Collaborative Research: NSFGEO-NERC: Mechanisms of deformation through a complete eruption cycle of Sierra Negra volcano, Galapagos Islands

合作研究：NSFGEO-NERC：加拉帕戈斯群岛内格拉火山完整喷发周期的变形机制

• 批准号: 2122745
• 负责人: Patricia Gregg
• 金额: $ 9.62万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2122745&HistoricalAwards=false
• 关键词: Collaborative; Research; NSFGEO; NERC; Mechanisms

This is a project that is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (UKRI/NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own investigators and component of the work.Volcanic calderas are some of the most awe-inspiring geologic features on earth. Calderas most often form through the withdrawal of magma through eruption and/or intrusion along rift zones, and collapse of the overlying crust. The 2018 eruption of Kilauea volcano, Hawaii was an excellent example of this. In some cases, however, calderas grow through resurgence. Sierra Negra volcano in the Galapagos Islands, is a large basaltic caldera that has grown through resurgence during its last two eruptions. This study will integrate new and existing Global Positioning System (GPS) precise positioning data with seismic data to investigate pre-, co- and post-eruptive processes. This will improve our understanding of the magmatic and volcanic processes that lead to caldera deformation and the processes that potentially trigger volcanic eruptions. Understanding these processes is important for volcanic hazard assessments not only in the Galapagos, but at caldera systems globally, for example, Kilauea volcano, Hawaii. This project will train the next generation of volcano geophysicists, and continue long-standing collaborations between US, UK, and Ecuadorian scientists. This project would not be possible without the partnership with NERC, who has funded the development of the seismic network and data analyses at Sierra Negra volcano.Sierra Negra volcano, in the Galápagos Islands of Ecuador, is one of the largest basaltic calderas on Earth, measuring 9 km by 7 km. Through investments from the NSF RAPID and NERC Urgency programs, the June 26-August 30, 2018 eruption of Sierra Negra was the first eruption at a Galápagos Islands volcano to be recorded by a local geophysical monitoring network. The resulting data are spectacular. The eruption involved 6.5 m of pre-eruptive inflation, formation of a ~12 km long fissure system on the north flank, ~8.5 m of co-eruptive deflation (one of the largest co-eruptive displacements ever observed without collapse on caldera-bounding ring faults), and ~1.5 m of net uplift (resurgence) on the intra-caldera trapdoor fault system. Hundreds of thousands of earthquakes accompanied the pre- and co-eruptive phases, including inflationary and deflationary intra-caldera ‘trapdoor’ faulting events up to Mw5.4. The NSFGEO-NERC collaborative scheme is ideally suited to bring together unique, complementary geodetic and seismic observations and sophisticated numerical modeling techniques to address specific questions relating to the behavior of Sierra Negra, the nature of Galápagos volcanism, and important outstanding questions about fundamental volcano deformation and the interaction between a volcanic edifice and magma plumbing system. The exceptional new geodetic and seismic observations from Sierra Negra offer a unique opportunity to investigate the external and internal deformation of a magmatic system at different stages of unrest. It is rare that a volcanic system is monitored well- and long-enough to observe a complete eruptive sequence from pre-eruptive inflation, magma migration and eruption onset, to co-eruptive deflation, and a return to inflation. By linking observations, through modeling, to changes in pressure and stress within the volcanic system, we will be able to probe the magmatic and structural processes that control magma accumulation and withdrawal, and the initiation of eruptive activity.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.

该项目由美国国家科学基金会地球科学理事会（NSF/GEO）和英国国家环境研究委员会（UKRI/NERC）通过NSF/GEO-NERC牵头机构协议共同资助。该协议允许美国/英国提交一份联合提案，并由其调查员拥有最大比例预算的机构进行同行评审。在成功地共同确定一项奖励后，每个机构为预算的比例和与自己的调查人员有关的调查人员和工作的组成部分提供资金。火山口是地球上最令人敬畏的地质特征之一。火山口通常是由于岩浆通过喷发和/或沿裂谷带的侵入而撤退，以及上覆地壳的崩塌而形成的。2018年夏威夷基拉韦厄火山爆发就是一个很好的例子。然而，在某些情况下，火山口通过复苏而生长。塞拉内格拉火山位于加拉帕戈斯群岛，是一个巨大的玄武岩火山口，在最近两次喷发中复苏。本研究将整合新的和现有的全球定位系统（GPS）精确定位数据与地震数据，以研究火山爆发前、喷发期间和喷发后的过程。这将提高我们对岩浆和火山过程的理解，这些过程导致火山口变形，并可能引发火山爆发。了解这些过程不仅对加拉帕戈斯群岛的火山危险评估很重要，而且对全球的火山口系统也很重要，例如夏威夷的基拉韦厄火山。该项目将培养下一代火山地球物理学家，并继续美国、英国和厄瓜多尔科学家之间的长期合作。如果没有与NERC的合作，这个项目是不可能实现的，NERC资助了Sierra Negra火山地震网络和数据分析的发展。塞拉内格拉火山位于厄瓜多尔Galápagos群岛，是地球上最大的玄武岩火山口之一，长9公里，宽7公里。通过NSF RAPID和NERC紧急项目的投资，2018年6月26日至8月30日塞拉内格拉火山的喷发是当地地球物理监测网络记录的Galápagos群岛火山的第一次喷发。得到的数据是惊人的。这次喷发包括6.5米的喷发前膨胀，在北坡形成了一个~12公里长的裂缝系统，~8.5米的共喷发收缩（在火山口边界环断层上观测到的最大的共喷发位移之一），以及~1.5米的火山口内活门断层系统的净隆起（复苏）。数十万次地震伴随着喷发前和共喷发阶段，包括高达Mw5.4的火山口内“活板门”断层事件的通货膨胀和通货紧缩。NSFGEO-NERC合作计划非常适合将独特的、互补的大地测量和地震观测以及复杂的数值模拟技术结合在一起，以解决与Sierra Negra的行为有关的具体问题，Galápagos火山活动的性质，以及关于基本火山变形和火山大厦与岩浆管道系统之间相互作用的重要突出问题。在Sierra Negra进行的特殊的新大地测量和地震观测为研究岩浆系统在不同动荡阶段的外部和内部变形提供了独特的机会。对一个火山系统进行充分和长期的监测，以观察到一个完整的喷发序列，从喷发前的膨胀，岩浆迁移和喷发开始，到共同喷发的收缩，再到恢复膨胀，这是罕见的。通过建模，将观测结果与火山系统内压力和应力的变化联系起来，我们将能够探测控制岩浆聚集和撤离以及爆发活动开始的岩浆和结构过程。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。