Collaborative Research: The Magmatic and Eruptive System of Mount Erebus Volcano, Antarctica

位于南极洲罗斯岛上的埃里伯斯火山至少45年来一直处于持续的火山口活动状态，山顶上有一个长期存在的熔岩湖。该火山靠近美国南极计划麦克默多站，其长期的实验基础设施，以及先前的研究为开发和应用尖端成像方法来了解持续活跃的火山系统提供了机会。该项目将利用埃里伯斯火山近山顶地震网络的五个站点以及火山侧面的三个额外站点的数据。这个大孔径网络，配合现代仪器和技术来增强地震信号，将提供前所未有的成像到地壳尺度的深层火山管道系统，这将有助于研究人员了解火山的复杂结构和过程。此外，该网络提供全年地震数据，用于火山喷发和其他活动的时间监测工作。该网络的所有数据都将近乎实时地公开提供。实时数据以及现有的存档数据目录将使用最近开发的方法进行分析，以概括、识别、量化和编目爆发事件。该项目的目标是研究岩浆系统对此类事件的反应，并使用连续记录的背景噪声和喷发信号来推断同时发生的结构变化。这些对火山长期变化的地震调查，追踪诸如罗斯岛下沉等广泛现象，也将得到GPS变形记录的补充。这些活动将有助于测试与埃里伯斯更深层岩浆系统的结构有关的假设，以及围绕该系统的物质的性质。该项目资助了两名早期职业科学家和三名研究生，为下一代火山学家和地震学家的发展做出了贡献。该合同建立了第一级监测系统，并使用实时地震和次声数据对喷发事件进行分类。通过测量短周期（爆炸）和长周期（管道）地震记录特征的系统时序变化，对更新的地震网络记录的宽带信号进行概要分析，可以监测和解释爆发前后的响应和管道演变。这些观测将得到宽带地震倾斜的解释的补充，这些解释将结合现有的联安办事处支持的GPS数据，时间尺度从小时到年不等。较长周期尾波相关反演将用于提炼上层构造信息，并对远震信号进行分析，以检验下伏地壳的体积和不连续结构。这项工作包括重新分析存档的TOMO Erebus宽带，以及2007-2008年收集的大量短期数据。与之前在埃里伯斯（Erebus）成像的其他限制条件（如埃里伯斯（Erebus）和罗斯岛（Ross Island）的大地电磁成像结果）相比，这一努力将允许对更深层次（例如地壳到莫霍或更深层次）结构进行新的成像和解释。研究人员将使用全年连续的站点来延时查询突出的和可重复的结构/内部散射特征，这些特征是由环境噪声和喷发或其他信号尾波相关性揭示的。尾波和环境噪声的H/V比联合反演，加上由环境噪声（低频）和尾波（高频）融合而成的色散曲线，将补充强近地表散射体的直接成像，并将应用于存档的ETB/ETS数据集。尖端反射矩阵技术将继续与法国独立资助的小组合作，进一步隔离和定义地壳和大厦顶部10公里内的高散射体。该奖项由极端事件预测和恢复能力（PREEVENTS）项目共同资助。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。

Mount Erebus, a volcano on Ross Island, Antarctica has been in a continuous state of open-vent activity for at least 45 years while hosting a long-lived lava lake at its summit. The volcano's proximity to the United States Antarctic Program McMurdo Station, its longstanding experimental infrastructure, and prior studies present opportunities to develop and apply cutting edge imaging methods to understand a persistently active volcanic system. This project will utilize data from a renovated five-station near-summit seismic network of Mt. Erebus plus three additional stations sited on the flanks of the volcano. This wide aperture network, paired with modern instrumentation and techniques to enhance seismic signal, will provide unprecedented imaging into the deep volcanic plumbing system at crustal scale, which will help researchers understand the volcano's complex structure and processes. Additionally, the network provides year-round seismic data to be used in temporal monitoring efforts for eruptive and other activity. All data from this network will be openly available in near real-time. The real-time data along with an existing catalog of archived data will be analyzed using recently developed methods to generalize, recognize, quantify, and catalog eruptive events. The project objectives are to study the response of the magmatic system to such events and use continuously recorded background noise and eruption signals to infer concurrent structural changes. These seismic investigations into the long-term changes of the volcano, tracking broad phenomena such as the subsidence of Ross Island, will also be complemented by GPS recordings of deformation. These activities will help test hypotheses related to the structure of the deeper magmatic system of Erebus and the properties of the material surrounding this system. The project funds two early-career scientists and three graduate students, contributing to the development of the next generation of volcanologists and seismologists.This award results in the establishment of a first-tier monitoring system and catalogues eruptive events using real-time seismic and infrasound data. Synoptic analysis of broadband signals recorded by the updated seismic network will allow monitoring and interpretation of pre and post eruptive response and conduit evolution via measurements of systematic timing changes of short-period (explosion) versus very long-period (conduit) seismogram signatures. These observations will be supplemented by the interpretation of broadband seismic tilt in association with existing UNAVCO-supported GPS data over time scales from hours to years. Longer-period coda correlation back projection will be used to refine upper edifice structural information and teleseismic signals will be analyzed to examine the bulk and discontinuity structure of the underlying crust. The work includes a reanalysis of archived TOMO Erebus broadband, as well as extensive short-period data collected in 2007-2008. This effort will allow new imaging and interpretation of deeper (e.g., crustal to Moho-or-deeper scale) structure than has been previously imaged at Erebus in consort with other constraints, such as emerging magnetotelluric imaging results for Erebus and Ross Island. The researchers will use the year-round continuous stations to time-lapse interrogate prominent and repeatable structural/internal scattering features revealed by both ambient noise and eruption or other signal coda correlations. Joint inversions of H/V ratios for both coda and ambient noise coupled with dispersion curves assembled from the fusion of ambient noise (low frequency) and coda (high frequency) will complement direct imaging of strong near-surface scatterers and will be applied to archived ETB/ETS data sets. Cutting edge reflection matrix techniques will continue to be developed in collaboration with independently funded groups in France to further isolate and define high scattering bodies within the top 10 kilometers of the crust and edifice. This award is cofunded by the Prediction of and Resilience against Extreme Events (PREEVENTS) program.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.