[1]WANG Guangming,FU Hong,KONG Deyu,et al.Study of Variation Characteristics of b Value Before M≥5.0 Earthquakes in the Western Region of Yunnan[J].Journal of Seismological Research,2020,43(02):363-374.
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
43
Number of periods:
2020 02
Page number:
363-374
Column:
Public date:
2020-06-10
- Title:
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Study of Variation Characteristics of b Value Before M≥5.0 Earthquakes in the Western Region of Yunnan
- Author(s):
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WANG Guangming; FU Hong; KONG Deyu; LI Yongli
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(Yunan Earthquake Agency,Kunming 650224,Yunan,China)
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- Keywords:
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b value; western region of Yunnan; Yingjiang earthquake; earthquake precursor
- CLC:
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P315.72
- DOI:
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- Abstract:
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We use both complete earthquake catalog and de-aftershock catalog to conduct the spatio-temporal scanning of b value in the western region of Yunnan province by using the maximum likelihood method to search for the spatio-temporal variation characteristics of b value before M≥5.0 earthquakes in this region.The temporal scanning results show that there is no significant difference in the overall trend of the two seismic catalogs,while the spatial scanning results show that the low b value anomalies of the de-aftershock catalogs are more prominent.Before these M≥5.0 earthquakes in the western region of Yunnan,the time curve of b value present diversified characteristics,but the whole region was in a low b value state before 75%(6/8)M≥5.0 earthquakes,and all of the M≥5.0 earthquakes in this region occurred in areas with low b value or transition zone with high and low b value.And we also find that there is a long period state of low b value in different area.Although the starting time is different,the ending time is the same.We believe that the phenomenon might be the precursor of the 2014 Yingjiang M6.1 earthquake.According to the results,a conclusion can be drawn; low b value in the western region of Yunnan is a precursor of M≥5.0 earthquakes in this region,and we can determine the possible source location of M≥5.0 earthquakes in the future according to the low b value area in the spatial scan.However,the b value cannot be used to predict earthquakes occurred in several days alone,and needs to be used in combination with other seismicity parameters.Long period state of low b value in time curve maybe a precursor of big earthquakes.