Collaborative Research: Linking pyroclastic surge dynamics and deposits through integration of field data, multiphase numerical modeling, and experiments

合作研究：通过现场数据、多相数值模拟和实验的整合，将火山碎屑涌动动力学与沉积物联系起来

• 批准号: 2034788
• 负责人: Amanda Clarke
• 金额: $ 27.4万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-15 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2034788&HistoricalAwards=false
• 关键词: Collaborative; Research; Linking; pyroclastic; surge

Explosive volcanic eruptions unleash flows of hot gases and particles called pyroclastic surges; these are deadly to humans and severely damage or destroy buildings and other infrastructure. Within the United States, pyroclastic surges are a potential hazard in many areas such as the Southwest and along the Cascade Range of the Pacific Northwest. Understanding parameters such as speed, pressure, temperature, and particle concentration is necessary to predict pyroclastic surge hazards and to take mitigative measures. Measurements of active pyroclastic surges are essentially impossible because of their unpredictability and the extreme conditions they create. As a result, we must use indirect methods: (1) detailed study of the deposits that were produced by pyroclastic surges, which can be studied after a volcano has gone quiet; (2) experiments aimed at replicating some aspects of the surges; and (3) computer modeling of the flows. This project uses these three methods iteratively. The work will provide new insights and tools to use in forecasting and mitigating volcanic hazards. In addition, the work will be done by a diverse, newly-formed multi-university team, will train two new Ph.D. students, and will strengthen partnership between academic researchers with the U.S. Geological Survey, which has primary responsibility for hazard assessment.Controls on the development of local facies in pyroclastic surge deposits as well as larger-scale parameters such as proximal-to-distal facies variations, runout, and damage potential are poorly understood. We will address the following research questions: (1) At the local scale (e.g., individual outcrop or group of outcrops), what are the relationships of bed forms and facies to sedimentation from suspended load, bed load flux, and local topography? (2) At the large scale (proximal to distal), what are the roles of sedimentation, topography, initial temperature, mass flux, and atmospheric entrainment on large-scale facies distribution, runout distance, and damage potential? The proposed work includes three components. (1) Detailed field studies will focus on two well-preserved, young deposits (Ubehebe volcano, California; Crater Elegante, Sonora), with documentation of facies, grainsize, and componentry as functions of distance from vent and local topographic setting. (2) Experiments will test and extend a simple relationship between dune-form parameters measurable in the field, bed load flux, and suspended load sedimentation flux. (3) Multiphase numerical modeling will use adaptive mesh refinement to resolve fluxes near the bed, will improve the numerical solution of coupling between gas and very fine ash (key for surge transport and deposition), and will use unstructured mesh technology to model surge transport over complex natural terrains. A new multiphase modeling tool that results from the project will be available for the research community at large.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.

爆炸性火山喷发释放了热气和颗粒的流动，称为火山碎屑潮流；这些对人类是致命的，严重破坏了建筑物和其他基础设施。 在美国，在许多地区，例如西南和太平洋西北的喀斯喀特山脉，火山碎屑的潮流都是一种潜在的危害。了解速度，压力，温度和颗粒浓度等参数对于预测火山碎屑的危害并采取缓解措施是必要的。由于它们的不可预测性及其创造的极端条件，因此基本上不可能测量活跃的火山碎屑潮流。 结果，我们必须使用间接方法：（1）详细研究由火山碎屑涌动产生的沉积物，这可以在火山安静后进行研究； （2）旨在复制潮流的某些方面的实验； （3）流的计算机建模。 该项目使用这三种方法迭代。这项工作将为预测和减轻火山危害提供新的见解和工具。 此外，这项工作将由多样化的新成立的多元大学团队完成，将培训两个新的博士学位。学生，并将加强学术研究人员与美国地质调查局之间的伙伴关系，该调查对危害评估负有主要责任。控制着危害的危险评估，以开发火山碎屑涌现的当地相以及较大规模的参数，例如近端到距离的相位相位的差异，rumiations差异，跳动和损害潜力较差。 我们将解决以下研究问题：（1）在本地规模（例如，单个露头或露头组），床形式和相的关系与悬挂式负载，床负荷通量和当地地形的沉积之间的关系是什么？ （2）在大规模的大规模上（近端到远端），沉积，地形，初始温度，质量通量和大气夹带在大型相分布，跳动距离和损害潜力上的作用是什么？拟议的工作包括三个组成部分。 （1）详细的现场研究将集中于两个保存完好的年轻沉积物（加利福尼亚州的Ubehebe火山； Sonora火山口优雅），并记录了相，晶体化和组件作为距离通风口和本地地形环境的距离的功能。 （2）实验将测试并扩展可在田间可测量的沙丘形式参数，床负荷通量和悬浮负载沉积通量之间的简单关系。 （3）多相数字建模将使用自适应网状精炼来解决床附近的通量，将改善气体和非常细的灰分之间耦合的数值解决方案（对于激增和沉积的关键），并将使用非结构化的网格技术来模拟复杂自然领域的潮流运输。 该项目将为整个研究社区提供一种新的多相建模工具，该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响标准，认为值得通过评估来获得支持。