Collaborative Research: High resolution passive seismic imaging beneath Valles Caldera

合作研究：Valles Caldera 下方的高分辨率被动地震成像

• 批准号: 2113315
• 负责人: Brandon Schmandt
• 金额: $ 10.64万
• 依托单位: University of New Mexico
• 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: 2021-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2113315&HistoricalAwards=false
• 关键词: Collaborative; Research; resolution; passive; seismic

The Valles caldera is one of three supervolcanoes in North America and has a long history of volcanism with documented magma flows as recent as ~70,000 years. Seismic imaging allows visualization of volcanic subterranean structures by using seismic waves in a similar way ultrasound sonography in medical imaging. Seismic imaging of the Valles Caldera was lacking until recently, which in turn has hindered estimate of melt volumes, melt extent, and understanding of the plumbing system. A joint University of Texas at El Paso (UTEP)/University of New Mexico (UNM) deployment in 2019 resulted in a 97-seismometer line crossing the entire caldera for 1 month. A primary objective of this initiative is to resolve the spatial extent and concentration of melt under the caldera, with other standing questions including the depth of any magma body underlying the dome, the thickness of intra-caldera fill and fractured basement blocks, and the nature of the crust/mantle boundary. Using cutting edge techniques, researchers probe and unveil the subterranean magmatic system of the volcano and foster a collaboration between UTEP and UNM, two minority serving institutions. The outcomes of this project improve earthquake and volcanic hazard assessment in the region, and support the training of graduate and undergraduate students from underrepresented minorities in science. The Valles caldera, a Quaternary-active supervolcanoes, is the textbook example of a resurgent caldera. It has largely escaped seismic scrutiny in the past two decades. Here the researchers probe the magmatic system beneath Valles caldera. They quantify the spatial extent of melt structures, the depth and emplacement of scattering boundaries, and assess the assumed aseismic nature of the caldera system. Ambient noise seismic interferometry is leveraged to estimate dispersion curves for long period Rayleigh and Love waves; these will be jointly inverted in a transdimensional Bayesian scheme with receiver functions, H/V ratios, and noise autocorrelations. The goal is to accurately estimate velocity structures under the Valles caldera. Targets include bounding the spatial extent and concentration of melt through shear-wave velocity and Vp/Vs estimates, depth to magmatic structures and caldera fill under the resurgent dome through scattered wave analysis, and detection and location of any local seismicity that may reveal magma and fluid movements. This project complements sparser long-term seismic monitoring efforts by Los Alamos National laboratory. It serves as an educational primer and complement to frequent geophysics field camps using the caldera as a natural laboratory. Its outcomes improve the assessment of the volcano life-cycle stage and allow better comparison with other Quaternary supervolcanoes.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.

Valles Caldera是北美的三个超级火山之一，在近期约70,000年的岩浆流中有悠久的火山史。地震成像可以通过在医学成像中以类似的超声超声检查方式使用地震波来可视化火山地下结构。 直到最近才缺乏对Valles火山口的地震成像，这反过来又阻碍了对管道系统的熔体体积，熔体范围和理解的估计。 德克萨斯州埃尔帕索（UTEP）联合大学/新墨西哥大学（UNM）部署于2019年成立了一条97-看语表线，越过整个火山口1个月。 该计划的主要目的是解决火山口下的空间范围和融化的融化，以及其他站立的问题，包括圆顶上的任何岩浆体的深度，圆顶内部填充物的厚度和破裂的地下室块，以及地壳/甲壳虫边界的性质。研究人员使用尖端技术探测并揭示了火山的地下岩浆系统，并促进了UTEP与UNM之间的合作，这是两个少数派服务机构。 该项目的结果改善了该地区的地震和火山危害评估，并支持培训来自代表性不足的科学少数群体的研究生和本科生。 Quaternary-Active Supervolcanoes Valles Caldera是复兴火山口的教科书示例。在过去的二十年中，它在很大程度上逃脱了地震审查。在这里，研究人员探究了Valles火山口下的岩浆系统。 它们量化了熔体结构的空间范围，散射边界的深度和降级，并评估Caldera系统的假定无性性质。环境噪声地震干涉测量法可以估算长期雷利和爱情波的分散曲线；这些将在具有接收器函数，H/V比和噪声自相关的跨维贝叶斯方案中共同反转。 目的是准确估计Valles火山口下的速度结构。目标包括通过剪切波速度和VP/VS估计的空间范围和浓度的限制，深度到岩浆结构到岩浆结构，并通过分散的波浪分析在复兴的圆顶下填充火山口，以及任何可能揭示岩浆和流体运动的局部地震性的检测和位置。该项目补充了洛斯阿拉莫斯国家实验室的长期长期地震监测工作。它是一种教育入门，并补充了使用火山口作为天然实验室的频繁地球物理野外训练营。它的结果改善了对火山生命周期阶段的评估，并允许与其他第四纪超级滑水机进行更好的比较。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子优点和更广泛的影响审查标准来评估NSF的法定任务。

项目成果

Shear Velocity Evidence of Upper Crustal Magma Storage Beneath Valles Caldera

火山口山谷下上地壳岩浆储存的剪切速度证据

• DOI: 10.1029/2022gl101520
• 发表时间: 2023
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Wilgus, Justin;Schmandt, Brandon;Maguire, Ross;Jiang, Chengxin;Chaput, Julien
• 通讯作者: Chaput, Julien