Collaborative Research: Caldera Dynamics and Eruption Cycles at Axial Seamount

合作研究：轴向海山的火山口动力学和喷发周期

• 批准号: 1950996
• 负责人: William Wilcock
• 金额: $ 41.13万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-15 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1950996&HistoricalAwards=false
• 关键词: Collaborative; Research; Caldera; Dynamics; Eruption

Volcanic eruptions are one of the most important processes that shape the Earth’s surface. However, eruptions are difficult to study up close because they are so destructive. The deep seafloor provides an opportunity to collect detailed observations of eruptions immediately atop a volcano. Since 2014, the NSF Ocean Observatories Initiative has operated a cabled observatory in the southern half of the summit caldera of Axial Seamount, an active volcano located 300 miles off the coast of Oregon. In 2015, the volcano erupted and the records from cabled instruments provided many insights. Among these insights were improvements in forecasting eruptions. Axial Seamount is rapidly inflating, and another eruption is now predicted in a few years. This proposal will operate 15 remote seafloor instruments for earthquake detection. Over 2 years the project will seek to record the next eruption. These new observations will improve understanding of how magma and fractures interact in volcanoes. Such interactions create the pathways of magma to the seafloor. This experiment is part of a broader effort in the volcano science community to develop Community Experiments. These experiments include different kinds of eruptions. Through the comparison of the different eruptions scientists will improve the understanding of volcano hazards. The data from this project will be available to all of the public. Among the science community this data sharing will help scientists interpret geological, hydrothermal and biological observations from submarine volcanoes.Axial Seamount is a submarine volcano at the intersection of the Cobb hotspot and the Juan de Fuca ridge that erupted in 1998, 2011 and 2015. The 2015 eruption was captured in real time by the instrumentation on Ocean Observatories Initiative (OOI) Cabled Array shortly after the observatory came online. The geophysical observations yielded new insights into eruption forecasting, the dynamics of caldera ring faults, and the generation of explosive signals on the seafloor as lava erupts. However, the small footprint of the 7-station cabled seismic network limited the spatial extent of well-resolved earthquake locations to the southern portion of the caldera and the short duration of observations prior to the eruption complicated the search for precursory signals. As a result, there are unresolved questions related to the dynamics of the northern caldera, the interactions of the caldera ring faults and eruptive rifts, the impacts of magmatic processes during eruption cycle on the time-dependent seismic structure of the upper crust, and the links to deeper magmatic processes. This project will support a 2-year field experiment in the predicted time window of the next eruption that will deploy 15 autonomous ocean bottom seismographs (OBS) to extend seismic coverage of the cabled network to cover the whole caldera and portions of the south and north rifts. The open access data will be used to create earthquake catalogs and support a variety of studies to constrain the dynamics of the whole caldera, characterize the interaction the eruptive dikes with the caldera, observe the spatiotemporal evolution of shallow magmatic and tectonic process and search for signals associated with deeper magmatic processes. It will address three hypotheses, that: 1) magmatic processes related to the shallow reservoir exert primary control on caldera and rift structure; 2) the complex shallow reservoir geometry reflects and affects the evolution of magma transport and storage; and 3) magma from the deeper part of the system can be rapidly mobilized and interact with the shallow reservoir over short timescales (weeks/months).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.

火山喷发是塑造地球表面的最重要过程之一。但是，喷发很难近距离研究，因为它们是如此具有破坏性。深处的海底提供了一个机会，可以立即在火山上收集详细的爆发观察。自2014年以来，NSF海洋天文台倡议在Axial Seamount的Summit Caldera的南半部经营着一个有线的观测，这是一个距离俄勒冈州海岸300英里的活火山。 2015年，火山爆发了，Cabled乐器的记录提供了许多见解。这些见解包括预测喷发的改善。轴向海山正在迅速膨胀，现在预计几年后会进行另一次喷发。该提案将运行15种偏远海底仪器进行地震检测。该项目将在2年的时间内试图记录下一次爆发。这些新的观察结果将提高人们对岩浆和裂缝在火山中的相互作用的理解。这种相互作用创造了岩浆到海底的途径。该实验是火山科学界为开发社区实验的更广泛努力的一部分。这些实验包括不同种类的喷发。通过比较不同的爆发，科学家将改善对火山危害的理解。该项目的数据将向所有公众提供。在科学界，这个数据共享将帮助科学家解释海底火山的地质，水热和生物学观察。轴向封口是在Cobb Hotspot和Cobb Hotscot和Juan de Fuca Ridge的交汇处的一座海底火山，该山脉在1998年，2015年和2015年爆发了仪器（2015年爆发）。观察性上网后不久，阵列。地球物理观测产生了有关喷发预测，火山口戒指断层的动力学以及随着熔岩喷发在海底上的爆炸信号的产生的新见解。然而，7个站有线地震网络的较小占地面积限制了良好的地震位置的空间范围，到火山口的南部，并且在爆发之前的观察持续时间短，使搜索前体信号的搜索变得复杂。结果，存在与北部火山口的动力学有关的问题，火山口环和喷发裂痕的相互作用，喷发周期期间岩浆过程对上皮的时间依赖性地震结构的影响以及与更深岩浆过程的链接。该项目将在下一次喷发的预测时间窗口中支持一项为期两年的现场实验，该实验将部署15个自主海洋底部地震仪（OBS），以扩展有被有线网络的地震覆盖范围，以覆盖整个火山口以及南部和北裂口的整个部分。开放访问数据将用于创建地震目录并支持各种研究，以限制整个火山口的动态，表征与火山口的爆发堤的相互作用，观察浅层岩浆和构造过程的空间时间演变，并搜索与更深层岩浆过程相关的信号。它将解决三个假设，即：1）与浅层储层有关的岩浆过程对火山口和裂谷结构产生主要控制； 2）复杂的浅水储层几何形状反映并影响岩浆运输和存储的演变； 3）从系统较深的部分的岩浆可以在短时间内迅速动员并与浅层储层相互作用（周/月）。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审查标准通过评估来评估的。