The Shallow Structure of the East Pacific Rise near Latitude9 Degrees 30' North

在海底扩张中心产生的浅海地壳的性质很少受到现有地球物理资料的约束。最近的研究表明，地壳最浅层的特征是极低的地震速度，但速度随着深度的增加而迅速增加。了解控制这些变化的过程对于确定地壳的孔隙度、地壳岩石的蚀变以及地壳钻探数据的局部和区域意义非常重要。目前的拨款将支持对东太平洋东隆起的一段近底部折射研究。该项目将利用部署在海底的接收器和声源，对浅层地壳进行详细研究。这种技术将提供比普通水面舰艇观测更高分辨率的研究。实验数据将与沿着同一段山脊计划的钻探结果进行比较。该项目的主要研究人员在地壳数据的实验和理论分析方面都有杰出的记录。

The nature of the shallow oceanic crust produced at seafloor spreading centers is poorly constrained by available geophysical data. Recent studies suggest that the shallowest layers of the crust are characterized by extremely low seismic velocities, but that the velocity increases rapidly with depth. Understanding the processes that control these variations are important in determining the porosity of the crust, alteration of crustal rock, and the local and regional significance of crustal drilling data. The present award will support a near bottom refraction study of a segment of the East Pacific Rise in the eastern equatorial Pacific. The project will allow a detailed study of the shallow crust by using both a receiver and acoustic source deployed at the seafloor. This technique will provide a higher resolution study than is available from normal surface ship observations. Data from the experiment will be compared to drilling results which are planned along this same section of ridge. The principal investigators on this project have distinguished records in both experimental and theoretical analysis of crustal data.