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研究了不列颠哥伦比亚省西南部地下胡安·德富卡消减板块内高精度的震源与从接收函数分析和反射地震数据所得速度结构之间的关系。用双差算法对深度在40～65 km的108个地震进行了重新定位,得到了精确的地震位置。重新确定的地震活动与构造信息间的互相关显示出地震集中在消减的洋壳的顶部,而更深层位的地震活动性位于地幔顶部胡安·德富卡消减板块内。消减板块的构造与地震活动性之间的强相关性表明,地震破裂是由板块内的力学强度改变引起的,这支持了相变和热岩状态在双重地震层的地震成因中起重要作用的假说。
The relationship between high-precision seismic sources in the subducted Juan de Fuca subduction plate in the southwestern British Columbia and the velocity structure obtained from the receiver function analysis and reflected seismic data was studied. The 108 earthquakes with a depth of 40 ~ 65 km were repositioned by the double difference algorithm, and the exact seismic position was obtained. Correlation between redefined seismic activity and tectonic information shows that the earthquakes are concentrated at the top of the depleted oceanic crust, while the seismicity of deeper layers is located within the Juan de Fuca subduction plate at the top of the mantle. The strong correlation between the structure of the abatement plate and the seismicity suggests that the rupture of the earthquake was caused by a change in the mechanical strength within the plate, supporting the important role of the phase transitions and hot rock states in the seismic genesis of the dual seismic layers hypothesis.