Linking geodetic observations with gas emissions to characterize magmatic activity at a subduction zone volcano: Mt. Baker (Washington)

将大地测量观测与气体排放联系起来，以表征俯冲带火山的岩浆活动：贝克山（华盛顿）

• 批准号: 0538317
• 负责人: Juliet Crider
• 金额: $ 10.7万
• 依托单位: Western Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0538317&HistoricalAwards=false
• 关键词: Linking; geodetic; observations; gas; emissions

Research at erupting volcanoes has shown that high surface temperatures, gas emissions, and geodetic and seismic unrest are signatures of magmatic activity at depth. Few studies have correlated such geophysical and geochemical measurements at non-erupting volcanoes. This project is a 2-year pilot study to investigate the relationship between volcano degassing and magmatic activity by collecting gas samples and geodetic measurements at Mount Baker volcano, Washington. The volcano has shown no signs of historical seismic unrest, yet actively emits both carbon dioxide and hydrogen sulfide at rates similar to other volcanoes where intrusions have been inferred from seismicity. Mount Baker is of additional interest because of an unexplained increase in gas emissions and thermal activity that occurred in 1975. The goals of this study are to gather sufficient data to discern whether the investigators will be able to characterize the patterns of gravity change and surface deformation at a quiescent, degassing, subduction zone volcano, and evaluate the relationship between gas emission and geodetic changes over time. The researchers will reoccupy USGS electronic distance meter (EDM) sites, last surveyed in 1983, with GPS and also conduct microgravity studies. The principle investigator will collaborate with US Geological Survey colleagues to collect repeat airborne gas flux measurements over the volcano and collect fumarole gas samples and measure temperatures on the ground. Gas will be analyzed for composition and helium isotope ratios. When these datasets are considered together with geodetic observations, much can be learned about the magmatic system at Mount Baker and other volcanoes by analogy.The integration of GPS and gravity measurements with gas geochemistry has the potential to revolutionize our understanding of volcanic processes. However, few previous studies have attempted to correlate thermal and gas emissions with geodetic data at quiescent volcanoes; therefore, therefore this research may have a significant benefit to the understanding of volcanic processes and, potentially, hazards. Further, the results may be used to infer the mechanisms that caused the gas/thermal unrest at Mount Baker in 1975. Mt. Baker represents the most significant volcanic hazard to northwest Washington and the lower mainland of British Columbia, home to more than 2.5 million people. Long-term societal benefits may include enhanced ability to predict the character of future volcanic activity.

对火山爆发的研究表明，高表面温度、气体排放、大地和地震动荡是深部岩浆活动的标志。很少有研究将非喷发火山的地球物理和地球化学测量结果联系起来。本项目是一项为期2年的试点研究，通过在华盛顿贝克山火山收集气体样品和大地测量，调查火山脱气和岩浆活动之间的关系。这座火山没有显示出历史上地震动荡的迹象，但活跃地排放二氧化碳和硫化氢，其速率与其他火山相似，这些火山的入侵是从地震活动中推断出来的。由于1975年发生的气体排放和热活动不明原因的增加，贝克山引起了额外的兴趣。本研究的目标是收集足够的数据，以辨别研究人员是否能够描述静态，脱气，俯冲带火山的重力变化和表面变形模式，并评估气体排放和大地测量变化之间的关系。研究人员将重新使用美国地质勘探局的电子测距仪（EDM）站点，最后一次测量是在1983年，使用GPS并进行微重力研究。主要研究人员将与美国地质调查局的同事合作，收集火山上空重复的空中气体通量测量结果，并收集火山口气体样本和测量地面温度。将分析气体的成分和氦同位素比率。当这些数据集被认为是与大地测量观测一起，可以学到很多关于贝克山和其他volcanoes.The全球定位系统和重力测量与气体地球化学相结合的岩浆系统有可能彻底改变我们的火山过程的理解。然而，很少有以前的研究试图在静止的火山与大地测量数据的热量和气体排放量，因此，因此，这项研究可能有一个显着的好处，了解火山过程，并可能，危害。此外，这些结果可用于推断1975年贝克山气体/热动荡的机制。山贝克火山是华盛顿西北部和不列颠哥伦比亚省内陆地区最严重的火山灾害，该省拥有250多万人口。长期的社会效益可能包括提高预测未来火山活动特征的能力。