Physical Properties of Bubble- and Crystal-Bearing Melts and their Implications for Eruption Dynamics: Theoretical, Experimental and Field-Based Studies

在火山内部，气泡的形成（水泡），岩浆破碎成离散的碎片（碎裂），以及上升的岩浆气泡中的气体损失（脱气）是控制岩浆喷发动力学的关键过程。本项目的最终目标是了解这些过程如何相互作用并反映在火山喷发及其产生的产物的特征中，建议对喷发动力学和喷发产物建模进行实验和数值研究，以了解是什么控制着火山喷发是爆发性还是喷发性。研究任务将包括测量黑曜石中的挥发物含量和梯度，从爆炸和喷出，以确定泡状，脱气和破碎的时间尺度。此外，该团队将开发管道模型，以了解流动，脱气和岩浆流变学变化的竞争和相互作用的影响。计划继续对气泡和晶体的影响或悬浮液的流变学进行实验研究，以便在管道流动模拟中纳入更好的流变学模型。该项目为三名学生提供研究生培训，支持国际合作，并与高级光源的新用户设施进行互动。由于该项目的目的是了解火山爆发的控制方式和管道过程和喷发物质的特征（质地，挥发性含量）之间的关系，结果将提供一个更好的基础，从建模的角度来估计火山灾害，并从测量历史和史前存款。

Inside volcanoes, the formation of bubbles (vesiculation), the breaking of magma into discrete pieces (fragmentation), and the loss of gas in bubbles from ascending magma (degassing) are the key processes that control the dynamics of the erupting magma. The ultimate goal of this project is to understand how these processes interact and are reflected in the features of a volcanic eruption and the products it produces.It is proposed to perform experimental and numerical studies of eruption dynamics and modeling of eruption products in order to understand what controls whether an eruption will be explosive or effusive. The research tasks will include measurements of volatile contents and gradients in obsidian from both explosive and effusive eruption to determine the timescales for vesiculation, degassing and fragmentation. In addition, the team will develop conduit models to understand the competing and interacting effects of flow, degassing, and changes in magma rheology. It is planned to continue experimental studies of the effects of bubbles and crystals or the rheology of suspensions to allow for better models of rheology to be included in conduit flow simulations.This project provides graduate training for three students, supports international collaboration, and interaction with a new user facility at the Advanced Light Source. Because the project is aimed at understanding the controls on eruption style and the relationship between conduit processes and features of erupted materials (texture, volatile content), results will provide a better basis for estimating volcanic hazard, both from a modeling perspective, and from measurements on historic and prehistoric deposits.