Collaborative Research: The Movement of Gas & Crystals Beneath Kilauea

这是芝加哥大学的Alfred Anderson和俄亥俄州立大学的Dork Sahagian的合作项目。该项目的主要目标是确定基拉韦厄山顶下是否有天然气积聚。这个想法是，在构造顶端的气体积聚可以导致顶峰喷口的持续局部化。其他目标是：1)利用熔融包裹体确定基拉韦厄火山下橄榄石结晶的深度；2)确认基拉韦厄火山母岩浆中二氧化碳和水的初始体积浓度。将研究基拉韦厄陆基拉韦厄玄武岩。用电子探针分析橄榄石斑晶中玻璃夹杂物的主要元素和S，用红外光谱分析H20和co2。此外，还测量了玻璃状海底玄武岩中囊泡的大小、丰度和气压。将测量玻璃内含物中气泡的大小和气体压力，以便与主玻璃中的囊泡进行比较。将进行计算，以评估基拉韦厄岩浆演化体中气泡的聚集和上升速度。这些结果将与现有的关于排气、岩浆流入和喷发的历史速率的数据进行比较。这些数据和计算将用于测试和完善基拉韦厄火山喷发和演化的现有模型。总的来说，pi将测试基拉韦厄火山是一个集中火山的想法，因为上升的气体寻求并保持在其顶部的一个出口。

This is a collaborative project between Alfred Anderson of the University of Chicago and Dork Sahagian of Ohio State.The main goal of the project is to establish whether gas accumulates beneath Kilauea's summit. The idea is that gas accumulation at the structural apex can cause persistent localization of a summit vent. Additional goals are: 1) to use melt inclusions to establish the depths of olivine crystallization beneath Kilauea: and 2) to confirm the initial bulk concentration of C02 and H20 in Kilauean parent magma. Subaerial and submarine Kilauean basalts will be studied. Inclusions of glass in Olivine phenocrysts will be analyzed for major elements and S by electron microprobe and for H20 and C02 by infra-red spectroscopy. In addition the size, abundance and gas pressure of vesicles in glassy submarine basalts will be measured. The sizes and gas pressures of gas bubbles in glass inclusions will be measured for comparison with the vesicles in host glasses. Calculations will be performed to assess the coalescence and rate of rise of bubbles in the evolving body of magma beneath Kilauea. The results will be compared with existing data on the historical rates of outgassing, magma influx, and eruption. The data and computations will be used to test and refine existing models of the outgassing and evolution of Kilauea volcano. Overall, the PIs will test the idea that Kilauea is a centralized volcano because rising gas seeks and maintain a vent at its summit.