EAPSI: Investigating large, explosive volcanic eruption in the Chilean Andes

EAPSI：调查智利安第斯山脉的大型火山喷发

• 批准号: 1414759
• 负责人: Nathan Andersen
• 金额: $ 0.51万
• 依托单位: Andersen Nathan L
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1414759&HistoricalAwards=false
• 关键词: EAPSI; Investigating; large; explosive; volcanic

The Laguna del Maule volcanic field, located in central Chile, is currently uplifting at a rate among the fastest ever measured at a volcano that is not actively erupting. For the last 20 thousand years, volcanism at Laguna del Maule has been dominated by rhyolite, an uncommon volcanic rock that commonly erupts explosively. The distribution and compositions of recent rhyolites suggest that they are the product of a large, shallow magma reservoir that persists to this day. To understand the relationship between the ongoing uplift and a future potentially large, explosive eruption, it is critical to characterize the magma dynamics that preceded the most recent volcanism. The composition of minerals crystallized in the most recent rhyolites record the changing temperature, pressure, and chemistry of the Laguna del Maule magma reservoir. This research will consist of measuring compositional variation within individual crystals and utilizing numerical models to estimate the timing of the changes in the state of the magma reservoir relative to the subsequent eruption. This research will be performed at the Nanyang Technological University in Singapore in collaboration with Dr. Fidel Costa, a pioneer in applying these numerical modeling techniques. Plagioclase and quartz compositions will be measured using electron microprobe and LA-ICP-MS. The measurement of multiple trace elements with varying diffusivities will provide the most accurate relative ages. The intrusion of mafic magma into the shallow silicic magma system at Laguna del Maule could potentially have imparted the observed mineral zonation, triggered the recent eruptions, and be driving the ongoing unrest. Understanding the dynamic response to such and event is critical to assessing the volcanic hazard at Laguna del Maule and the assembly and eventual eruptions of voluminous rhyolitic magma reservoirs. This NSF EAPSI award is funded in collaboration with the National Research Foundation of Singapore.

位于智利中部的拉古纳德尔马乌莱火山区目前正在以有史以来最快的速度上升，这是在一座没有活跃喷发的火山上测量到的。在过去的两万年里，拉古纳德尔马乌莱的火山活动主要是流纹岩，一种罕见的火山岩，通常爆发。现代流纹岩的分布和成分表明，它们是一个大而浅的岩浆库的产物，一直持续到今天。为了了解正在进行的隆起和未来潜在的大爆发之间的关系，描述最近火山活动之前的岩浆动力学是至关重要的。在最近的韵律中结晶的矿物成分记录了拉古纳德尔马乌莱岩浆库的温度、压力和化学性质的变化。这项研究将包括测量单个晶体内的成分变化，并利用数值模型来估计岩浆库相对于随后喷发的状态变化的时间。这项研究将在新加坡的南洋理工大学与Fidel Costa博士合作进行，Fidel Costa博士是应用这些数值模拟技术的先驱。斜长石和石英成分将使用电子探针和LA-ICP-MS测量。多种微量元素的测量与不同的扩散率将提供最准确的相对年龄。基性岩浆侵入拉古纳德尔马乌莱的浅火山岩浆系统，可能会影响观察到的矿物分带，引发最近的火山爆发，并推动持续的动荡。了解对此类事件的动态响应对于评估拉古纳德尔马乌莱的火山危险以及大量流纹岩岩浆库的聚集和最终喷发至关重要。这个NSF EAPSI奖是与新加坡国家研究基金会合作资助的。