[1]FU Hong,HONG Min,WANG Guangming,et al.Common Characteristics and Application Research on Periodic Anomaly before Strong Earthquakes in Yunnan Province[J].Journal of Seismological Research,2020,43(02):241-252.
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
43
Number of periods:
2020 02
Page number:
241-252
Column:
Public date:
2020-06-10
- Title:
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Common Characteristics and Application Research on Periodic Anomaly before Strong Earthquakes in Yunnan Province
- Author(s):
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FU Hong1; HONG Min1; WANG Guangming1; HU Xiaojing1; LI Xiang2; LI Zhirong1; LIU Zifeng1
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(1.Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)(2.Earthquake Prevention and Mitigation Office,Jiangchuan 652600,Yunnan,China)
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- Keywords:
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Yunnan strong Earthquake; anomaly sharacteristics; rorecast criterion; anomaly mechanism
- CLC:
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P315.72
- DOI:
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- Abstract:
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Based on comprehensive analysis of the geophysical observation data of seismicity,deformation,underground fluid,and GNSS in a few specific stations before the M≥6.8 earthquakes in Yunnan region,we conclude that since 1900,before occurrence of 86% M≥6.8 earthquakes,there was a seismic quiescence of M>5 earthquakes,which last 7 to 14 years,in areas within 150 km of epicenter.After the quiescence,a moderate earthquake usually disturbed the quiet period 3~4 years before the occurrence of the coming strong event,then another quiet period continued until the main shock occurs.After occurring of a few strong earthquakes,years-quiet-period of moderate earthquakes lasted many years,while moderates earthquake clustered and belted 1~3 years before the main shock.Since 1971,in the 2°×2° epicenter zone or in the strong epicenter zone,frequentness of M>4 earthquakes have increased abruptly and b value has decreased from a high value to a low value,1~2 years before all the M>6.8 earthquakes.Nearly one year before the main earthquake,in specific stations,the deformation and fluid observation data anomalies occurred distinctly,also quasi synchronous mutation anomalies in 70 days,among them 1~2 changes are the largest values in the past 10 years.In 2014,a significant compression enhancement in the vicinity of the epicenter was observed just one month before the Ludian MS6.5 and Jinggu MS6.6 earthquakes.Furthermore,from the occurrence of the Ludian MS6.5 earthquake to the end of 2019,there was no significant compression enhancement in the Yunnan region.Based on the abnormal characteristics before strong earthquakes,the medium and short term prediction criteria of strong earthquakes in Yunnan region are constructed.Finally,the possible mechanism of some observation phenomena is discussed.