COLLABORATIVE RESEARCH: RESISTIVITY MAPPING OF SUBSURFACE MICROBIAL HABITATS IN THE MCMURDO REGION

知识优势：pi建议研究在南极环境中使用机载时域电磁（TEM）绘制地下电阻率图的可行性。该方法通过区分高电阻率（冰川冰和基岩、永久冻土）和低电阻率材料（被盐水饱和的地质材料）至300米或更深的深度，提供了一种非侵入性的方法来确定冰下和亚永久冻土环境中的盐度分布。TEM系统将安装在直升机上，在难以到达的地形上生成内部电阻率结构的三维地图。TEM系统的部署将是一个概念验证，以确定它是否可以用于绘制南极冰下和亚永久冻土环境中的水的电导率和深度。这些数据将有助于研究人员更好地了解冰下微生物生态系统的全球功能以及冰下栖息地的性质和范围。将地球物理测量与生物地球化学测量相结合，将提供一个独特的机会，将水文和微生物过程在地下环境中的作用联系起来。这项工作的科学目标是：1)建立盐水来源和冰下水运动的空间范围的流动模型；2)测量冰下盐水的碳通量和生物量；3)确定冰下盐水如何以及为什么只在血瀑布释放。更广泛的影响：该项目将包括学生培训、南极保护（Blood Falls正被提议作为一个新的南极特别保护区），以及由外联协调员制定的正式外联。正式的推广计划将是一本关于南极研究的插图书。为了确保其更广泛的影响目标的成功，所有pi将与达特茅斯学院和WISSARD项目教育和外展协调员密切合作。

Intellectual Merit: The PIs propose to investigate the feasibility of using airborne Time Domain Electromagnetic (TEM) to map subsurface resistivity in the Antarctic environment. This method offers a non-invasive way to determine the distribution of salinity in subglacial and sub-permafrost environments by distinguishing between high resistivity (glacier ice and bedrock, permafrost) and low resistivity materials (geologic materials saturated by salty water) to a depth of 300 m or greater. The TEM system will be helicopter mounted to generate three-dimensional maps of internal resistivity structure over inaccessible terrain. Deployment the TEM system will be a proof-of-concept to determine whether it can be used to map conductivity and depth of waters in Antarctic subglacial and sub-permafrost environments. These data will help researchers better understand the global function of subglacial microbial ecosystems the nature and extent of subglacial habitats. Coupling geophysical surveying with biogeochemical measurements will provide a unique opportunity to link the role of hydrology and microbial processes in the subsurface environments. The scientific goals of this work are to: 1) Develop flow models of the spatial extent of the brine source and subglacial water movement 2) Measure carbon flux and biomass from the subglacial brine 3) Determine how and why subglacial brine is released exclusively at Blood Falls.Broader impacts: This project will include student training, Antarctic conservation (Blood Falls is being proposed as a new Antarctic Specially Protected Area), and formal outreach developed with an outreach coordinator. The formal outreach plan will be an illustrated book on Antarctic research. To ensure the success of their broader impact goals, all PIs will work closely with Dartmouth College and the WISSARD Project Education and Outreach Coordinator.