SGER: Changes in vent fluid chloride and volatile content as a result of the 2006 eruption at 9N, EPR

智力优势：该提案要求提供资金，以支付参加两次航行的费用，以建立一套基线数据，了解与东太平洋海隆脊2000年综合研究地点9号最近火山爆发有关的化学变化。第一次巡航于2006年6月进行，得出的初步不稳定数据表明，自2004年11月最近一次实地考察以来，气体浓度发生了重大变化。此外，在2006年6月的巡航中，在375 C的通风口放置了一个电阻率仪器，能够以30秒的间隔测量氯化物浓度。通过监测喷口流体氯度的变化，限制了水-岩反应系统内发生的相分离的程度和性质的时间变化。这为热液蚀变提供了重要的控制，因为氯化物在确定矿物溶解度方面具有重要作用。这台仪器将于2006年11月收回，另外两台仪器将部署一年。2006年11月还将收集大约50个流体样本，提取气体成分并送回实验室进行浓缩和同位素分析。在喷发后尽快收集的这些数据将有助于了解热液系统对岩浆扰动的整体行为。更广泛的影响：这项研究是多学科机构间合作的一部分。该项目将直接解决NSF Ridge 2000计划中的关键问题，这些问题涉及岩浆活动与海洋化学的关系以及支持化学合成初级生产者的极端生物圈的地球化学环境。

Intellectual Merit: This proposal requests funding to cover the costs incurred in participating in two cruises to establish a baseline data set for understanding the changing chemistry associated with the recent volcanic eruption at the 9 N East Pacific Rise Ridge 2000 Integrated Studies Site hydrothermal system. The initial cruise took place in June 2006 and resulted in initial volatile data that indicated significant changes in gas concentrations since the latest prior visit to the site in November, 2004. In addition, a resistivity instrument capable of measuring chloride concentrations on a 30 sec interval was placed in a 375 C vent during the June 2006 cruise. By monitoring changes in chlorinity of vent fluids, constraints are placed on time-changes in the degree and nature of phase separation that occurs within the water-rock reaction system. This provides important controls on hydrothermal alteration, since chloride has an important role in determining mieral solubility. This instrument will be recovered in November 2006 and two additional instruments will be deployed for one year duration. On the order of fifty fluid samples will also be collected in November 2006, the gas contents extracted and returned to the laboratory for concentration and isotopic analyses. These data collected as soon as possible after the eruption will be of great use in helping to understand the overall behavior of the hydrothermal system to a magmatic perturbation. Broader Impacts: This research is part of a multi-disciplinary inter-institutional collaboration. This project will directly address key questions from the NSF Ridge 2000 program concerning the relationship of magmatism to ocean chemistry and to the geochemical environment that supports an extremophilic biosphere of chemosynthetic primary producers.