地震研究

利用2007年11月至2010年5月云南测震台网46个台站共31个月的连续测震记录,采用背景噪声瑞利面波层析成像方法得到云南地区不同周期瑞利面波的相速度背景图像; 用滑动时窗得到当前不同时段瑞利面波相速度图像,将当前速度图像减去背景速度图像,得到当前速度扰动图像; 将不同时段的速度扰动图像与云南中强地震作对比研究,发现在该区域中强地震发生前,在10～25 s周期的相速度扰动图像中,川滇菱形块体中段瑞利面波波速都有明显升高现象。

Applying the Rayleigh Wave Tomography method to the processing of the continuous ambient data recorded by 46 broadband sub-stations of the Yunnan Seismological Network from November,2007 to May,2010,we obtain the background image of the phase velocity of the Rayleigh Wave with different periods in Yunnan area. Then,by removing the background phase velocity from the current phase velocity reconstructed by sliding time-window,we obtain the current velocity-perturbation images. Comparing the velocity-perturbation images with the distribution of moderate-strong earthquakes in Yunnan,we find that before moderate-strong earthquakes in the middle part of the Sichuan-Yunan Rhombic Block,Rayleigh-phase velocity increased significantly in the perturbation images of phase-velocity from 10s to 25s.

引言
1 方法与数据处理
2 数据处理结果
3 讨论
4 结论

图1 云南测震台网子台分布图<br/>Fig.1 Location of the stations of the Yunnan digital seismic network

图1 云南测震台网子台分布图
Fig.1 Location of the stations of the Yunnan digital seismic network

图2 云南地区20 s周期相速度分布图(单位:km/s)<br/>Fig.2 Image of 20-second phase velocity in Yunnan area

图2 云南地区20 s周期相速度分布图(单位:km/s)
Fig.2 Image of 20-second phase velocity in Yunnan area

图3 16 s 周期 29个月的相速度扰动图(%)<br/>Fig.3 Images of 16-second velocity perturbation for 29 months

图3 16 s 周期 29个月的相速度扰动图(%)
Fig.3 Images of 16-second velocity perturbation for 29 months

图4 中甸—盐津台站间格林函数随时间变化<br/>Fig.4 The empirical Green's function change with time for station pair ZOD-YaJ

图4 中甸—盐津台站间格林函数随时间变化
Fig.4 The empirical Green's function change with time for station pair ZOD-YaJ

图5 丽江—昭通台站间格林函数随时间变化<br/>Fig.5 The empirical Green's function change with time for station pair LiJ-ZAT

图5 丽江—昭通台站间格林函数随时间变化
Fig.5 The empirical Green's function change with time for station pair LiJ-ZAT

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备注

引言

1 方法与数据处理

2 数据处理结果

3 讨论

4 结论

期刊信息