Analysis on Stress State in Xinyi-Lianjiang Fault Area

HUANG Yuanmin; DU Long; SHAO Ye; WANG Zhengya

doi:10.13512/j.hndz.2016.03.003

Abstract：Using the seismic data recorded by the Guangdong and Guangxi regional seismic network from January 1st,1972 to March 31st,2016,the paper obtained the spatial distribution of several seismicity parameters (including a and b values in the frequency-magnitude relationship,and the local recurrence intervals TL) in Xinyi-Lianjiang fault and its surrounding area to discuss the stress state in the fault.The results show that:the spatial distribution of several seismicity parameters was significantly heterogeneous in the fault area.The Beibu Gulf area in the southwest section of the fault had the characteristic of the low b-value,low avalue,and the shortest recurrence intervals TL.All these implied that this section of the fault might have been locked under the high stress and more likely to generate moderate-strong earthquakes.The stress state and the degree of locking in the central section of fault,where it is the intersection of Xinyi-Lianjiang fault and Suixi fault,were lower than Beibu Gulf section.Because it was the intersection of two faults,the stress tiggering on Xinyi-Lianjiang fault from the moderate-strong earthquakes in Suixi fault could not be ignored.There were a lot of small earthquake in Gaozhou reservoir area,and its stress release was mainly based on the small earthquake activity.