Collaborative Research: The Basalt-Hosted Biosphere at North Pond: A Subseafloor Mid-Atlantic Ridge-Flank Microbial

北池是2011年基于IODP 677-Full钻井的目标，是大西洋中脊西侧的一个浅层沉积物塘。先前对北池的钻探和研究表明，年轻的海洋地壳（7-8米）具有活跃的低温流体，通过基底强烈平流。北塘的热力和水文状态是全球大部分脊翼系统的特征，其中岩石圈热量的很大一部分通过热液过程损失，相关的流体-岩石反应显著地改变了海洋和地壳的组成。在许多（其他）地点获得的玄武岩玻璃蚀变皮的某些结构特征的岩石学观察表明，微生物可能在脊侧环境中海洋地壳的蚀变中起重要作用。然而，这一假设尚未得到证实，事实上，我们缺乏可靠的分子、生物化学或生理学数据，这些数据可能会告诉我们对岩石圈中微生物的本质的理解。北塘项目的主要动机是通过系统的实证和实验研究来解决这些问题。激发北池钻探和观测计划的基本科学问题包括：1)在年轻的山脊侧翼中隐藏的微生物群落的性质是什么？它们在海洋地壳变化中起什么作用？2)这些群落是否独特，特别是与海底和沉积群落相比？3)深层微生物群落来自哪里（沉积物、岩石、海水？）？虽然其中一些问题可以通过“典型”抽样来解决。沉积物和岩石的IODP恢复和分析，以及与地壳蚀变、微生物定植、流体动力学和瞬态等活动过程相关的核心问题的进展，需要时间序列观察和实验，以及有关整个系统的化学、物理和流体动力学的背景数据。从某种意义上说，这是采用地球系统科学的方法来解决环境生命科学中的问题。为了实现这一方法，IODP将在北池建立三个长期的海底微生物观测站，以确定本地脊侧微生物并描述它们在氧化改变中的作用。该项目的大部分基础设施需求已经得到支持，使各项准备工作得以顺利进行，并将在2011年与国际发展计划一起部署。这包括硬件、井下取样器、仪器和实验材料的设计、制造和采购。该提案要求在IODP探险后不久，ROV潜水启动观测站，并使用各种采样器和实验，并从周围地区收集支持材料（沉积物，水，岩石），以阐明将在钻孔观测站内采样的地下生物群系的来源。我们还寻求ROV在一年后的时间，以监测这些井眼从钻井作业中恢复的速度，并评估未来的作业和方向。北池的实验也将为正在进行的胡安·德·富卡山脊东侧的研究提供一个很好的比较，这是化学，热，和水文不同。更广泛的影响我们建议将三名专业人士（摄像师和科学作家）带上IODP游轮和本文建议的两艘游轮。这些人将与船上的科学家以及与COSSEE-West和Ocean Leadership相关的岸上联络员一起工作。我们的目标是将教师和教室与这些联络员实时联系起来，在钻探相关科学方面建立新的教育计划，并为更广泛的公众宣传创造新的产品。例如，透过各种媒体产品的创作，从博客、小短文、网络媒体，我们会制作一部聚焦海底生活的纪录片。这个项目的另一个重要的更广泛的影响是为整个社区的环境研究建立长期的基础设施。天文台是一个社区资源，在接下来的十年里，许多不同的研究人员将参与北池的科学研究。事实上，科学家们已经认识到这个地点作为一个关键参考系统的重要性，并从20世纪70年代中期开始对它进行科学研究。该项目标志着北塘社区观测科学新时代的开始，通过建立一个三维仪器阵列的现代钻孔观测站。

Intellectual Merit North Pond, the target for drilling based on IODP 677-Full in 2011, is a shallow sediment pondon the western flank of the mid Atlantic ridge. Prior drilling and study of North Pond revealed youngocean crust (7-8 m.y.) with active, low temperature fluids vigorously advecting through basement. Thethermal and hydrologic state of North Pond are characteristic of large portions of the global ridge flank system, where a significant fraction of lithospheric heat is lost via hydrothermal processes, and theassociated fluid-rock reactions significantly alter the composition of ocean and crust. Petrographicobservations of certain textural features in the alteration rind of basaltic glass that have been retrieved at many (other) sites suggest that microbes may play an important role in alteration of ocean crust in ridge flank settings. However, this hypothesis has not been confirmed and indeed, we lack robust molecular, biochemical, or physiological data that might inform our understanding of the very nature of microbes in the lithosphere. The principal motivation for the North Pond project is to address these questions through systematic empirical and experimental study. The fundamental scientific questions that motivate the drilling and observatory program at North Pond include: 1) What is the nature of microbial communities harbored in young ridge flanks and what is their role in ocean crust alteration? 2) Are these communities unique, particularly incomparison with seafloor and sedimentary communities? 3) Where do deep-seated microbial communities come from (sediment, rock, seawater?)? While some of these questions can be addressed through sampling with ?typical? IODP recovery and analysis of sediment and rock, progress at the heart of questions that relate to active processes such as crustal alteration, microbial colonization, fluid dynamics, and transience, require time-series observation and experiments, coupled with contextual data concerning chemical, physical, and hydrodynamics of the system as a whole. In a sense, this is taking an Earth systems science approach to solving problems in the environmental life sciences. To achieve this approach IODP will establish three long-term subseafloor microbial observatories in North Pond in order to identify indigenous ridge flank microbes and delineate the role that they play in oxidative alteration. A major portion of the infrastructural needs for this project have already been supported, enabling preparations, which are now well underway for deployment in 2011 with the IODP. This includes the design, fabrication, and purchasing of hardware, down hole samplers, instruments, and experimental materials. This proposal requests ROV dives shortly after the IODP expedition to initiate the observatory and populate it with a variety of samplers and experiments and to collect supporting material (sediments,water, rocks) from the surround area to elucidate sources for the subsurface biome that will be sampled within borehole observatories. We also seek ROV time one year later to monitor how fast these boreholes recover from drilling operations and gauge future operations and direction. The experiments at North Pond will also provide an excellent comparison for ongoing studies on the eastern flank of the Juan de Fuca Ridge, which is chemically, thermally, and hydrologically distinct. Broader Impacts We propose to bring three professionals (videographers and science writers) on board the IODP cruise and the two cruises proposed herein. These individuals will work with ship-board scientists and shore-based liaisons associated with COSSEE-West and Ocean Leadership. Our objectives are to link teachers and classrooms with these liaisons in real-time, establish new educational programs in drilling related science, and create new products for broader public outreach. For example, through the creation of a variety of media products, from blogs, vignettes, and online media, we will develop a documentary that focuses on life below the bottom of the ocean. Another important broader impact of this project is in the establishment of long-term infrastructure for community wide study of this environment. Observatories are a community resource, and over the next decade many dozens of diverse researchers will participate in scientific study at North Pond. Indeed, scientists have recognized the importance of this site as a key reference system and have engaged in scientific study of it since the mid 1970?s. This project marks the beginning of a new era of observing science for the community at North Pond, through the establishment of a 3-D array of instrumented modern borehole observatories.