Tonga and Fiji Seismic Arrays for Investigating Slab Processes and Upper Mantle Phase Transformations

题目：用于研究板块过程和上地幔相变的汤加和斐济地震阵列作者：Douglas A. Wiens和Gideon Smith，华盛顿大学正在利用来自两个密集地震阵列的地震数据研究汤加俯冲带的详细结构。这些阵列将部署大约一年，一个在活动岛弧内（汤加），另一个在弧后环境中（斐济）。这些阵列的数据被用来描述和模拟地震波在俯冲大洋板块和邻近地幔内的传播效应。这些波的传播效应是与俯冲板块内部和附近的地震速度不连续的相互作用造成的。与远震记录的数据相比，速度不连续的深度、速度对比和清晰度将有助于更好地了解俯冲板块和周围地幔中的温度、矿物学和水的存在，从而获得更多的空间细节。密集的阵列数据也允许对深层地震的力学进行更高精度的研究。

Abstract for proposal EAR0001158 (PH #51x; Spring 2000 Panel)Title: Tonga and Fiji Seismic Arrays for Investigating Slab Processes and Upper Mantle Phase TransformationsPI's: Douglas A. Wiens and Gideon Smith, Washington UniversityThe detailed structure of the Tonga subduction zone is being studied with seismic data from two dense seismic arrays. The arrays are to be deployed for about a year, one within the active island arc (Tonga), the other in the backarc environment (Fiji). Data from the arrays is used to characterize and model seismic wave propagation effects within the subducting oceanic plate and the adjacent mantle. These wave propagation effects result from interactions with seismic velocity discontinuities in and near the subducting plate. The depths, velocity contrasts, and sharpness of the velocity discontinuities will be used to help better understand the temperature, mineralogy and presence of water in the subducting slab and the surrounding mantle at greater spatial detail than is possible from data recorded teleseismically. Dense array data also allows higher precision studies of the mechanics of deep earthquakes.