Evaluating the causes of protracted explosive eruptions at Kilauea Volcano, Hawaii

在过去的2500年里，基拉韦厄火山(夏威夷)经历了几个世纪之久的主要爆炸性喷发活动。在2018年火山口坍塌后，东裂谷地带出现了大量熔岩涌出，并转向爆炸行为。研究人员认为，这些事件之间的联系是过去发生的一种趋势，可能会重演。工作将包括橄榄石地球化学和扩散计时学，以解决三个问题：1)在基拉韦厄火山向爆炸阶段过渡的过程中，地壳和地幔输入的作用是什么？2)破火山口坍塌对系统的影响是什么，对随后喷发的管道有什么影响？3)从喷发到以爆炸为主的转变发生在什么时间尺度上？该项目将为早期职业研究人员提供在学术机构管理和运行大型研究项目的经验。将通过非营利性项目Skype a Science开发关于喷发的练习，供K-12课堂期间使用，将STEM浓缩带到全国各地的学校。该项目将强调推进对爆炸性火山喷发的科学理解，以更好地评估这类喷发行为的潜在危险。最后，这些数据将为夏威夷未来的爆炸性喷发提供喷发前的预警信号，进一步发展地球化学法作为监测和预测工具的潜力。从公元前1500年到现在，矿物和熔岩地球化学的重复模式表明，爆发期受根本不同于热液期的地壳过程控制，并与玄武岩破火山口坍塌旋回密切相关。该项目将通过检查来自Uwekahana火山灰的熔岩和火山灰的地球化学性质来调查基拉韦厄火山长期爆炸的原因，Uwekahuna Ash是1200年的爆炸活动期。矿物成分和分带模式将被用来确定岩浆混合和储存的时间尺度。玻璃主量元素和微量元素地球化学将用于表征地幔来源成分、部分熔融和岩浆进入火山系统的流量。结合现有的跨越1500年至今的喷发数据集，这些分析将用于寻找-并评估-在过去2500年的地球化学记录中的重复模式。这一奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

In the past 2,500 years, Kilauea Volcano (Hawaii) has had several centuries-long periods of dominantly explosive eruptive activity. After the after the 2018 caldera collapse, there were large lava flow outpourings at the East Rift Zone and a shift to explosive behavior. Researchers see the connection between those events as a trend that occurred in the past and may repeat. Work will include olivine geochemistry and diffusion chronometry to address three questions: 1) what is the role crustal versus mantle inputs in the transition to an explosive phase at Kilauea? 2) what is the effect of caldera collapse on the system on the plumbing feeding subsequent eruptions? 3) over what time scale does the transition from effusive to dominantly explosive eruptions take place? This project will provide an early career researcher with experience managing and running a large research project at an academic institution. Exercises will be developed on effusive vs. explosive eruptions for use during K-12 classroom sessions through the non-profit program Skype a Scientist, bringing STEM enrichment to schools across the country. This project will emphasize advancing scientific understanding of explosive volcanic eruptions to better evaluate hazard potentials for this type of eruptive behavior. Finally, these data will inform on pre-eruptive warning signs for future explosive eruptions in Hawaii, further developing the potential for geochemical methods to be used as monitoring and predictive tools. Repeated patterns in mineral and lava geochemistry from 1500 C.E. to present suggest that explosive periods are controlled by fundamentally different crustal processes than effusive periods and are intimately linked to cycles of basaltic caldera collapse. This project will investigate the causes of protracted explosive volcanism at Kilauea by examining the geochemistry of lavas and tephra from the Uwekahuna Ash, a 1200-year period of explosive activity. Mineral compositions and zoning patterns will be used to determine the timescales of magma mixing and storage. Glass major and trace element geochemistry will be used to characterize mantle source composition, partial melting, and the flux of magma into the volcanic system. Combined with existing datasets for eruptions spanning 1500-present day, these analyses will be used to look for – and evaluate the causes of – repeating patterns in the geochemical record over the past 2,500 years.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.