[1]PANG Weidong,YANG Runhai,XU Yaji,et al.Study on the Crustal Wave Velocity Variation around the 2014 Ludian MS6.5 Earthquake Area by Background Noise Autocorrelation Function[J].Journal of Seismological Research,2017,40(03):491-501.
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
40
Number of periods:
2017 03
Page number:
491-501
Column:
自投稿专栏
Public date:
2017-07-20
- Title:
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Study on the Crustal Wave Velocity Variation around the 2014 Ludian MS6.5 Earthquake Area by Background Noise Autocorrelation Function
- Author(s):
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PANG Weidong; YANG Runhai; XU Yaji; SHEN Yahong
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(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)
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- Keywords:
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the Ludian earthquake; background noise; autocorrelation; relative wave velocity variation
- CLC:
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P315.3
- DOI:
-
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- Abstract:
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Firstly,using three component seismic background noise data recorded by 5 seismic stations located around the Ludian MS6.5 earthquake area from Jan.2013 to Dec.2015,we calculated autocorrelation Green function in different frequency.Secondly,we obtained the “Current Green function” by the stacking of autocorrelation Green function by sliding window with 30 days as window and 1 day as step and the “Referent Green function” by the stacking of autocorrelation Green function in the whole study time.Finally,based on “current Green function” and “referent Green function”,we calculated the relative wave velocity variation of each station by Moving Window Cross Spectrum(MWCS)and Stretching technology to analyze the relative variation characteristics of wave velocity before and after the Ludian MS6.5 earthquake.The results show that the variation of relative wave velocity by two methods was consistent well.The sensitive depth of the measured relative wave velocity in 0.2~0.5 Hz to the medium is about 4 km,and the wave velocity have a strong annual variation trend.After the Ludian earthquake and the Yongshan earthquake,the coseismic wave velocity variation of stations is significant,which showed as a significant decrease,and the wave velocity of Zhaotong(ZAT)and Yanjin(YAJ)Stations decreased reached 0.06%.The wave velocity variation in the whole study period shows the overall characteristics of “disturbance-earthquake-decrease-recovery and uplift-earthquake-decrease-recovery-disturbance”.We didn't observe obvious wave velocity changes,however,some seasonal variation characteristics are shown in the frequency of 0.5~1 Hz measuring results.