Collaborative Research: Transport of magma in the near surface at small volcanoes- Experimental intrusion of basaltic melt into unconsolidated sediments

合作研究：小火山近地表岩浆输送——玄武岩熔体侵入松散沉积物的实验

• 批准号: 2032167
• 负责人: Alison Graettinger
• 金额: $ 27.4万
• 依托单位: University of Missouri-Kansas City
• 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: 2021-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2032167&HistoricalAwards=false
• 关键词: Collaborative; Research; Transport; magma; near

This project deals with the interaction of magma and the materials through which it rises to feed small-volume volcanoes (the most abundant volcanic landforms on Earth). When magmatic interaction involves loose sediments that contain variable amounts of water or ice, the magma may behave in a variety of ways - passing through the material, causing explosions or even stopping before reaching the surface. These different behaviors influence how a volcano will erupt, and this project will enhance the ability to anticipate the behavior of future eruptions, which is vital for saving lives and protecting infrastructure. This project involves experiments that will inject 30 liters (8 gallons) of basaltic melt into different types of loose sediment - dry, wet, and frozen. The experiments provide the opportunity to characterize the conditions of magma and sediment interactions that result in these diverse behaviors. Characterization of conditions, which are limited by physical experiments will be expanded using computer simulations and comparison with natural products from an eroded volcanic field (71 Gulch, Idaho, USA). These experiments are the first of their kind and provide valuable constraints on the flow of magma into sediments and will help better interpret natural deposits of past volcanic eruptions and provide inputs for models of future activity. This project will involve the training of undergraduate and graduate students with results and facilities shared with the scientific community. At the same time, the novel nature of the experiments will provide ample opportunities to engage public interest in science and volcanoes through videos and public facing blogs. The behavior of magma in the near surface directly influences the potential for eruptions and their resulting eruptive styles. To reach the surface, magma commonly must travel through unconsolidated sediments. This interaction influences the transport of magma, the stability of volcanic piles, and the potential for phreatomagmatic explosions. Meter-scale experiments of basaltic melt-sediment interactions will be integrated with computational simulations and field work to bridge the scale from experimental results and small natural deposits to a wider range of natural scenarios. The scale of the proposed experiments (mm to m) is large enough to overlap with natural systems (mm to 10’s of m). The experimental products, created using an automated plunger-driven magma extrusion device, will be both modeled numerically and compared with similar-sized natural magma-sediment deposits at the 71 Gulch Volcano, Idaho, USA. This field area contains deposits at both the experimental scale and larger, making it an ideal natural laboratory to investigate the scaling behavior of magma sediment interactions. The experimental and numerical results will be used to determine how long magma is available for mechanical mixing and thermal interactions, contributing to an understanding of how eruptions progress, and what conditions are necessary for explosive magma-sediment interactions. Specifically, the project will test two hypotheses: 1) The flow rate and temperature of the intruding magma is more important than the sedimentary host conditions in determining whether basaltic magma will pass through, mingle with, or be arrested by an unconsolidated sedimentary host at near surface conditions. 2) The textures and geometries of natural deposits of mingled basaltic magma and unconsolidated sediments can be used to estimate the flux rate and time scale at the time of formation. Experimental and numerical results will enable detailed quantitative interpretations of the forces and thermal history recorded in natural deposits in ways not previously possible.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.

该项目介绍了岩浆的相互作用以及它上升的材料以喂养小体积火山（地球上最丰富的火山地面）。当岩浆相互作用涉及含有可变量的水或冰的松散的沉积物时，岩浆可能以多种方式行为 - 穿过材料，造成爆炸，甚至在到达表面之前停止。这些不同的行为会影响火山的爆发方式，该项目将增强预测未来爆发的行为的能力，这对于挽救生命和保护基础设施至关重要。该项目涉及将30升（8加仑）的玄武岩融化为不同类型的松散沉积物 - 干燥，潮湿和冷冻的实验。这些实验为表征岩浆和沉积物相互作用的条件提供了机会，从而导致这些不同的行为。通过计算机模拟将扩大受物理实验限制的条件的表征，并与侵蚀火山场的天然产物进行比较（71 Gulch，美国爱达荷州，美国）。这些实验是同类的第一个实验，并对岩浆流入沉积物的流量提供了宝贵的限制，将有助于更好地解释过去火山喷发的自然沉积物，并为未来活动的模型提供投入。该项目将涉及对本科和研究生的培训，并与科学界共享结果和设施。同时，实验的新颖性将提供充足的机会，通过视频和公共面向博客吸引公众对科学和火山的兴趣。岩浆在近表面的行为直接影响喷发的潜力及其产生的喷发样式。为了到达地面，岩浆通常必须穿过未固结的沉积物。这种相互作用会影响岩浆的运输，火山桩的稳定性以及phreatomagmagications爆炸的潜力。玄武岩融化相互作用的仪表尺度实验将与计算模拟和现场工作集成，以弥合规模从实验结果和小型自然沉积到各种自然场景。所提出的实验（mm至m）的规模足够大，足以与天然系统重叠（MM至10的M）。使用自动柱塞驱动的岩浆扩展装置创建的实验产品将与美国爱达荷州71 Gulch火山的相似大小的天然岩浆沉积物进行单独建模。该野外区域在实验尺度和较大范围内都包含沉积物，这使其成为研究岩浆相互作用的缩放行为的理想天然实验室。实验和数值结果将用于确定岩浆可用于机械混合和热相互作用的时间，这有助于了解喷发的进展以及爆炸性岩浆 - 沉积物相互作用所需的条件。具体而言，该项目将检验两个假设：1）在确定玄武岩岩浆是否会通过，与未固定的沉积物在近表面条件下通过，混合或捕获的浸润岩浆的流速和温度比沉积宿主条件更为重要。 2）在形成时，可用于估计磁通量和未固结的沉积物的天然沉积物的质地和几何形状可用于估计通量速率和时间尺度。实验和数值结果将使自然沉积物中记录的力和热历史的详细定量解释以前是不可能的。该奖项反映了NSF的法定任务，并通过评估基金会的智力优点和更广泛的影响来审查标准。