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

合作研究：北池塘玄武岩生物圈，大西洋中脊侧海底微生物观测站

• 批准号: 1060634
• 负责人: Katrina Edwards
• 金额: $ 6.66万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-15 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1060634&HistoricalAwards=false
• 关键词: Collaborative; Research; Basalt; Hosted; Biosphere

Intellectual MeritNorth 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 ImpactsWe 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.

Knowledge MeritNorth Pond是2011年根据IODP 677-Full进行钻探的目标，是位于大西洋中部海脊西侧的一个浅沉积池塘。之前对北池的钻探和研究发现了年轻的地壳(7-8英里)。有活跃的低温流体在地下室里旺盛地平流。北池的热和水文状态是全球海脊侧面系统的一大部分的特征，在那里，岩石圈的很大一部分热量通过热液作用而损失，相关的流体-岩石反应显著改变了海洋和地壳的组成。在许多(其他)地点发现的玄武岩玻璃蚀变皮中的某些结构特征的岩相学观察表明，微生物可能在海脊两侧洋壳的蚀变中发挥重要作用。然而，这一假设还没有得到证实，事实上，我们缺乏强有力的分子、生化或生理数据来帮助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实证和实验研究来解决这些问题。推动北池钻探和观测计划的基本科学问题包括：1)年轻的海脊两侧蕴藏的微生物群落的性质是什么，它们在洋壳变化中扮演的角色是什么？2)这些群落是独一无二的，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？)？虽然这些问题中的一些可以通过抽样来解决，但典型的？沉积物和岩石的IODP回收和分析是与地壳变化、微生物定居、流体动力学和瞬变等活动过程有关的问题的核心进展，需要进行时间序列观察和实验，并结合关于整个系统的化学、物理和流体动力学的背景数据。从某种意义上说，这是在用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，IODP将在北池建立三个长期海底下微生物观测站，以确定土著脊侧微生物，并描绘它们在氧化蚀变中所起的作用。该项目的基础设施需求的很大一部分已经得到支持，使筹备工作得以顺利进行，以便在2011年与IODP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。这项提议要求水下机器人在IODP探险后不久潜水，启动观测站，在观测台上安装各种取样器和实验，并从周围地区收集支持材料(沉积物、水、岩石)，以查明将在钻孔观测站内取样的地下生物群的来源。我们还寻求一年后的ROV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极好的对比，那里在化学、热和水文方面都是不同的。布罗德影响我们建议在IODP邮轮和这里建议的两次邮轮上配备三名专业人员(摄像和科学作家)。这些人将与船上的科学家以及与COSSEE-West和Ocean领导层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系实时联系起来，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产品。例如，通过创作各种媒体产品，从博客、小插曲和网络媒体，我们将开发一部关注海底生活的纪录片。这个项目的另一个重要的更广泛的影响是建立了长期的基础设施，以便在整个社区范围内研究这种环境。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在北池参与科学研究。事实上，科学家们已经认识到这个地点作为一个关键参照系的重要性，并从1970年中期开始对其进行科学研究？S。这个项目标志着通过建立一个3-D现代仪器钻孔观测台阵列，为北塘社区观测科学的新时代的开始。