In-Situ Time-Series Experiments Defining Thermal and Chemical Variability in Tidally Perturbed Hydrothermal Systems

我们的计划将探索在梯度驱动的海底环境中发挥作用的相互作用的物理化学过程，重点关注胡安德富卡海脊奋进段热液系统中的三个关键问题。这些问题包括：1)黑烟中相分离的物理和化学后果是什么；2)与高温场有关但也发生在远场的低温扩散喷发流体的来源是什么；3)如何利用潮汐扰动来探索单一热液场内的地下化学和微生物过程。对这些问题的研究对于相分离(例如沸腾)、扩散喷发和潮汐强迫在许多(如果不是全部)山脊水热环境中运行是重要的；所有这些过程都可以在奋进号上的四个热液领域进行直接研究。使用一系列现场物理和化学传感器和一种新的持续流体采样策略，我们将记录潮汐扰动对流体温度、压力、成分和高低温流动区域流量的影响。我们的目标是开发一系列跨学科模型，将产生这些变化的过程联系起来。此外，观测到的潮汐效应将使我们深入了解整个系统对可识别的扰动的反应，并可能使我们能够建立海底流动模式和渗透率结构的模型。

Our program will explore the interactive physical-chemical processes at play in gradient driven submarine environments by focusing on three key questions within a hydrothermal system on the Endeavour Segment of the Juan de Fuca Ridge. These questions include: 1) What are the physical and chemical consequences of phase separation in black smokers; 2) What is the origin of low-temperature diffusely venting fluids that are associated with high-temperature fields, but which also occur far-field, and 3) How can tidal perturbations be used to explore subsurface chemical and microbiological processes within a single hydrothermal field. Investigation of these questions is important in that phase separation (e.g. boiling), diffuse venting, and tidal forcing operate in many, if not all, ridge crest hydrothermal environments; all of these processes are accessible for direct study in the four hydrothermal fields on the Endeavour. Using a range of in situ physical and chemical sensors and a new strategy for sustained fluid sampling, we will document the effects of tidal perturbations in fluid temperature, pressure, composition, and flow rate in areas of both high- and low-temperature flow. Our goal is to develop a series of interdisciplinary models linking the processes that produce these changes. In addition, observed tidal effects will provide insights into the responses of the entire system to identifiable perturbations and may allow us to develop models of subseafloor flow patterns and permeability structure.