Collaborative research: Dynamics and origins of explosive silicic volcanism at 2300 mbsl on a mid-ocean spreading center

人们对深海环境中的爆炸性硅火山喷发知之甚少，因为发现和记录的火山喷发太少了。在陆地上，这些类型的喷发对火山附近和/或任何火山灰云扩散带沿途的居民构成重大威胁。这项研究分析了2012年蒙特雷湾水族馆研究所（MBARI）前往加利福尼亚湾Alarcon隆起的巡航样本，发现了一个独特的硅（流纹岩、英安岩、安山岩）喷发中心，位于海平面以下2300至2400米。这项研究的目标是填补我们对深海火山爆发事件的理解的主要空白。工作包括收集喷发中心挥发性和脱气历史的综合地球化学、岩石学和火山学数据集。它将涉及合并从该地区高分辨率（1米）水深图获得的地形/特征信息，并分析6个火山碎屑勺袋和24个包含浮石和流体硅材料样本的推岩心。数据将用于确定岩浆分异和挥发性富集机制，以及火山碎屑输运过程、火山碎屑扩散程度和破碎机制。通过测量喷发玻璃中的挥发物（H2O、CO2、S等）含量，确定岩浆挥发物对深海爆炸喷发中岩浆粘度和喷发方式的影响程度。此外，将进行U-Th和U-Th/He和Ar年龄测定，以确定这些沉积物是否代表不止一次喷发，如果不止一次喷发，则确定它们发生的时间。将分析收集到的熔岩和玻璃的稳定同位素（O和H）和放射性成因同位素（Sr, Nd, Pb, Hf），以研究火山爆发起源中潜在的大陆和海洋地壳同化的影响。研究的广泛影响是强大的和多方面的。其中包括为教育工作者创建一个网站和虚拟现实展示研究区域及其火山和火山沉积物，并在YouTube和蒙特雷湾水族馆研究所开放日上分发这些视觉效果。与墨西哥和澳大利亚的科学家也有重要的国际合作；通过在加州大学圣克鲁斯分校开发新的地球化学分析程序和能力，将增加科学基础设施。其他影响是，该项目支持两名早期职业生涯的pi，其中一人在EPSCoR州（罗德岛州）的一所机构。

Very little is known about explosive silicic volcanic eruptions in deep sea environments because so few have been discovered and documented. On land these types of eruptions pose significant hazards for populations living near the volcano and/or along the path of any ash cloud dispersal zone. This research analyzes samples from a 2012 Monterrey Bay Aquarium Research Institute (MBARI) cruise to the Alarcon Rise in the Gulf of California that discovered a unique silicic (rhyolite, dacitic, andesitic) eruption center lying 2,300 to 2,400 meters below the sea surface. Goals of the research are to fill a major gap in our understanding of deep marine explosive volcanic events. Work includes collection of a comprehensive geochemical, petrological, and volcanological dataset of the volatile and degassing history of the eruptive center. It will involve merging topographic/feature information obtained from high resolution (1 meter) bathymetric maps of the area and analyses of 6 volcaniclastic scoop bags and 24 push cores that contain samples of pumice and fluidal silicic material. Data will be used to determine the mechanism of magmatic differentiation and volatile enrichment, as well as volcaniclastic transport processes, pyroclast dispersal extent, and fragmentation mechanisms. It will also determine how much magmatic volatiles influence magma viscosity and eruption style in deep sea explosive eruptions by measuring the volatile (H2O, CO2, S, etc.) contents in the eruptive glasses. Additionally, U-Th and U-Th/He and Ar age dating will take place to determine if the deposits represent more than one eruption and, if there is more than one, when they took place. Both stable isotopes (O and H) and radiogenic isotopes (Sr, Nd, Pb, Hf) of the collected lavas and glasses will be analyzed to examine impacts of potential continental and oceanic crustal assimilation in the origination of the eruption(s). Broader impacts of the research are strong and multifaceted. They include the creation of a website and virtual reality displays of the study area and its volcano and volcanic deposits for educators and the distribution of this visual over YouTube and at the Monterrey Bay Aquarium Research Institute Open House. There is also significant international collaboration with scientists from Mexico and Australia; and there will be an increase in the infrastructure for science by developing new geochemical analytical procedures and capabilities at the University of California, Santa Cruz. Additional impacts are that the project supports two early career PIs, one of whom is at an institution in an EPSCoR state (Rhode Island).