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

2011年根据IODP 677-Full钻探的目标是Intellectual Merit North Pond，它是大西洋中脊西侧的一个浅沉积物池塘。先前对北池的钻探和研究揭示了北大洋地壳（7-8百万年）活跃的低温流体通过基底剧烈平流。北池的热状态和水文状态是大部分全球海脊侧翼系统的特征，在那里，岩石圈热量的很大一部分通过热液过程损失，相关的流体-岩石反应显著改变了海洋和地壳的组成。岩石学观察的玄武岩玻璃蚀变皮中的某些纹理特征，已在许多（其他）网站检索表明，微生物可能发挥重要作用，洋壳的变化在脊侧翼设置。然而，这一假设尚未得到证实，事实上，我们缺乏强有力的分子，生物化学或生理数据，这些数据可能会让我们了解岩石圈中微生物的本质。北塘项目的主要动机是通过系统的经验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）年轻脊侧翼中微生物群落的性质是什么，它们在洋壳蚀变中的作用是什么？2)这些生物群落是否独特，特别是与海底和沉积生物群落相比？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抽样解决？典型的？沉积物和岩石的IODP恢复和分析，与地壳蚀变，微生物定植，流体动力学和瞬变等活动过程相关的问题的核心进展，需要时间序列观察和实验，以及有关化学，物理和流体动力学的背景数据系统作为一个整体。从某种意义上说，这是采取地球系统科学的方法来解决环境生命科学中的问题。为实现这一方法，海洋发展方案将在北池建立三个长期海底微生物观测站，以确定本土脊侧翼微生物，并说明它们在氧化蚀变中发挥的作用。这一项目的大部分基础设施需求已经得到支持，从而使筹备工作得以进行，目前正在顺利进行，以便在2011年与综合海洋发展方案一起部署。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。该提案要求在国际大洋钻探计划考察后不久进行潜水，以启动观测站，并在观测站安装各种采样器和实验设备，并从周围地区收集辅助材料（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落的来源。我们亦会在一年后安排时间监察该等钻孔从钻探作业中恢复的速度，并评估未来的作业及方向。北池的实验也将为正在进行的胡安·德富卡海岭东侧的研究提供一个很好的比较，这是化学，热，水文不同。我们建议让三名专业人员（摄像师和科学作家）参加海洋学发展方案的巡航和本文提议的两次巡航。这些人将与船上的科学家和与COSSEE-West和海洋领导有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，建立钻井相关科学的新教育计划，并为更广泛的公众宣传创造新产品。例如，通过创建各种媒体产品，从博客，小插曲，和在线媒体，我们将开发一个纪录片，重点是生活在海底以下。这个项目的另一个重要的更广泛的影响是建立长期的基础设施，为社区范围内的研究这一环境。观测站是一个社区资源，在未来十年内，数十名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网站作为一个关键的参考系统的重要性，并从事科学研究，它自1970年中期？S.该项目标志着北池社区观测科学新时代的开始，通过建立一个3-D阵列的仪器化现代钻孔观测站。

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.