[1]LI Layue,YIN Haiquan,MA Lingli,et al.A Retrospective Study of Two MS7.0 Earthquakes in Lijiang and Lushan and Discussions on the Characteristics of Meta-instability[J].Journal of Seismological Research,2023,46(04):461-472.[doi:10.20015/j.cnki.ISSN1000-0666.2023.0061
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A Retrospective Study of Two MS7.0 Earthquakes in Lijiang and Lushan and Discussions on the Characteristics of Meta-instability
Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
46
Number of periods:
2023 04
Page number:
461-472
Column:
Public date:
2023-07-15
- Title:
- A Retrospective Study of Two MS7.0 Earthquakes in Lijiang and Lushan and Discussions on the Characteristics of Meta-instability
- Keywords:
- the Lijiang MS7.0 earthquake; the Lushan MS7.0 earthquake; cross-fault observation; earthquake-case review; meta-instable characteristics; Sichuan-Yunnan area
- CLC:
- P315.7
- DOI:
- 10.20015/j.cnki.ISSN1000-0666.2023.0061
- Abstract:
- The cross-fault observation had been conducted in the epicentral areas of the Lijiang MS7.0 earthquake and the Lushan MS7.0 earthquake before the two earthquakes occurred.According to the deformation analysis methods,and using the cross-fault observational data,we do a retrospective study of the two earthquakes.Guided by the meta-instability theory and on the basis of the laboratory results,we summarize the characteristics of the fault motion varying in time and space,and fault motion's possible manifestations in the meta-instable stage,to identify the synergy of fault activities in the study area,and to explore the signs obtained by the cross-fault observation which indicates that the potential earthquake has entered a meta-instable state.The results show that before the Lijiang and Lushan MS7.0 strong earthquakes,the epicentral areas were mainly in a weak-deformation state with a small rate of activity.This may suggest that the seismogenic fault was locked in the late seismogenic stage,and the accumulation of the stress and strain of the fault in the near field was reaching limit.Three years before the earthquake,significant anomalies of the fault deformation occurred in the 300 km range of the epicentral area,and the anomalies lasted till several months before the earthquake.The fault activity performed a significant synergy.On some cross-fault sites,images similar to the laboratory rock rupture and instability process have been observed.On some sites only the steady state(linear stage)and meta-stable state(deviation from the linear stage)were observed.The meta-instable characteristics on these sites were not clear.We believe that this may be related with the tectonic position of the cross-fault sites and observational periods.
- References:
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Last Update:
2023-10-01