Rheology for near real time forecasting of lava flows

用于熔岩流近实时预测的流变学

• 批准号: 2223098
• 负责人: Stephan Kolzenburg
• 金额: $ 41.06万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2223098&HistoricalAwards=false
• 关键词: Rheology; near; real; time; forecasting

Effective civil protection during effusive volcanic eruptions relies on accurate assessment of three main questions: 1. Where is the eruptive vent? 2. What areas will the lava flows affect? and 3. How fast will lava reach certain areas? Forecasting methods for lava flow paths and velocities require a detailed understanding of the lava’s flow properties (i.e. how viscous it is), the slope of the ground that the lava is flowing on and how much lava is erupted over a certain time interval. As lava flows down a volcano, it cools, crystallizes, and forms and/or loses bubbles, all of which affect how fast and how far lava may flow. An incomplete understanding of how the lava’s flow properties change makes accurate lava flow forecasting, and with that, hazard mitigation ahead of effusive eruptions, civil protection, and management of ongoing eruptive events, difficult. This project is motivated by 1) an incomplete understanding of lava flow properties, 2) a lack of integration of accurate flow properties in lava flow models and 3) the need for shorter response times between eruption onset and availability of lava flow-path forecasts. The project will tackle these challenges using the two most hazardous effusive volcanoes in the world, Nyiragongo and Nyamulagira as type localities. As an example, the 2021 eruption of Nyiragongo claimed over 30 lives, left 20,000 homeless, destroyed 3,500 houses, 12 schools, and 3 hospitals – a powerful expression of the impact lava flows can have on human lives. The core objectives are to 1) reconstruct the lava’s flow properties from natural samples 2) measure the lava’s viscosity at conditions relevant to its emplacement, and 3) integrate these data into a framework of satellite informed lava forecasting models. This may enable the development of a satellite-data-driven near-real time protocol for rapid and accurate forecasting of lava flow paths, which can then be applied during effusive eruptions to help guide decision making in civil protection efforts. Project results will also be incorporated into the SUNY Buffalo EarthEd program, providing content for K12 educators serving underrepresented communities, promoting science literacy. The project will support a graduate student at SUNY Buffalo and involves international collaborations (USA, Italy, France, DR Congo) in academia, development aid, and at volcano observatories.Lava rheology varies as a function of temperature, melt composition, crystal, and bubble content as well as strain rate. From eruption to flow cessation, basaltic lavas traverse a range of up to 10 orders of magnitude in their effective viscosity. The resulting non-linear changes in the lava’s transport behaviour determine how it accommodates deformation during emplacement and how fast and how far a lava can flow. The core objectives are to 1) reconstruct the lava’s rheology from natural samples 2) map the lava’s rheology over conditions relevant to their emplacement, and 3) integrate these data into a framework of satellite informed lava emplacement models. Using careful experimental characterization of the lava enables adaptation of a satellite-data-driven near-real time protocol to develop a tool for rapid and accurate forecasting of lava flow emplacement paths. The project will integrate field measurements, textural analysis, and targeted high temperature rheology experiments to generate the first complete rheological flow law for a basaltic lava that is derived from measurements at conditions relevant to lava emplacement and validated with field constraints. Using this flow law, the project will optimize a lava flow emplacement model, and integrate it into an existing near real time satellite monitoring system. This will create a highly adaptable tool for predicting lava flow paths and advance rates that is rooted in and optimized for the core physical property – lava rheology. The project sets out to: 1) Perform detailed petrographic analyses of natural samples and collect and evaluate field data of lava flow geometries 2) Use these in concert with viscosity measurements in controlled atmospheres to reconstruct the lava’s rheology during emplacement. This includes generating critical new data at reduced conditions, which are extremely scarce. 3) Employ the derived data to initialize and calibrate a deterministic lava flow model. This tool may enable near real time lava emplacement forecasting during future eruptions as well as forensic investigations of previous eruptions. The selected type localities enable testing both cooling- and volume-limited lava emplacement scenarios.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.

火山喷发期间有效的民防依赖于对三个主要问题的准确评估：喷发口在哪里？2. 熔岩流会影响哪些地区？和3。熔岩到达特定区域的速度有多快？预测熔岩流动路径和速度的方法需要详细了解熔岩的流动特性（即它的粘性），熔岩流动的地面坡度以及在一定时间间隔内喷发的熔岩量。当熔岩从火山流下来时，它会冷却、结晶、形成和/或失去气泡，所有这些都会影响熔岩流动的速度和距离。对熔岩流动特性如何变化的不完全理解，使得准确的熔岩流动预测变得困难，因此，在喷涌喷发之前减轻危险、公民保护和管理正在进行的喷发事件变得困难。这个项目的动机是：(1)对熔岩流特性的不完全理解；(2)在熔岩流模型中缺乏精确的流动特性的整合；(3)需要在喷发开始和可用的熔岩流路径预测之间缩短响应时间。该项目将利用世界上最危险的两座火山——尼拉贡戈火山和尼亚穆拉吉拉火山——来应对这些挑战。例如，2021年尼拉贡戈火山爆发造成30多人死亡，2万人无家可归，3500所房屋被毁，12所学校和3所医院被毁，这有力地表明了熔岩流对人类生命的影响。核心目标是：1)从自然样本中重建熔岩的流动特性；2)测量熔岩在与其就位相关的条件下的粘度；3)将这些数据整合到卫星信息熔岩预测模型框架中。这可能有助于开发一种由卫星数据驱动的近实时协议，以便快速准确地预测熔岩流动路径，然后在喷涌喷发期间应用该协议，以帮助指导民防工作的决策。项目成果也将纳入纽约州立大学布法罗分校接地项目，为K12教育工作者提供内容，服务于代表性不足的社区，促进科学素养。该项目将支持纽约州立大学布法罗分校的一名研究生，并涉及学术界、发展援助和火山观测站的国际合作（美国、意大利、法国、刚果民主共和国）。熔岩流变性随温度、熔体成分、晶体、气泡含量以及应变速率而变化。从喷发到流动停止，玄武岩熔岩的有效粘度可达10个数量级。由此产生的熔岩传输行为的非线性变化决定了它在就位过程中如何适应变形，以及熔岩流动的速度和距离。核心目标是：1)从自然样本中重建熔岩的流变性；2)在与其就位相关的条件下绘制熔岩的流变性图；3)将这些数据整合到卫星信息熔岩就位模型框架中。通过对熔岩进行仔细的实验表征，可以采用卫星数据驱动的近实时协议，开发一种快速准确预测熔岩流就位路径的工具。该项目将整合现场测量、结构分析和有针对性的高温流变实验，生成第一个完整的玄武岩熔岩流变流动规律，该规律来自于与熔岩就位相关的条件下的测量，并在现场约束条件下进行验证。利用这一流动规律，该项目将优化熔岩流就位模型，并将其整合到现有的近实时卫星监测系统中。这将创建一个高度适应性的工具，用于预测熔岩流动路径和推进速度，该工具植根于并优化了岩心的物理性质-熔岩流变性。该项目旨在：1)对自然样品进行详细的岩石学分析，收集和评估熔岩流几何形状的现场数据；2)将这些数据与受控气氛下的粘度测量相结合，重建熔岩在就位期间的流变学。这包括在极其稀缺的简化条件下生成关键的新数据。3)利用导出的数据初始化和校准确定性熔岩流模型。这个工具可以在未来火山喷发期间进行近乎实时的熔岩就位预测，也可以对以前的火山喷发进行法医调查。选定的类型地点能够测试冷却和体积有限的熔岩放置方案。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。