Collaborative Research: Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)提供资金的。RAGES项目(用于探索和科学的接地区机器人接入)是WISSARD(Whillans冰流冰下接入研究钻探)综合倡议的三个研究组成部分之一，该倡议由美国国家科学基金会极地方案办公室南极分部南极综合系统科学计划资助。WISSARD的总体科学目标是评估西南极冰流下的水在相互关联的冰川学、地质学、微生物学、地球化学和海洋系统中的作用。WISSARD的RAGES部分集中于冰流接地带(GZ)的稳定性，GZ是冰、海水、冰川和海底沉积物相互作用的区域。根据我们目前有限的数据和模拟工作，GZ可能受到(I)内部冰流动力学、(Ii)冰下湖泊的充填/排出循环、(Iii)海水变暖导致的融化增加和/或(Iv)冰下沉积物(TIL)供应到GZ的速率的干扰。由于在未来全球变暖的情况下，GZ对冰盖稳定的贡献未知，因此被视为高度优先的调查目标。RAGE的三个主要科学目标是评估：(A)相对于上述四个主要变量大小的南极西部冰盖(WAIS)的稳定性；(B)接地带沉积系统保存过去WAIS动态的重要记录的程度；(C)微生物活动和冰下地球化学风化在向WAIS接地带、罗斯冰架(RIS)空腔和生产力高的南大洋提供养分方面的重要性，这可能最终影响全球生物地球化学循环。RAGES实地采样计划将地面地球物理调查与钻孔和冰下采样和测量相结合。这些钻孔提供：(1)用于生物、地球化学、冰川学、沉积学和微古生物学分析的冰下水、沉积物和基冰的样本；(2)冰下和冰架下洞穴的物理和化学条件及其空间变异性的测量；(3)关于基准线和附近冰架下洞穴内的沉积物类型、状态和变化的数据。将部署的独特工具包括多传感器次冰车(遥控运载火箭)和长期冰下海洋系泊。信息优点：政府间气候变化专门委员会的最新报告认识到，评估未来全球海平面变化的最大不确定性源于对冰盖动力学和冰盖易受海洋和大气变暖影响的了解不足。仅南极西部冰盖的解体就将导致全球海平面上升3-5米，这使其成为科学关注的焦点，因为它可能容易受到内部或海洋驱动的不稳定的影响。整个WISSARD项目将检验最重要的假设，即活跃的水排放连接各种冰下环境，并对冰盖流动、地球化学、新陈代谢和系统发育多样性以及生物地球化学转化发挥主要控制作用。更广泛的影响：社会相关性：全球变暖、冰盖融化以及由此导致的海平面上升具有高度的社会相关性。科学资源开发：在中断9年后，WISSARD将为美国科学界提供访问和研究亚冰盖环境的新能力。开发这一技术基础设施将使更广泛的科学界受益，资产将通过NSF-OPP钻井承包商获得，供未来使用。RAGES项目通过结合使用复杂的新仪器，如亚冰车和冰下海洋/湖泊系泊系统，代表了极地技术的重大进步。此外，这些项目将开创一种方法，落实国家研究理事会关于探索和研究冰下环境的环境管理原则委员会(2007年)的建议。教育和外联(E/O)：这些活动分为四类：i)通过将极地研究完全纳入我们的研究计划来增加学生对极地研究的参与；ii)通过将有前途的年轻研究人员纳入我们的计划来引入新的极地科学研究人员；iii)通过结合各种教师和NSTA计划来促进K-12教学计划；以及iv)通过科普杂志、博物馆活动以及录像和纪录片等场所接触到更多的公众受众。总之，WISSARD将通过向公众传达访问和研究可能是地球上最后一些未被探索的水生环境的兴奋之情，促进对南极洲的科学探索，这些环境可能是欧罗巴和火星上外星生命栖息地的潜在类比。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The RAGES project (Robotic Access to Grounding zones for Exploration and Science) is one of three research components of the WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) integrative initiative that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The RAGES component of WISSARD concentrates on the stability of ice stream grounding zones (GZ), the area where the ice, ocean waters and glacial and sea floor sediment interact. Based on our present limited data and modeling efforts, GZs can be perturbed by (i) internal ice stream dynamics, (ii) filling/draining cycles of subglacial lakes, (iii) increased melting by warming ocean waters, and/or (iv) rates of subglacial sediment (till) supply to the GZ. GZs are seen as high priority targets to investigate due to their unknown contributions to ice sheet stability under future global warming scenarios. The three main science goals for RAGES are to assess: (a) West Antarctic Ice Sheet (WAIS) stability relative to the magnitudes of the four main variables listed above; (b) the degree to which grounding-zone sedimentary systems house important records of past WAIS dynamics; and (c) the importance of microbial activity and subglacial geochemical weathering in supplying nutrients to the WAIS grounding zone, the Ross Ice Shelf (RIS) cavity, and the highly productive Southern Ocean that may ultimately influence global biogeochemical cycles. The RAGES field sampling plan integrates surface geophysical surveys with borehole and subglacial sampling and measurements. The boreholes provide: (1) samples of subglacial water, sediments, and basal ice for biological, geochemical, glaciological, sedimentological, and micropaleontological analyses; (2) measures of subglacial and sub-ice-shelf cavity physical and chemical conditions and their spatial variability; and (3) data on sediment types, state and change of the subglacial water discharge, oceanography, and basal ice at the grounding line and within the nearby sub-ice-shelf cavity. Unique tools to be deployed include a multisensor Sub-Ice ROVer (Remotely Operated Vehicle) and long-term, sub-ice oceanographic moorings.INTELLECTUAL MERIT: The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. BROADER IMPACTS: Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. The RAGES project represents a significant advance in polar technology by incorporating the use of complex new instrumentation like the Sub-Ice ROVer and subglacial ocean/lake mooring systems. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars.