Abstract We examined the spatial distribution of intermediate-depth earthquakes in southern Alaska and the adjacent Aleutian Islands in relation to the deep fluid regime and volcanism. The distribution of earthquake hypocenters is studied in two variables, the depth of focus and the distance from the top of the slab. This approach shows that seismic activity is concentrated at 10–15 and 20–25 km from the top of the downgoing plate. Clusters of seismicity such as these cannot be due to slippage along the boundary between the continental block and the slab. In addition, extended structures of sharply increased seismic activity were found. Their location fits certain quasi-linear relations between pressure and temperature, and can mark metamorphic fronts in the subducted plate. Besides, the spatial earthquake distribution has a peak that appears to be related to active recent volcanism. It can be caused by active dehydration reactions in the subduction plate. These empirical findings testify in favor of the fluid-metamorphic model of earthquakes origin.

中文翻译：

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阿拉斯加俯冲带地震活动与变质作用和深部流体制度的关系

摘要 我们研究了阿拉斯加南部和邻近的阿留申群岛中深度地震的空间分布与深部流体制度和火山活动的关系。以两个变量研究地震震源的分布，即震源深度和距板顶的距离。这种方法表明地震活动集中在距下降板块顶部 10-15 和 20-25 公里处。诸如此类的地震活动群不可能是由于沿大陆地块和板块之间的边界滑动造成的。此外，还发现了地震活动急剧增加的扩展结构。它们的位置符合压力和温度之间的某些准线性关系，并且可以标记俯冲板块中的变质锋。除了，空间地震分布有一个峰值，似乎与近期活跃的火山活动有关。它可能是由俯冲板块中的活跃脱水反应引起的。这些经验发现证明了地震起源的流体变质模型。