Erebus Volcano: Ccharacterizing a Subglacial Hydrothermal System and Potential effects on Carbon Dioxide Degassing

埃里伯斯火山：冰下热液系统的特征及其对二氧化碳脱气的潜在影响

• 批准号: 1443633
• 负责人: Tobias Fischer
• 金额: $ 28.04万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1443633&HistoricalAwards=false
• 关键词: Erebus; Volcano; Ccharacterizing; Subglacial; Hydrothermal

Erebus Volcano, Antarctica, is the world's southernmost currently active volcano, with fully glaciated flanks, and an active, long-lived lava lake. It is a natural laboratory for the study of magmatic processes due to its consistent volcanic activity, location in an area with extremely dry atmospheric conditions, lack of liquid water at the surface, and superb logistical support. As such, it is the ideal place to investigate magma degassing. At Erebus volcanic degassing occurs through the main crater and lava-lake but also, as at many volcanoes, along its flanks. In contrast to non-glaciated volcanoes where flank degassing is often diffuse and difficult to measure, the ice-towers and ice caves on Erebus are direct indicators of sites of active degassing. This project will investigate gas and steam discharges in approximately 20 ice caves. Preliminary results show that the composition of gases within the ice caves is a mixture of magmatic gases and air, and further that the gases are likely interacting with, and dissolving in, a liquid, warm, hydrothermal system below the glacier. The amount of carbon dioxide degassing from the volcano's flanks to the atmosphere and the ability of the hydrothermal system (if present) to dissolve magmatic gases will both be quantified. The results will have implications for better quantifying carbon dioxide and other gas emissions from glaciated volcanoes, which is relevant for better understanding of colder periods in Earth's history, including potentially explaining the transition from colder periods to warmer ones. The project will train a post-doctoral researcher in volcanic and hydrothermal gas sampling and analyses, measurements of carbon dioxide emissions from the volcano, and interpretation of the results. Images, concepts, and data from the expedition will be used in classroom teaching at the University of New Mexico, a minority serving institution.The precise quantification of the relative abundances of carbon dioxide (CO2), methane (CH4), and the noble gases will allow us to characterize the extent and temperature distribution of the liquid hydrothermal system below the glaciated volcano. Combination of these data with measurement of CO2 flux in the ice caves provides information on the processes of CO2 absorption and sequestration by the liquid-dominated hydrothermal system at depth. By applying geochemical techniques and modeling, the temperature, pH, and volatile content of the hydrothermal system can be determined, the amount of CO2 that dissolves into the liquid phase, and the ultimate source of the CO2 that is degassing from the volcano's flanks will be assessed. These results can inform, and improve, models of volcanic CO2 contributions to the Earth's atmosphere from glaciated volcanoes. In addition to training a post-doc, outreach efforts will include utilization of materials and visuals for introductory Geology and volcanology classes. UNM is a majority-minority institution and federally classified Hispanic-serving institution. Therefore, a comparatively large proportion of undergraduates from culturally diverse backgrounds take introduction classes and will be exposed to these teaching materials.

南极洲的埃里伯斯火山是目前世界上最南端的活火山，其侧翼完全被冰川覆盖，还有一个活跃、长寿的熔岩湖。它是研究岩浆过程的天然实验室，因为它的火山活动持续不断，位于一个大气条件极其干燥的地区，地表缺乏液态水，以及一流的后勤支持。因此，它是研究岩浆脱气的理想场所。 在埃里伯斯，火山的排气作用通过主火山口和熔岩湖发生，但也像许多火山一样，沿着它的两侧沿着发生。在非冰川作用的火山中，侧翼的脱气作用通常是分散的，难以测量，而埃里伯斯的冰塔和冰洞则是活跃脱气作用的直接指示。 该项目将调查大约20个冰洞中的气体和蒸汽排放。 初步结果表明，冰洞内的气体成分是岩浆气体和空气的混合物，而且这些气体可能与冰川下方的液体、温暖的热液系统相互作用并溶解在其中。从火山侧翼到大气中的二氧化碳脱气量以及热液系统（如果存在）溶解岩浆气体的能力都将被量化。 这些结果将对更好地量化冰川火山的二氧化碳和其他气体排放产生影响，这与更好地了解地球历史上的寒冷时期有关，包括可能解释从寒冷时期到温暖时期的过渡。 该项目将培训一名博士后研究员，从事火山和热液气体取样和分析、火山二氧化碳排放量测量以及结果解释等方面的工作。 图像，概念和数据的探险将用于课堂教学的新墨西哥州，少数民族服务机构。二氧化碳（CO2），甲烷（CH 4），和惰性气体的相对丰度的精确量化将使我们能够描述的范围和温度分布的液态热液系统下面的冰川火山。 这些数据与冰洞中CO2通量的测量相结合，提供了有关深部以液体为主的热液系统吸收和封存CO2过程的信息。通过应用地球化学技术和建模，可以确定热液系统的温度，pH值和挥发物含量，溶解到液相中的CO2的量，以及从火山侧翼脱气的CO2的最终来源。这些结果可以为冰川火山对地球大气层的火山二氧化碳贡献模型提供信息，并加以改进。除了培训博士后外，外联工作还将包括利用地质学和火山学入门课程的材料和视觉材料。 UNM是一个少数民族占多数的机构和联邦分类的西班牙裔服务机构。因此，来自不同文化背景的大学生中有相当大的比例参加了入门课程，并将接触到这些教材。