Collaborative Research: Linking 3He/4He with eruptive behavior: A time series analysis of recent Kilauea, Iceland, and La Palma eruptions

合作研究：将 3He/4He 与喷发行为联系起来：对近期基拉韦厄火山、冰岛火山和拉帕尔马火山喷发的时间序列分析

• 批准号: 2232532
• 负责人: Marc-Antoine Longpre
• 金额: $ 7.46万
• 依托单位: CUNY Queens College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-15 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2232532&HistoricalAwards=false
• 关键词: Collaborative; Research; Linking; 3He; 4He

Approximately 800 million people live in regions that are directly exposed to volcanic hazards, yet eruptions remain difficult to forecast. In some cases, earthquakes and ground swelling have been used to predict imminent volcanic eruptions. In other instances, changes in volcanic gas emissions have been used to infer changes in volcanic activity because gas emissions are thought to be linked to the ascent of magmas beneath volcanoes preceding eruptions. This project explores the possibility that volcanic gas chemistry might hold vital clues about magma recharge that could help forecast the onset and course of volcanic eruptions. Magmas from the deep Earth are rich in 3He (an isotope of helium that is very rare compared to 4He). Thus, magma recharge events may cause increases in 3He relative to 4He (i.e., higher 3He/4He). This hypothesis will be tested by measuring 3He/4He values in lavas from recent eruptions in Hawai’i, Iceland, and the Canary Islands. By comparing 3He/4He to other volcanic indicators, including lava discharge rate, lava composition, earthquake frequency and magnitude, and other chemical features of volcanic gases detected by satellites, the team will attempt to link changes in 3He/4He to volcanic activity. If helium systematics change in response to potentially hazardous volcanic processes, real-time helium monitoring of volcanoes may be justified. Not only does this project aim to broaden our understanding of volcanic systems, it also emphasizes high school, undergraduate, and graduate education. In partnership with the New Heights Charter School, in Brockton Massachusetts, the science team will develop lectures and activities relating to volcanology. Two undergraduate summer student fellows at Woods Hole Oceanographic Institution will be recruited from City University of New York (CUNY), which has a diverse student population. Two additional CUNY undergraduate students will participate by conducting independent study projects. One graduate student enrolled in the Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program will contribute to all stages of the research. And this work will provide employment for an autistic woman through a partner organization that facilitates rehabilitation for individuals with disabilities.Volcanic hazard forecasting remains a pressing and elusive challenge for the volcanology community. Seismic activity and ground deformation monitoring are often difficult to link with magmatic processes. Integrative monitoring approaches show the most promise, especially those that supplement established techniques with geochemical monitoring. Helium isotopes show great potential in this regard because they (i) are sensitive to recharge events and (ii) can be monitored—in fumaroles, soils, geothermal waters, and lavas—during eruptions and during periods of repose. Furthermore, previous work indicates that helium isotopes (3He/4He) are sensitive to magma recharge events from the mantle. The goal of this project is to assess the causes of 3He/4He variability on timescales of weeks to months in order to determine whether costly real-time helium isotope monitoring efforts would improve volcanic hazard forecasting. This study will produce magmatic 3He/4He time series records for three recent eruptions: the Lower Eastern Rift Zone of Kīlauea in Hawaii (2018), Fagradalsfjall in Iceland (2021), and Cumbre Vieja in the Canary Islands (2021). Magmatic helium will be extracted from clinopyroxene and olivine mineral separates from lava samples spanning each eruption. Comparison of lava 3He/4He, major and trace element abundances, radiogenic isotopes, and remote sensing data—including ground deformation, seismicity, satellite-based SO2 emissions, and lava discharge rates—will establish whether magma recharge is principally responsible for 3He/4He variability. Alternatively, source heterogeneity or lithospheric helium assimilation might be dominant. By investigating multiple well-monitored eruptions, this project will potentially identify common causes of helium isotopic variability during volcanic eruptions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

直接暴露于火山危害的地区，大约有8亿人生活，但爆发仍然很难预测。在某些情况下，地震和地面肿胀已被用来预测迫在眉睫的火山喷发。在其他情况下，火山气体排放的变化已被用来推断火山活动的变化，因为人们认为气体排放与喷发前火山下的岩浆的上升有关。该项目探讨了火山气化学可能对岩浆充电的重要线索，这可能有助于预测火山喷发的发作和过程。来自深地球的岩浆富含3He（与4He相比非常罕见的氦同位素）。那就是岩浆补给事件可能会导致3HE相对于4HE（即3HE/4HE）的增加。该假设将通过测量夏威夷，冰岛和金丝雀群岛最近喷发的熔岩中的3HE/4HE值来检验。通过将3HE/4HE与其他火山指标进行比较，包括熔岩排放率，熔岩成分，地震频率和幅度以及卫星检测到的火山气体的其他化学特征，该团队将尝试将3HE/4HE的变化与火山活动联系起来。如果氦系统对潜在的危险火山过程的响应发生变化，则可以证明对火山火山过程的实时氦气监测是合理的。该项目不仅旨在扩大我们对火山系统的理解，还强调了高中，本科和研究生教育。与马萨诸塞州布罗克顿的新高地特许学校合作，科学团队将开发与火山学有关的讲座和活动。纽约市城市大学（CUNY）将招募伍兹霍尔海洋学机构的两个本科生夏季学生研究员，该大学的学生人数不同。另外两个CUNY本科生将通过进行独立的研究项目参加。马萨诸塞州理工学院洞海洋学机构联合计划的一名研究生将有助于研究的所有阶段。这项工作将通过合作伙伴组织为加速妇女提供就业机会，该组织有助于为残疾人恢复康复。沃尔卡纳克危害预测仍然是火山学界的紧迫和弹性挑战。地震活动和地面变形监测通常很难与岩浆过程联系起来。综合监测方法显示出最大的希望，尤其是那些通过地球化学监测来补充建立技术的方法。在这方面，氦同位素在这方面表现出很大的潜力，因为它们（i）对充电事件敏感，并且可以监测（ii）（在烟草，土壤，地热水和熔岩中）在爆发和休息期间进行监测。此外，以前的工作表明氦同位素（3HE/4HE）对地幔中的岩浆充电事件敏感。该项目的目的是评估数周至数月的时间尺度3HE/4HE变异性的原因，以确定昂贵的实时氦同位素监测工作是否会改善火山危害的预测。这项研究将产生3HE/4HE的时间序列记录，以记录最近发生的三起爆发：夏威夷的基拉伊亚下部裂谷区（2018年），冰岛的Fagradalsfjall（2021）和Canary Islands的Cumbre Vieja（2021）（2021）。岩浆氦将从临床氧烯中提取，橄榄石矿物质与每次喷发的熔岩样品分离。熔岩3HE/4HE，主要和痕量元素丰度，放射异位同位素和遥感数据的比较，包括地面变形，地震性，基于卫星的SO2 SO2排放和熔岩排放率 - 将确定Magma恢复是否主要负责3HE/4HE的可变性。通过调查多次监控爆发，该项目将有可能在火山喷发期间确定氦同位素变异性的共同原因。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响来通过评估来支持的珍贵支持。