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

这个项目涉及岩浆和物质的相互作用，岩浆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到含有不同数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——穿过物质，引起爆炸，甚至在到达表面之前就停止了。这些不同的行为会影响火山喷发的方式，该项目将提高预测未来火山喷发行为的能力，这对拯救生命和保护基础设施至关重要。这个项目包括将30升（8加仑）玄武岩熔体注入不同类型的松散沉积物——干的、湿的和冷冻的。这些实验为描述岩浆和沉积物相互作用的条件提供了机会，这些条件导致了这些不同的行为。将利用计算机模拟和与来自侵蚀火山场的天然产物进行比较（71 Gulch，爱达荷州，美国），扩大受物理实验限制的条件特征。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约束，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输入。该项目将包括对本科生和研究生的培训，其成果和设备将与科学界共享。与此同时，这些实验的新颖性将为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提供充足的机会。近地表岩浆的活动直接影响火山喷发的可能性及其形成的喷发样式。岩浆要到达地表，通常必须穿过松散的沉积物。这种相互作用影响了岩浆的输送、火山桩的稳定性和火山喷发的可能性。玄武岩熔体-沉积物相互作用的米尺度实验将与计算模拟和实地工作相结合，以架起从实验结果和小型自然沉积物到更广泛的自然情景的桥梁。所提出的实验的尺度（毫米到米）足够大，与自然系统（毫米到十分之一米）重叠。这些实验产品是由一种自动柱塞驱动的岩浆挤压装置产生的，它们将被进行数值模拟，并与美国爱达荷州Gulch火山71号类似大小的天然岩浆沉积物进行比较。该地区既有实验规模的矿床，也有较大规模的矿床，是研究岩浆-沉积物相互作用结垢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，有助于了解火山喷发如何进行，以及爆炸性岩浆-沉积物相互作用所需的条件。具体来说，该项目将测试两个假设：1)在决定玄武岩岩浆是否会在近地表条件下穿过、混合或被未固结的沉积宿主阻止时，侵入岩浆的流速和温度比沉积宿主条件更重要。2)玄武质岩浆与松散沉积物混合形成的天然沉积物的结构和几何形状可用于估算形成时的通量速率和时间尺度。实验和数值结果将能够以以前不可能的方式详细定量地解释自然沉积物中记录的力和热历史。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。

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.