EGU22-648, updated on 26 Mar 2022
https://doi.org/10.5194/egusphere-egu22-648
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

In situ stress state and earthquake hazard assessment in Dayi seismic gap of the Longmenshan thrust belt

bing li1,2, Jinshui Huang2, and Furen Xie1
bing li et al.
  • 1National Institute for Natural Hazards, Ministry of Emergency Management of China, Beijing, China (mycoon@139.com)
  • 2School of Earth and Space Sciences, University of Science and Technology of China,

The Dayi seismic gap of the Longmenshan thrust belt is located between the ruptures of the 2008 Wenchuan Earthquake and the 2013 Lushan Earthquake, with a length of about 40 ~ 60 km. So far, it has been still a heated debate on whether the Dayi seismic gap has the hazard of strong earthquakes in the near future. The occurrence of a strong earthquake in the seismic gap is closely related to the existence of high stress accumulation and the most direct method is to measure the borehole stress in the field. In order to find out the present stress state, in-situ stress measurements were carried out at the hanging wall and footwall of Dachuan-Shuangshi fault zone in Dachuan Town. The results showed that the hanging wall and footwall of Dachuan-Shuangshi fault zone in Dayi seismic gap are in a high-stress state. Based on seismicity parameter b-value, crustal velocity structure, GPS deformation monitoring data and temperature data, etc., it can be learned that there is a positive correlation coupling relationship between near surface shallow stress and deep stress. In this paper, a response model of shallow stress to deep locking was established. It was speculated that Dayi seismic gap has the potential hazard of strong earthquakes. This research result not only deepens the understanding of the relationship between stress and earthquake preparation, but also provides an effective scientific method for identifying seismic hazards in other active fault seismic gaps.

How to cite: li, B., Huang, J., and Xie, F.: In situ stress state and earthquake hazard assessment in Dayi seismic gap of the Longmenshan thrust belt, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-648, https://doi.org/10.5194/egusphere-egu22-648, 2022.