Virunga Volcanic SO2 Emissions Research (VISOR) Project

维龙加火山 SO2 排放研究 (VISOR) 项目

• 批准号: 0910795
• 负责人: Simon Carn
• 金额: $ 12.44万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-16 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0910795&HistoricalAwards=false
• 关键词: Virunga; Volcanic; SO2; Emissions; Research

Sulfur dioxide (SO2) emissions from non-arc volcanoes constitute a significant component of the global volcanic sulfur budget, and have been assumed to scale directly with erupted lava volume (i.e. that there is no excess sulfur). However, to date there have been very few efforts to prove this, particularly for alkaline volcanoes. This project will merge remote sensing and petrological analysis to investigate the origins and dynamics of SO2 emissions from Nyamuragira and Nyiragongo, the active, alkaline volcanoes in the Virunga region of the western arm of the East African Rift in DR Congo. Both Nyamuragira and Nyiragongo are prodigious sulfur emitters, the former during its frequent effusive eruptions and the latter via persistent passive degassing since 2002. To date there has been no concerted attempt to link these SO2 emissions with magma production, or to investigate the origin of the exceptional SO2 output. The main components of the VISOR project are: (1) Analysis of satellite data collected by several instruments since 1978 to develop a complete record of recent SO2 emissions from the Virunga volcanoes. An up-to-date map of recent lava flows will also be constructed; (2) Fieldwork in DR Congo to collaborate with Congolese scientists at the Goma Volcano Observatory (GVO) on ground-based SO2 monitoring at Nyiragongo, including measurement of SO2 emissions and interpretation of the data alongside other volcanological datasets collected by GVO and collaborators. Validation of satellite measurements will be achieved by comparing coincident field- and satellite-based SO2 measurements; (3) Petrological analyses of volatile concentrations and speciations in historical eruptive products of Nyamuragira and Nyiragongo to determine the extent of magma degassing during eruptions. These data will be combined with the remotely sensed SO2 measurements to assess the relationship between melt sulfur loss and measured SO2 production for a series of eruptive events; thus shedding new light on the incidence of excess sulfur emissions at non-arc, alkaline volcanoes, and into the behavior of sulfur and other volatiles in alkali-basaltic magmas. Broader impacts of this study include: strengthening of international collaborative links between groups in the USA, Africa, and Europe; training of a female graduate student in remote sensing, petrological techniques and fieldwork; a valuable infusion of expertise and collaborative activity for African scientists at GVO, which has suffered many years of neglect and civil unrest; outreach projects in Goma using satellite data acquired for the project; and the addition of exotic volcanic rock compositions to the National Rock Collection archive at the Smithsonian Institution, for future research efforts.

非弧火山的二氧化硫 (SO2) 排放构成了全球火山硫预算的重要组成部分，并被认为与喷发的熔岩量直接相关（即不存在多余的硫）。然而，迄今为止，很少有人努力证明这一点，特别是对于碱性火山。该项目将结合遥感和岩石学分析，研究尼亚穆拉吉拉和尼拉贡戈二氧化硫排放的来源和动态，尼亚穆拉吉拉和尼拉贡戈是刚果民主共和国东非大裂谷西臂维龙加地区的活碱性火山。尼亚穆拉吉拉火山和尼拉贡戈火山都是巨大的硫排放源，前者频繁喷发，后者自 2002 年以来持续被动脱气。迄今为止，尚未有人一致尝试将这些 SO2 排放与岩浆产生联系起来，或调查异常 SO2 排放的起源。 VISOR 项目的主要组成部分是： (1) 分析 1978 年以来由多种仪器收集的卫星数据，以形成维龙加火山近期二氧化硫排放的完整记录。还将绘制近期熔岩流的最新地图； (2) 在刚果民主共和国进行实地考察，与戈马火山观测站 (GVO) 的刚果科学家合作，在尼拉贡戈进行地面 SO2 监测，包括测量 SO2 排放量并对数据以及 GVO 和合作者收集的其他火山数据集进行解释。卫星测量结果的验证将通过比较同时进行的现场和卫星 SO2 测量结果来实现； (3) 对尼亚穆拉吉拉和尼拉贡戈历史喷发产物中的挥发物浓度和形态进行岩石学分析，以确定喷发期间岩浆脱气的程度。这些数据将与遥感 SO2 测量相结合，以评估一系列喷发事件中熔体硫损失与测量的 SO2 产量之间的关系；从而为非弧碱性火山过量硫排放的发生以及碱性玄武岩浆中硫和其他挥发物的行为提供了新的线索。这项研究的更广泛影响包括： 加强美国、非洲和欧洲团体之间的国际合作联系；对一名女研究生进行遥感、岩石学技术和实地考察方面的培训；为多年来遭受忽视和内乱的 GVO 非洲科学家提供宝贵的专业知识和合作活动；使用为该项目获取的卫星数据在戈马开展外展项目；并将奇异的火山岩成分添加到史密森学会的国家岩石收藏档案中，以供未来的研究工作。