnetic survey stations in Lenglongling Fault and its adjacent area

图2 冷龙岭断裂及其周边区域岩石圈磁场ΔX(a)、ΔY(b)、ΔZ(c)分布图(单位:nT)<br/>Fig.2 Distribution of ΔX(a)、ΔY(b)、ΔZ(c) of lithospheric magnetic field in Lenglongling Fault and its adjacent area

图2 冷龙岭断裂及其周边区域岩石圈磁场ΔX(a)、ΔY(b)、ΔZ(c)分布图(单位:nT)
Fig.2 Distribution of ΔX(a)、ΔY(b)、ΔZ(c) of lithospheric magnetic field in Lenglongling Fault and its adjacent area

图3 冷龙岭断裂带及其临近地区岩石圈磁场ΔZ小波分解结果与门源地震(a)1～3阶小波细节;(b)4～6阶小波细节;(c)6阶小波近似;(d)原始图像<br/>Fig.3 Wavelet analysis of the ΔZ of lithospheric magnetic field in Lenglongling Fault and its adjacent area and Menyuan Earthquake (a)wavelet details of degree 1 to 3;(b)wavelet details of degree 4 to 6;(c)wavelet approximation of degree 6;(d)original image

图3 冷龙岭断裂带及其临近地区岩石圈磁场ΔZ小波分解结果与门源地震(a)1～3阶小波细节;(b)4～6阶小波细节;(c)6阶小波近似;(d)原始图像
Fig.3 Wavelet analysis of the ΔZ of lithospheric magnetic field in Lenglongling Fault and its adjacent area and Menyuan Earthquake (a)wavelet details of degree 1 to 3;(b)wavelet details of degree 4 to 6;(c)wavelet approximation of degree 6;(d)original image

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备注

引言

1 数据选取

2 岩石圈磁场特征分析

3 磁场特征与门源地震关系的研究

4 结论与讨论

期刊信息