Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica

麦克默多干谷的隐秘水文学：水道对南极洲泰勒谷水和地球化学预算的贡献

• 批准号: 1343649
• 负责人: Joseph Levy
• 金额: $ 32.8万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1343649&HistoricalAwards=false
• 关键词: Cryptic; Hydrology; McMurdo; Dry; Valleys

Intellectual Merit: The PIs propose to quantify the hillslope water, solute, and carbon budgets for Taylor Valley in the McMurdo Dry Valleys, using water tracks to investigate near-surface geological processes and challenge the paradigm that shallow groundwater is minimal or non-exixtant. Water tracks are linear zones of high soil moisture that route shallow groundwater downslope in permafrost dominated soils. Four hypotheses will be tested: 1) water tracks are important pathways for water and solute transport; 2) water tracks transport more dissolved silica than streams in Taylor Valley indicating they are the primary site of chemical weathering for cold desert soils and bedrock; 3) water tracks that drain highland terrains are dominated by humidity-separated brines while water tracks that drain lowland terrains are dominated by marine aerosols; 4) water tracks are the sites of the highest terrestrial soil carbon concentrations and the strongest CO2 fluxes in Taylor Valley and their carbon content increases with soil age, while carbon flux decreases with age. To test these hypotheses the PIs will carry out a suite of field measurements supported by modeling and remote sensing. They will install shallow permafrost wells in water tracks that span the range of geological, climatological, and topographic conditions in Taylor Valley. Multifrequency electromagnetic induction sounding of the upper ~1 m of the permafrost will create the first comprehensive map of soil moisture in Taylor Valley, and will permit direct quantification of water track discharge across the valley. The carbon contents of water track soils will be measured and linked to global carbon dynamics.Broader impacts: Non-science majors at Oregon State University will be integrated into the proposed research through a new Global Environmental Change course focusing on the scientific method in Antarctica. Three undergraduate students, members of underrepresented minorities, will be entrained in the research, will contribute to all aspects of field and laboratory science, and will present results at national meetings.

知识分子的优点：PIS建议使用水轨量化泰勒山谷的山坡水，溶质和碳预算，使用水轨研究近地面地质过程，并挑战浅层地下水的范式是最小或非糖果。水轨是高土壤水分的线性区域，在多年冻土主导的土壤中路线沿浅层地下坡道。将测试四个假设：1）水路是水和溶质传输的重要途径； 2）水跟踪的运输比泰勒山谷中的流相比，溶解的二氧化硅更多，这表明它们是冷沙漠土壤和基岩化学风化的主要地点； 3）排水高地地形的水轨主要由湿度分离的盐水主导，而排水低地的水轨则由海洋气溶胶支配； 4）水轨是泰勒谷地最高的土壤碳浓度和最强的二氧化碳通量的地点，其碳含量随着土壤年龄的增长而增加，而碳通量随着年龄的增长而降低。为了检验这些假设，PI将进行一套通过建模和遥感支持的场测量。他们将在泰勒河谷的地质，气候和地形条件范围内安装浅层冻土井。多频电磁电磁电磁电磁声音的多年冻土〜1 m将创建泰勒山谷中首个综合土壤水分图，并将允许直接量化整个山谷的水轨道排放。水迹土壤的碳含量将被测量并与全球碳动力学联系起来。Broader的影响：俄勒冈州立大学的非科学专业将通过针对南极洲科学方法的新的全球环境变化课程整合到拟议的研究中。三名本科生，分数不足的少数群体的成员将被纳入研究，将为现场和实验室科学的各个方面做出贡献，并将在全国会议上提出结果。