CSEDI: A Test of Dehydration Weakening Hypothesis for the Occurence of Intermediate/Deep-Focus Earthquakes

摘要PIs建议用地震资料约束稳定含水硅酸盐相的实验室实验研究，以检验俯冲板块的脱水弱化是否会引起中、深震源地震。该项目旨在通过实验室高压和高温模拟实验，了解含水相在中深震源地震中的作用。他们将通过实验确定在下降的平板内预期的P-T条件下的水相的存在，简单的MgO-SiO2-H2O和复杂的含水橄榄岩系统中含水相的最大脱水压力，以及含水橄榄岩的脱水/熔化温度作为压力（深度）的函数。他们还建议通过比较洋岩石圈地震活动性的特征，来评价中、深震源事件发生在洋岩石圈俯冲前最初形成的断层上的假设。* * *

96-28861 Fei Abstract The PIs propose to constrain experimental laboratory studies of stable hydrous silicate phases with seismological data to test whether dehydration weakening in subducting slabs causes moderate- and deep-focus earthquakes. The program is aimed at understanding the role of hydrous phases in intermediate and deep-focus earthquakes through high pressure and temperature simulation experiments in the laboratory. They will experimentally determine the existence of hydrous phases for P-T conditions expected within the descending slab, the maximum dehydration pressures of hydrous phases in both simple MgO-SiO2-H2O and complex hydrous peridotite systems, and the dehydration/melting temperatures of hydrous peridotite as a function of pressure (depth). The PIs also propose to compare the characteristics of oceanic lithosphere seismicity to evaluate the hypothesis that intermediate- and deep-focus events occur on faults that were initally formed in oceanic lithosphere before subduction. ***