SGER: Geologic Constraints on Life in an Antarctic Sub-ice-shelf Environment

这项探索性研究小额赠款支持对2002年灾难性崩塌的拉森- b冰架下新发现的生态系统进行地质和生物学研究。通过结合对海水、沉积物和孔隙水的地球化学测量，以及随后对生物群的分子分析，该项目将描述该群落的特征，并限制冰川过程在启动和维持该群落中的作用。该系统是在极地水域首次发现的此类系统。已知至少含有双壳类动物和细菌垫，它提出了关于亚冰架环境中生命的性质和范围的问题，特别是碳的来源。附近海湾的海洋泥浆有机碳含量很低，上面的冰架将生态系统与开放的海洋植物生产隔离了10,000多年。一种假设是，有机碳是由该地点下面含石油的冰川沉积物提供的，但总的来说，这项工作对理解极端环境下的生命有重要意义，比如雪球地球时期的生命，或者像火星和泰坦这样的冰冷星球上的生命。此外，这可能会对限制全球甲烷预算产生影响。这项工作的更广泛的影响包括支持本科生的研究和提高社会对生命对全球气候变化的响应的理解。

This Small Grant for Exploratory Research supports geologic and biologic research on a newly discovered ecosystem underlying the Larsen-B ice shelf, which collapsed catastrophically in 2002. Through a combination of geochemical measurements of the seawater, sediments, and pore waters, and subsequent molecular analyses of the biota, this project will characterize the community and constrain the role of glacial processes in initiating and sustaining it. The system is the first of its type discovered in polar waters. Known to contain at least bivalves and bacterial mats, it raises questions about the nature and extent of life in sub-ice-shelf environments, especially the source of carbon. The marine mud from nearby embayments has very low organic carbon contents, and the overlying ice shelf secluded the ecosystem from open ocean phytoproduction for over 10,000 years. One hypothesis is that organic carbon is supplied by petroliferous glacial till underlying the site, but overall the work has important implications for understanding life in extreme environments such as those that existed during the Snowball Earth period or on icy worlds such as Mars and Titan. In addition, there may be implications for constraining the global methane budget.The broader impacts of this work include support of undergraduate student research and improving societys understanding of the response of life to global climate change.