[1]LI Xia,ZHAO Yuhong,FENG Lili,et al.The Variation of Geo-electric Field at the Dulan Seismic Station before the 2021 Maduo,Qinghai MS7.4 Earthquake[J].Journal of Seismological Research,2021,44(04):642-649.
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The Variation of Geo-electric Field at the Dulan Seismic Station before the 2021 Maduo,Qinghai MS7.4 Earthquake
Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
44
Number of periods:
2021 04
Page number:
642-649
Column:
Public date:
2021-11-10
- Title:
- The Variation of Geo-electric Field at the Dulan Seismic Station before the 2021 Maduo,Qinghai MS7.4 Earthquake
- Keywords:
- the Dulan geo-electric field; the Maduo MS7.4 earthquake; premonitorily abnormal characteristics; case-study of earthquakes
- CLC:
- P319.1
- DOI:
- -
- Abstract:
- On May 22,2021,an MS7.4 earthquake occurred in Maduo County,Qinghai Province.Before the earthquake,the observed data of geo-electric field by the Dulan stotion shawed significant abnormal changes and were of credibility to some extent.And the form of the curve of the data is similar to that of the data before the 2019 Xiahe MS5.7 earthquake.The main manifestations of the anomaly are as follows:Firstly,the original observed data showed anomalous annual variations in different degrees in July 2020,and the 6 survey channels of long distance and short polar distance changed synchronously.The annual variations mainly decreased and rose rapidly after reaching the lowest point.Secondly,the ratio of the observed data between the long polar distance and short polar distance of the geo-electric field showed that the V-shaped variations appeared sharply and rapidly in all directions prior to the earthquake.Thirdly,after the annual variation is removed by the Correlation Moment Plane method,the curves of the daily observed mean value of the geo-electric field showed a trend or a rapid decline after May 2020,and the interval change values are all less than the historic average level,or even lower than twice the mean square deviation level,and the abnormal form is significant.We believe that the abnormal variations of the geo-electric field in Dulan region since the year 2020 are related with the genesis and evolution of the Maduo MS7.4 earthquake.
- References:
- -
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Last Update:
2021-11-10