Seismological Components of the MELT Experiment on the Southern East Pacific Rise

9402375福赛斯这项实验旨在对大洋中脊下的熔体分布和上升流模式提供直接的观测约束。利用海底仪器阵列研究地幔中的电磁波和地震波传播，将提供可以反演的测量结果，以找出速度和传导性结构的水平和垂直变化，可用于检验流动的理论模型。一组47个海底地震仪将部署在南17度的东太平洋隆起上，为期六个月，以记录远震和地区性震源。利用台阵记录的P波和S波以及其他体波相位和Love面波和Rayleigh面波探测地幔在距脊轴100~200公里和几百公里范围内的横向变化。主要目的是确定在脊轴正下方是否存在高熔体浓度和低地震速度的狭窄区域，并绘制其垂直和水平范围图。另一个目标是限制上升流的模式。*_

9402375 Forsyth This experiment is designed to provide direct observational constraints on the distribution of melt and the pattern of upwelling beneath a mid-ocean ridge. Studies of electromagnetic and seismic wave propagation in the mantle with arrays of ocean- bottom instruments will furnish measurements that can be inverted to find horizontal and vertical variations in velocity and conductivity structure that can be used to test theoretical models of flow. An array of 47 ocean-bottom seismometers will be deployed for six months on the East Pacific Rise at about 17 degrees south to record teleseismic and regional earthquake sources. P and S waves, as well as other bady wave phases and Love and Rayleigh surface waves recorded by the array will be used to probe lateral variations in mantle to a depth of 100 to 200 km and out to several hundred km from the ridge axis. The main goal is to establish whether there is a narrow region of high melt concentration and low seismic velocities directly beneath the ridge a1xis and to map its vertical and horizontal extent. Another goal is to constrain the pattern of upwelling. *** _______________________________ 1