Collaborative Research: Mapping Melt and Matrix Flow in the Uppermost Mantle: Undershooting the East Pacific Rise between Siquieros and Clipperton

这一“下冲”实验，在东太平洋隆起 在北纬8到10度之间，将使用地震速度 Pn波和Sn波的衰减和异常 如果它们被观测到， 地壳底部附近熔体的垂直分布 沿着脊轴。 的大小和方向 Pn速度的各向异性将用于约束 莫霍面附近的地幔流动方向。 的目标 项目是：（1）绘制地震沿轴变化图 上地幔速度和衰减结构 沿着整个段，（2）映射方向， 上地幔各向异性的大小，（3） 决定了最底层地壳的垂直结构 莫霍面过渡带，以及正下方的上地幔 三个对比点的增生轴，（4） 测量地壳厚度变化沿着整个 变换有界脊段，以及（5）比较结果 与现有的观察和分割模型。

This "undershooting" experiment, on the East Pacific Rise between 8 and 10 degrees north, will use seismic velocity and attenuation and anomalies of Pn arrivals, and Sn waves if they are observed, to map km-scale variations in the vertical distribution on melt near the base of the crust along the ridge axis. The magnitude and orientation of anisotropy in Pn velocities will be used to constrain the direction of mantle flow near the Moho. The goals of the project are to: (1) map along-axis variations in the seismic velocity and attenuation structure of the uppermost mantle along he entire segment, (2) map the orientation and magnitude of anisotropy in the uppermost mantle, (3) determine the vertical structure of the lowermost crust, Moho transition zone, and uppermost mantle directly beneath the axis of accretion at three contrasting sites, (4) measure crustal thickness variations along an entire transform-bounded ridge segment, and (5) compare the results with existing observations and models of segmentation.