Particle Trajectories in Volcanic Plumes: Model Development and Testing at Inyo Craters, California, United States

这项研究的主要目标是开发一种火山羽流模型，跟踪羽流中岩石颗粒(火山碎屑或火山灰)的路径，并计算这些颗粒落在哪里。拟议的研究对社会的一个影响是使用该模型来预测潜在的火山喷口附近的部分，这是世界各地火山危险预测和危险潜在地图的重要组成部分。它还计划使用该模型生成新的图形计算曲线图，以根据特菲拉陨落数据估计喷发参数，如喷发柱高度和风速。加州因约陨石坑的实地部分研究将为未来潜在的喷发提供重要的制约因素，这些喷发可能会影响里诺和洛杉矶-拉斯维加斯之间快速增长的走廊的主要交通走廊和分水岭。其他更广泛的影响包括通过培训一名地质学和计算科学的女博士生，整合代表不足的群体和科学学科。调查人员已将问题分解为几个部分。这项研究将涉及的第一部分，是通过模拟大颗粒在喷发流场中的运动来模拟大型火山碎屑的近距离散落。一个大粒子模块(LPM)正在编写中，以便与动态火山羽流模拟ATAM(活动跟踪器高分辨率大气模型)一起工作，并可能被添加到该模型中。该模块将用于调查受静止和视频摄影约束的烟柱内的火山碎屑路径和分布，并根据地面火山碎屑分布的现场数据测试模型预测。对于研究的野外部分，建议使用差分GPS绘制和测量精心选择的喷发沉积物近端的沉积物厚度和粒度，以进行精确定位。他们将研究美国西南部最新的大型普林尼安式喷发矿床--因约特弗拉斯火山。现场数据将通过对地面碎屑岩的模型分布和实测分布进行统计比较来进行分析。模型的优劣将通过使用其对现场数据的收敛程度来表征，并将该收敛程度与使用过去模型的结果进行比较。据设想，拟议的研究将导致开发一个大颗粒模块，该模块与Atham一起工作，并可以合并到Atham中，开始产生第一个完整的、3-D Tephra沉积模拟。在适当的喷发条件下，模拟应产生与现场数据一致的火山碎屑在烟柱中的位置和浓度，以及地面上大型火山碎屑的分布，以及厚度、同质或粒度等值线。

The main goal of this research is the development of a model for volcanic plumes that tracks the paths of rocky particles (pyroclasts or tephra) within the plume and calculates where these particles fall. One impact of the proposed research for society is to use the model to forecast the proximal (near to the vent) portion of potential tephra fall maps, which are an important part of hazards forecasting and hazards potential mapping at volcanoes worldwide. It is also planned to use the model to generate new graphical calculation plots to estimate eruption parameters, such as eruption column height and windspeed, from tephra fall data. The field portion of the research at Inyo Craters, CA, will provide important constraints on potential future eruptions that could impact major transportation corridors and watersheds in the rapidly growing corridor between Reno and Los Angeles?Las Vegas. Additional broader impacts include the integration of underrepresented groups and scientific disciplines through the training of a female Ph.D. student in both Geology and Computational Sciences. The investigators have broken the problem into several parts. The first part, which will be addressed by this research, is to model the proximal fallout of large pyroclasts by simulating the motion of large particles in eruptive flow fields. A large-particle module (LPM) is being written to work with and potentially be added to ATHAM (Active Tracer High resolution Atmospheric Model), a dynamic volcanic plume simulation. The module will be used to investigate pyroclast paths and distributions within the plume as constrained by still and video photography, and to test model predictions against field data on pyroclast distribution on the ground. For the field portion of the research, it is proposed to map and measure deposit thickness and grainsize in the proximal region of carefully chosen eruption deposits using differential GPS for precise location. They will study the most recent, large Plinian-type eruption deposits in the southwestern U.S., the Inyo tephras. The field data will be analyzed by statistical comparison of the modeled and the measured distributions of clasts on the ground. The goodness of the model will be characterized by using the degree of its convergence to the field data, and comparing this degree of convergence to the results from using past models. It is envisaged that the proposed research will result in the development of a large particle module that works with and can be incorporated into ATHAM to begin to produce the first full, 3-D tephra deposition simulation. Given appropriate eruptive conditions, the simulation should produce visualizations of pyroclast position and concentration within the plume, as well as distributions of large pyroclasts on the ground, and thickness, isomass or grain size isopleths in good agreement with field data.