[S-GD02] 地殻変動

[SGD02-P09] Coseismic Effects of the Maduo MS7.4 Earthquake on Crustal Movement in the Northeastern Margin of the Tibetan Plateau

*Zhengyi Yuan¹、Huaizhong Yu¹ (1.China Earthquake Networks Center)

キーワード：coseismic deformation, seismic activity, spherical wavelet method, crustal strain rate

If the tensile and compressive properties of the coseismic and background strain rate field are consistent, coseismic deformation is conductive to the further accumulation of strain energy in this region, thus increasing the potential possibility of earthquake occurrence. Conversely, if the tensile and compressive properties are opposite, coseismic deformation can offset the accumulated seismic moment in the above area, reducing the potential seismic risk. Based on this theory, the GNSS coseismic displacements of the 2021 Maduo MS7.4 earthquake are used to calculate coseismic strain rate in the northeastern margin of the Tibetan Plateau by the spherical wavelet method, meanwhile, combined with the evolution feature of b-value in high-strain areas, the adjustment process of stress field in the same region is discussed. By calculating cumulative seismic moment rates induced by coseismic events and comparing them with differences in actual seismic moment release rates before and after earthquakes, we summarize how coseismic deformation influences changes in potential seismic activity on surrounding faults at different time scales. This provides a basis for post-earthquake risk analysis and location determination of aftershock in the coseismic deformation areas.