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

南极洲的埃里巴斯火山是目前世界上最南端的活火山，火山两侧完全冰川覆盖，有一个活跃的、长寿的熔岩湖。它是研究岩浆过程的天然实验室，因为它持续的火山活动，位于极端干燥的大气条件下，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，火山脱气通过主火山口和熔岩湖进行，但也像许多火山一样，沿着其侧翼进行。与非冰川火山不同，非冰川火山的侧翼排气通常是扩散的，难以测量，而埃里巴斯上的冰塔和冰洞是活跃排气地点的直接指示器。该项目将调查大约20个冰洞的气体和蒸汽排放情况。初步结果表明，冰洞内气体的组成是岩浆气体和空气的混合物，进一步说，这些气体可能与冰川下面的液体、温暖的热液系统相互作用，并溶解在其中。从火山侧翼排入大气的二氧化碳的量以及热液系统(如果存在)溶解岩浆气体的能力都将被量化。这一结果将对更好地量化冰川火山排放的二氧化碳和其他气体产生影响，这与更好地理解地球历史上的冷期有关，包括可能解释从冷期向暖期的转变。该项目将在火山和热液气体采样和分析、火山二氧化碳排放的测量以及结果解释方面培训一名博士后研究人员。这次探险的图像、概念和数据将用于新墨西哥大学的课堂教学，这是一所少数民族服务机构。对二氧化碳(CO2)、甲烷(CH4)和惰性气体的相对丰度的精确量化将使我们能够描述冰川火山下方液态热液系统的范围和温度分布。这些数据与冰洞中二氧化碳通量的测量相结合，提供了以液体为主的热液系统在深处吸收和封存二氧化碳的过程的信息。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，溶解到液体中的二氧化碳的量，以及从火山侧翼脱气的二氧化碳的最终来源将被评估。这些结果可以提供信息，并改进冰川火山对地球大气的火山二氧化碳贡献的模型。除了培训一名博士后，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效果。UNM是一个少数族裔占多数的机构，被联邦归类为拉美裔服务机构。因此，来自不同文化背景的本科生中，有较大比例的人参加了入门课程，并将接触到这些教材。

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.