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

合作研究：洋中扩散中心 2300 mbsl 硅质火山喷发的动力学和起源

• 批准号: 1354167
• 负责人: Brian Dreyer
• 金额: $ 14.83万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-15 至 2017-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1354167&HistoricalAwards=false
• 关键词: Collaborative; research; Dynamics; origins; explosive

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).

人们对深海环境中的火山爆发知之甚少，因为很少有人被发现和记录。在陆地上，这些类型的喷发对生活在火山附近和/或任何灰云散布区沿着的人口构成重大危险。这项研究分析了2012年蒙特雷湾水族馆研究所（MBARI）前往加州湾阿拉尔孔隆起的样本，该研究发现了一个位于海面以下2,300至2,400米处的独特的流纹岩（流纹岩，英安岩，安山岩）喷发中心。这项研究的目标是填补我们对深海爆发性火山事件的理解中的一个重大空白。工作包括收集一个全面的地球化学，岩石学和火山喷发中心的挥发性和脱气历史的火山数据集。这将涉及合并从该地区高分辨率（1米）测深图获得的地形/特征信息，并分析6个火山碎屑勺袋和24个含有浮石和流体碎屑样品的推芯。这些数据将用于确定岩浆分异和挥发性富集的机制，以及火山碎屑的迁移过程、火山碎屑的散布程度和碎裂机制。它还将通过测量深海爆炸喷发中的挥发物（H2O、CO2、S等）来确定岩浆挥发物对岩浆粘度和喷发方式的影响程度。玻璃杯里的东西此外，将进行U-Th和U-Th/He和Ar年龄测定，以确定矿床是否代表一次以上的喷发，如果有一次以上，则确定何时发生。将分析收集的熔岩和玻璃的稳定同位素（O和H）和放射性同位素（Sr，Nd，Pb，Hf），以研究潜在的大陆和海洋地壳同化在喷发起源中的影响。研究的更广泛影响是强大和多方面的。其中包括创建一个网站，为教育工作者虚拟现实展示研究区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一视频。还与墨西哥和澳大利亚的科学家进行了重要的国际合作;通过开发新的地球化学分析程序和能力，加州大学圣克鲁斯分校将增加科学基础设施。其他影响是，该项目支持两个早期职业PI，其中一个是在EPSCoR州（罗得岛）的机构。