Rheology for near real time forecasting of lava flows

有效的火山喷发期间的平民保护依赖于三个主要问题的准确评估：1。火山口在哪里？2.熔岩流会影响哪些地区？和3.熔岩到达某些地区的速度有多快？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有多少熔岩喷发。当熔岩从火山流下时，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预测变得困难，因此，在喷发之前减轻灾害，民事保护和正在进行的喷发事件的管理变得困难。该项目的动机是：1）对熔岩流特性的不完全理解，2）缺乏熔岩流模型中准确流动特性的集成，3）需要缩短喷发开始和熔岩流动路径预测之间的响应时间。该项目将利用世界上最危险的两座喷发火山尼拉贡戈火山和尼亚穆拉吉拉火山作为典型地点来应对这些挑战。例如，2021年的尼拉贡戈火山爆发夺走了30多人的生命，造成2万人无家可归，摧毁了3,500所房屋，12所学校和3所医院-这是熔岩流对人类生活影响的有力表达。核心目标是：1）从天然样品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通知熔岩预测模型的框架中。这可能有助于开发一种卫星数据驱动的近实时协议，用于快速准确地预测熔岩流路径，然后可在喷发期间应用该协议，以帮助指导民事保护工作的决策。项目成果还将纳入纽约州立大学布法罗地球教育计划，为服务于代表性不足的社区的K12教育工作者提供内容，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）。熔岩流变学随温度、熔体成分、晶体和气泡含量以及应变率的函数而变化。从喷发到流动停止，玄武质熔岩的有效粘度可达10个数量级。由此产生的熔岩运输行为的非线性变化决定了它在就位期间如何适应变形以及熔岩可以流动的速度和距离。其核心目标是：1）从天然样品中重建熔岩的流变学; 2）绘制熔岩在与其就位相关的条件下的流变学; 3）将这些数据整合到卫星通知熔岩就位模型的框架中。使用仔细的实验表征的熔岩，使适应卫星数据驱动的近实时协议，开发一种工具，快速准确地预测熔岩流侵位路径。该项目将整合现场测量，纹理分析和有针对性的高温流变实验，以生成第一个完整的玄武熔岩流变流动定律，该定律来自于与熔岩就位相关的条件下的测量，并通过现场约束进行验证。利用这一流动定律，该项目将优化熔岩流侵位模型，并将其纳入现有的近真实的时间卫星监测系统。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率，该工具植根于核心物理特性-熔岩流变学并针对其进行优化。该项目旨在：1）对天然样本进行详细的岩相分析，并收集和评估熔岩流几何形状的现场数据2）使用这些数据与受控大气中的粘度测量相结合，以重建熔岩就位期间的流变学。这包括在极其稀缺的简化条件下生成关键的新数据。3)使用导出的数据初始化和校准确定性熔岩流模型。这种工具可以使近真实的时间熔岩侵位预测在未来的喷发以及法医调查以前的喷发。该奖项反映了NSF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。

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.