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事保护有赖于对三个主要问题的准确评估：1.喷发喷口在哪里？2.熔岩流将影响哪些地区？3.熔岩到达某些地区的速度有多快？熔岩流动路径和速度的预测方法需要详细了解熔岩的流动特性(即熔岩的粘性)、熔岩在其上流动的地面坡度以及在特定时间间隔内喷发的熔岩数量。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可能流动的速度和距离。对熔岩流动性质如何变化的不完全理解使得准确的熔岩流动预测，以及由此而来的在喷发之前的灾害缓解、民事保护和持续喷发事件的管理变得困难。该项目的动机是1)对熔岩流动特性的了解不全面，2)熔岩流动模型中缺乏准确的流动特性，3)喷发开始和熔岩流动路径预报之间需要更短的响应时间。该项目将利用世界上两座最危险的喷发火山尼拉贡戈和尼亚穆拉吉拉作为典型的地点来应对这些挑战。例如，2021年尼拉贡戈火山喷发夺走了30多人的生命，导致2万人无家可归，摧毁了3500所房屋、12所学校和3所医院--有力地表明了熔岩流可能对人类生活产生的影响。核心目标是1)从自然样品中重建熔岩的流动特性，2)测量熔岩在与其侵位有关的条件下的粘度，以及3)将这些数据整合到卫星信息的熔岩预测模型框架中。这可能有助于开发一种卫星数据驱动的近乎实时的协议，用于快速准确地预测熔岩流动路径，然后可在喷发期间加以应用，以帮助指导民事保护工作中的决策。项目成果还将纳入纽约州立大学布法罗大地计划，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、法国和刚果民主共和国)。熔岩的流变性随着温度、熔体成分、晶体和气泡含量以及应变率的变化而变化。从喷发到停止流动，玄武岩熔岩的有效粘度范围可达10个数量级。由此产生的熔岩运移行为的非线性变化决定了它在侵位过程中如何适应变形，以及熔岩可以流动的速度和距离。核心目标是1)从自然样品重建熔岩的流变学，2)绘制熔岩的流变学与其侵位相关的条件图，以及3)将这些数据整合到卫星信息的熔岩侵位模型的框架中。利用熔岩的仔细实验特征，能够适应卫星数据驱动的近实时协议，以开发一种工具，用于快速和准确地预测熔岩流侵位路径。该项目将整合现场测量、结构分析和有针对性的高温流变学实验，以生成第一个完整的玄武岩熔岩流变定律，该定律是根据与熔岩侵位相关的条件下的测量得出的，并通过现场约束进行验证。利用这一流动规律，该项目将优化熔岩流定位模型，并将其整合到现有的近实时卫星监测系统中。这将创建一种高度适应性的工具，用于预测熔岩流动路径和推进速度，该工具植根于核心物理性质-熔岩流变学，并针对其进行了优化。该项目计划：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)将这些数据与受控大气中的粘度测量结合使用，以重建侵位期间熔岩的流变学。这包括在极其稀缺的条件下生成关键的新数据。3)利用得到的数据对确定性熔岩流模型进行了初始化和标定。这一工具可以在未来喷发期间实现近乎实时的熔岩侵位预测，以及对以前喷发的法医调查。选定的类型地点可以测试冷却和容量有限的熔岩就位场景。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。