Magmatic Degassing: Experimental and Textural Constraints

加德纳火山爆发是由气泡的增长驱动的。 许多模型认为，岩浆要么是爆炸性喷发，要么是作为熔岩喷出，这取决于岩浆有效脱气的能力，这是由熔体将气体转化为气泡控制的。 如果气泡和熔体失去平衡，超压就会发展并使岩浆破碎。 尽管气泡在火山活动中发挥着核心作用，但实验工作直到最近才开始解决它们在硅酸盐熔体中的生长问题。 该项目通过详细分析气泡生长速率和气泡与熔体之间的平衡（作为压降的函数），研究硅酸盐熔体中气泡生长的动力学。 受控的水热实验将被用来施加可变的减压历史的气体熔体系统，以研究气泡如何生长，并在什么速度的压力下降做气泡熔体不能保持平衡。 这些数据对于理解喷发动力学和开发更好的喷发管道流模型都至关重要。 实验将在阿拉斯加大学费尔班克斯的实验岩石学实验室进行，所有产品将在阿拉斯加大学费尔班克斯的先进仪器实验室进行分析。

Gardner EAR- 0087853Volcanic eruptions are driven by the growth of gas bubbles. Many models suggest that magmas either erupt explosively or effuse as lava, depending on the magma's ability to degas efficiently, which is controlled by the melt transferring gas to bubbles. If bubbles and melt fail fall out of equilibrium, over-pressure develops and fragments the magma. Despite the central role that gas bubbles play in volcanism, experimental work has only recently begun to address their growth in silicate melts. This project addresses the dynamics of bubble growth in silicate melts through detailed analysis of the rates of bubble growth and equilibrium between bubbles and melt as a function of pressure drop. Controlled hydrothermal experiments will be used to impose variable decompression histories on gas-melt systems in order to examine how bubbles grow and at what rates of pressure decrease do bubbles-melt fail to remain in equilibrium. These data are crucial inboth understanding of eruption dynamics and developing better modeling of conduit flow in eruptions. Experiments will be performed in the Experimental Petrology Laboratory at the University of Alaska Fairbanks, and all products will be analyzed in the Advanced Instrumentation Laboratory at the University of Alaska Fairbanks.