Hydrothermal Discharge along the Axis of the East Pacific Rise from 9 Degrees-10 Degrees N

扩张中心的热液环流受控于年轻洋壳的热状况和渗透性结构，因而与沿扩张中心的火山构造作用密不可分。对于几乎所有的扩张中心，热液、岩浆和构造作用之间的相互关系知之甚少，因为对海底的精细测绘仅限于非常小的山脊段。目前建议的奖励将纠正东太平洋隆起的一个主要部分的这种情况。使用Argo深海搜索工具，该项目将从这个扩张中心100英里长的部分获得侧扫声纳和海底摄影。已经利用地表地质和地球物理技术对该区域进行了深入研究，因此整个地壳结构是众所周知的。本项目的目标是：1)绘制热液喷口的位置图，2)将喷口分布与断裂作用和现代火山活动联系起来，3)确定山脊不连续对火山和热液活动的影响。在调查期间获得的数据也将是确定深海钻探地点的关键，以便对洋壳进行采样。

Hydrothermal circulation at spreading centers is governed by the thermal regime and permeability structure of young ocean crust; thus, it is inextricably coupled to the volcano-tectonic processes along spreading centers. For virtually all spreading centers the interrelationships between hydrothermal, magmatic, and tectonic processes are poorly known because fine-scale mapping of the sea-floor has been restricted to very small segments of ridge crest. The present recommended award will rectify this situation for a major segment of the East Pacific Rise. Using the ARGO deep ocean search vehicle, the project will acquire both side-scan sonar and bottom photography from a one hundred mile long segment of this spreading center. This region has already been intensively studied using surface geological and geophysical techniques and the overall crustal structure is therefore well known. Objectives of the present project are: 1) to map the location of hydrothermal vents, 2) relate vent distribution to faulting and recent volcanic activity, and 3) determine the effect of ridge discontinuities on volcanic and hydrothermal activity. Data acquired during the survey will also be critical in locating sites for deep sea drilling to sample ocean crust.