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

扩张中心的热液循环受年轻洋壳热状态和渗透结构的支配；因此，它与扩张中心沿线的火山构造作用有着不可分割的联系。对于几乎所有的扩张中心，人们对热液、岩浆和构造过程之间的相互关系知之甚少，因为对海底的精细测绘一直局限于非常小的脊顶部分。目前推荐的奖项将为东太平洋崛起的一个主要部分纠正这种情况。该项目将使用ARGO深海搜索船，从这个扩散中心100英里长的部分获取侧扫声纳和海底照片。人们已经利用地表地质和地球物理技术对这一地区进行了深入的研究，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；2)将热液喷口分布与断裂和最近的火山活动联系起来；3)确定山脊不连续对火山和热液活动的影响。在调查过程中获得的数据也将是确定深海钻探地点以取样海洋地壳的关键。

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.