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

该项目涉及岩浆和物质的相互作用，通过这些物质上升到小体积火山（地球上最丰富的火山地貌）。 当岩浆相互作用涉及含有不同量的水或冰的松散沉积物时，岩浆可能会以各种方式表现出来-穿过材料，引起爆炸，甚至在到达表面之前停止。这些不同的行为会影响火山如何喷发，该项目将提高预测未来喷发行为的能力，这对拯救生命和保护基础设施至关重要。该项目包括将30升（8加仑）玄武岩熔体注入不同类型的松散沉积物-干燥，潮湿和冷冻。这些实验提供了机会，以描述导致这些不同行为的岩浆和沉积物相互作用的条件。条件的表征，这是有限的物理实验，将扩大使用计算机模拟和与自然产品的侵蚀火山领域（71峡谷，爱达荷州，美国）的比较。这些实验是此类实验中的第一次，为岩浆流入沉积物提供了有价值的限制，将有助于更好地解释过去火山爆发的自然沉积物，并为未来活动的模型提供投入。该项目将培训本科生和研究生，并与科学界分享成果和设施。与此同时，实验的新颖性将提供充足的机会，通过视频和面向公众的博客吸引公众对科学和火山的兴趣。岩浆在近地表的行为直接影响喷发的可能性和喷发方式。为了到达地表，岩浆通常必须穿过未固结的沉积物。这种相互作用影响着岩浆的输送、火山岩堆的稳定性以及蒸汽岩浆爆炸的可能性。玄武岩熔体-沉积物相互作用的米级实验将与计算机模拟和实地工作相结合，以将实验结果和小型自然沉积物的规模与更广泛的自然情景联系起来。拟议实验的规模（毫米到米）大到足以与自然系统（毫米到10米）重叠。实验产品，使用自动柱塞驱动的岩浆挤出装置，将同时模拟数字和类似大小的天然岩浆沉积物矿床在71峡谷火山，爱达荷州，美国进行比较。这个领域包含在实验规模和更大的存款，使其成为一个理想的天然实验室，研究岩浆沉积物相互作用的标度行为。实验和数值计算结果将用于确定岩浆多久可用于机械混合和热相互作用，有助于了解火山爆发的进展，以及爆炸性岩浆-沉积物相互作用所需的条件。具体而言，该项目将测试两个假设：1）侵入岩浆的流速和温度比沉积宿主条件更重要，以确定玄武岩浆是否会通过，混合或被近地表条件下的未固结沉积宿主所阻止。2)玄武岩浆与松散沉积物混合形成的天然矿床的结构和几何形状可用于估计形成时的流量和时间尺度。实验和数值结果将使详细的定量解释的力量和热历史记录在自然deposits.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

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.