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最近日本列岛地震台网的加强揭示了日本西南部呈带状分布的低频持续颤动事件的发生。在那里,菲律宾海消减板块达到30～40km的深度。选择具有相对清晰的P波初动的颤动段估计出颤动源的深度。颤动源区被认为对应于地壳最底部,位于地壳、地幔楔和消减板块之间的三角形边界地区。较长的颤动持续时间表明了与产生颤动相关的流体的存在。根据高温高压实验数据,最有可能的流体被认为是消减板块中的绿泥石和闪石在脱水过程中产生的水。带状分布的北部可能以地幔楔的边缘为边界,因为蛇绿岩建造吸收了流体水。
The recent strengthening of the Seismic Network of the Japanese Archipelago reveals the occurrence of low-frequency continuous chatter events in the zonal distribution in southwestern Japan. There, the Philippine Sea subduction plate reached a depth of 30 ~ 40km. Choosing the jitter section with relatively clear P-wave initial motion estimates the depth of the jitter source. The wobbling source zone is considered to correspond to the bottom of the earth’s crust, located in the triangular boundary area between the crust, the mantle wedge and the abatement plate. Longer duration of fibrillation indicates the presence of fluid associated with fibrillation. According to the experimental data of high temperature and high pressure, the most likely fluid is considered to be the water produced during dewatering by the chlorites and amphiboles in the slab. The north of the belt may be bounded by the edge of the mantle wedge because ophiolite construction absorbs fluid water.