2018年佳木斯汤原ML 4.4地震震源机制及地震趋势分析

2018年1月15日佳木斯汤原县发生M_L 4.4地震，采用ISOLA方法反演矩张量解，结果显示为逆冲型地震，兼少量走滑成分。结合震源区地质构造背景，推断依舒断裂北段通河-汤原段西支断裂为发震构造，主压应力轴与背景应力场方向不一致。分析认为，黑龙江亚板块由东南转向东北运动，造成断层两侧应力产生差异，区域应力场调整诱发汤原M_L 4.4地震。

Analysis of earthquake mechanism and seismic trend of Jiamusi Tangyuan ML 4.4 earthquake in 2018

The M_L 4.4 earthquake occurred in Jiamusi Tangyuan county on January 15, 2018. An ISOLA method is used to invert the moment tensor solution. The inversion result shows that this earthquake is a reverse-impact type f earthquake with a small amount of sliding components. Combining the geological structure background of seismic source area, it is concluded that the fault of the western branch of Tonghe-Tangyuan in the northern section of Yishu faulit is the seismogenic structure of this earthquake. The direction of the main pressure axis is inconsistent with the direction of the background main stress field.
The research result reveals that the M_L 4.4 earthquake is induced by the stress difference between the two sides of the fault caused by the shifting of the subplate block of Heilongjiang from southeast to northeast. And it is the result of the adjustment of the regional stress field.