基于全国地下流体观测网的水温观测数据,分析2022年9月5日四川泸定 M_S6.8 地震引起的水温同震响应特征,并结合同震静态应变场探讨了水温同震响应机理。结果表明,泸定 M_S6.8 地震水温同震观测点主要分布在龙门山断裂带和川滇菱形块体中南部; 震中距Δ≤500km范围内水温同震以下降—恢复型和上升型为主,水温同震项数及测项比随震中距的增加逐渐减少; 水温同震响应幅度与震中距和地震能量密度显著相关,且随震中距的增加呈指数衰减,随地震能量密度的增加呈指数增大; 水温同震响应持续时间主要集中在1天以内,持续时间随震中距的增加呈指数衰减。

Based on the water temperature observation data of the national underground fluid observation network,this paper analyzed the characteristics of the water temperature coseismic response caused by the Sichuan Luding M_S6.8 earthquake on September 5,2022,and discussed the mechanism of the water temperature coseismic response related with the coseismic static strain field. The results show that the water temperature coseismic observation points of the Luding M_S6.8 earthquake are mainly distributed in the Longmenshan fault belt and the central south of the rhombus block in Sichuan and Yunnan Provinces. In the range of epicentral distance Δ≤500km,coseismic responses are dominant by patterns of decline-recovery and rise. The number of water temperature coseismic factors and their ratio gradually decrease with the increase of the earthquake epicentral distance. The coseismic response amplitude of water temperature is significantly related to the epicentral distance and seismic energy density,showing exponential decay with the increase of epicentral distance while increasing exponentially with the increase of seismic energy density. The duration of the water temperature coseismic response is mainly within one day and decreases exponentially with the increase of epicentral distance.

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中国地震局地震预测开放基金(XH23069D)、中国地震局震情跟踪定向工作任务(2022010309)共同资助