Integrated Petrologic and Volcanologic Studies of the 1991 Eruption of Hudson Volcano

0337023智利哈德逊火山1991年喷发是20世纪最大的喷发事件之一，火山爆炸性指数为5。这次喷发横穿了破火山口顶端的一条厚厚的冰川，导致了显著的岩浆和水的相互作用。这项工作的目标将是调查1991年喷发的不同岩浆成分(玄武岩、粗安岩和流纹岩)之间的关系，并确定喷发前岩浆系统的压力、温度和挥发条件。为了研究潜在的破碎模式，将使用分形分析和泡孔指数来定量表征颗粒的形貌。颗粒大小和扩散特征的测量将与喷发柱高度的观测结合使用，以评估经常用于重建古代喷发动力学的火山喷发扩散理论模型的有效性。整个项目的目的是1)更详细地了解1991年哈德逊火山喷发的火山过程，2)研究冰川融水对喷发的潜在影响，3)根据喷发产物的岩石学和地球化学特征建立哈德逊之下岩浆系统的模型，4)测试现有的特弗拉坠落模型。就更广泛的影响而言，该项目将涉及美国和阿根廷的研究生的参与，因此将成为一次宝贵的交流经验。此外，一个重要的目标将是通过这项合作研究在阿根廷培养更多对火山学研究的兴趣。私家侦探将通过一个网站向公众分享在哈德逊获得的信息，该网站旨在突出与这座火山相关的历史、活动和危险。研究成果还将纳入私人投资机构在各自机构教授的本科生和研究生课程。

CareyEAR 0337023 The 1991 eruption of Hudson volcano in Chile was one of the largest explosive events of the twentieth century with a Volcanic Explosivity Index (VEI) of 5. The eruption transected a thick glacier in the summit caldera resulting in significant magma/water interactions. The objectives of the work will be to investigate the relationship between the different magma compositions erupted in 1991 (basalt, trachyandesite and rhyolite) and define the pressure, temperature and volatile conditions of the magmatic system prior to eruption. In order to investigate potential modes of fragmentation, particle morphologies will be quantitatively characterized using fractal analysis and vesicularity indices. Measurements of grain size and dispersal characteristics will be used in conjunction with observations of eruption column height to evaluate the effectiveness of theoretical models for tephra dispersal that are often used to reconstruct the dynamics of ancient eruptions. The overall project is intended to 1) provide a more detailed understanding of the volcanological processes of the 1991 Hudson eruption, 2) examine the potential effects of glacial meltwater on the eruption, 3) develop a model for the magmatic system beneath Hudson based on the petrologic and geochemical features of the erupted products and 4) test existing tephra fallout models. In terms of broader impacts, the project will involve the participation of graduate students in both the United States and Argentina and will thus serve as a valuable exchange experience. In addition, an important objective will be to foster more interest in volcanological research in Argentina through this collaborative research. The P.I.s will share the information gained at Hudson to the general public via a website constructed to highlight the history, activity, and hazards associated with this volcano. Research results will also be integrated into undergraduate and graduate courses taught by the P.I.s at their respective institutions.