What Controls the CO2/SO2 Ratio in Arc Volcanic Gas?

是什么控制着电弧火山气体中的 CO2/SO2 比率？

• 批准号: 2017814
• 负责人: Terry Plank
• 金额: $ 25.74万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2017814&HistoricalAwards=false
• 关键词: What; Controls; CO2; SO2; Ratio

The degassing of carbon dioxide and sulfur from arc volcanoes is fundamentally important to eruption forecasting and cycling of volatiles through subduction zones. Measurements of carbon dioxide/sulfur dioxide in high-temperature volcanic gases have become the main approach to quantifying the arc volcanic carbon dioxide and sulfur outflux to the atmosphere. New high-rate, long-time series measurements of gas emissions from several volcanoes have now shown precursory signals in the rise of carbon dioxide/sulfur dioxide weeks before the eruption, which is typically considered to reflect deep, high pressure gas moving into the system. On the other hand, recent work has shown that volcanoes with intrinsically high carbon dioxide/sulfur dioxide gas ratios seem to correlate globally with regions of carbonate subduction. Such correlations have led to the suggestions that carbon dioxide/sulfur dioxide reflects the source of the parental magma. The source of variation in carbon dioxide/sulfur dioxide of magmatic gas is thus debated. This project aims at resolving the pressure vs. source effects on carbon dioxide/sulfur dioxide by providing novel data on the melt phase for volcanoes with published gas records. This project bears directly on the interpretation of carbon dioxide/sulfur gas precursors to volcanic eruptions, of relevancy to developing timely forecasts and warnings to local populations. This project will form the core of the postdoctoral project of an early-career female scientist at Lamont-Doherty Earth Observatory. It will also enable an undergraduate student to participate in the proposed research via an NSF-funded research experience for undergraduates program at Lamont-Doherty.Microanalysis of water, carbon dioxide, and sulfur in mineral-hosted melt inclusions can be a powerful tool for the study of carbon dioxide and sulfur degassing. However, vapor “shrinkage” bubbles present in melt inclusions can cause a significant underestimate of carbon dioxide contents in the bulk melt inclusion and lead to false estimates of degassing pressures and carbon dioxide outflux. The published melt inclusion database is rife with this issue. This project will constrain the carbon dioxide and sulfur contents in parental and degassing arc magmas by experimentally rehomogenizing olivine-hosted melt inclusions in the eruptive products from five volcanoes (San Cristóbal, Telica, Masaya, Poás and Turrialba) along the Costa Rica-Nicaragua volcanic arc. The rehomogenized melt inclusions will be used 1) to infer the carbon dioxide and sulfur contents of parental magmas (from basaltic end-members) and entrapment pressures (from water-carbon dioxide barometry), and 2) to calculate the coexisting fluid/vapor composition to compare with the volcanic gas data and to inform existing thermodynamic models. In this way, our data will test the extent to which the pressure of degassing versus the parental magma drive carbon dioxide/sulfur dioxide variations in arc volcanic gas, and quantify the origin of eruptive gas precursors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

弧火山二氧化碳和硫的脱水对于通过俯冲带的火山的喷发预测和循环至关重要。高温火山气体中二氧化碳/二氧化碳的测量已成为量化弧二氧化碳二氧化碳和硫磺出口的主要方法。现在，在喷发前几周，几周的二氧化碳/二氧化碳二氧化碳升高中显示了几个火山中的气体排放的新高速串联测量值，通常被认为反映了深压的高压气体进入系统。另一方面，最近的工作表明，具有本质上二氧化碳/硫二氧化硫气体比的火山似乎与碳酸盐俯冲区域有关。这种相关性导致了这样的建议：二氧化碳/二氧化碳反映了父母岩浆的来源。因此，对岩浆气体的二氧化碳/二氧化硫的变异来源进行了辩论。该项目旨在通过在火山的融化阶段提供新的数据，并通过发表的气体记录提供新的数据，以解决对二氧化碳/二氧化碳二氧化碳/二氧化碳的影响。该项目直接取决于将二氧化碳/硫的气体前体解释对火山喷发的解释，这与向当地人群开发及时的森林和警告有关。该项目将构成拉蒙特·霍蒂（Lamont-Doherty）地球天文台的早期女性科学家的博士后项目的核心。这也将使一名本科生能够通过Lamont-Doherty的NSF资助的本科计划的研究经验参加拟议的研究。水，二氧化碳和硫磺的微分析矿物质蜂蜜熔体融合物中的含量可以是对二氧化碳和硫化碳和硫磺含量的强大工具。然而，熔体夹杂物中存在的蒸气“收缩”气泡可能会导致大量融化含量的二氧化碳含量显着低估，并导致脱气压力和二氧化碳出口的错误估计。已发表的熔体包含数据库在此问题上被删除。 This project will constrain the carbon dioxide and sulfur contents in parental and degassing arc magmas by experimentally rehomogenizing olivine-hosted melt inclusions in the eruptive products from five volcanoes (San Cristóbal, Telica, Masaya, Poás and Turrialba) along the Costa Rica-Nicaragua volcanic arc.将使用重新调解的融合物1）来推断父母岩浆的二氧化碳和硫含量（来自玄武岩末端成员）和夹层压力（从二氧化二氧化物条形图），以及2），以计算与现有的液体/蒸汽组合物相比，将其与现有的模型相比。通过这种方式，我们的数据将测试脱气与父母岩浆的压力在弧火山气中驱动二氧化碳/二氧化碳的变化，并量化了喷发气体前体的起源。该奖项反映了NSF的法定任务，并通过评估智力的Merit和Broadial and crotia and croctia and croctia and Interviatial and Broadia and Sportial crrit and crarit和广泛的支持。

项目成果

Sulfur_X: A Model of Sulfur Degassing During Magma Ascent

Sulfur_X：岩浆上升过程中硫脱气的模型

• DOI: 10.1029/2022gc010552
• 发表时间: 2023
• 期刊: Geosystems
• 作者: Ding, Shuo;Plank, Terry;Wallace, Paul J.;Rasmussen, Daniel J.
• 通讯作者: Rasmussen, Daniel J.

Sulfur from the subducted slab dominates the sulfur budget of the mantle wedge under volcanic arcs

来自俯冲板片的硫主导了火山弧下地幔楔的硫收支

• DOI: 10.1016/j.epsl.2022.117948
• 发表时间: 2023
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Taracsák, Z.;Mather, T.A.;Ding, S.;Plank, T.;Brounce, M.;Pyle, D.M.;Aiuppa, A.
• 通讯作者: Aiuppa, A.

Limited sulfur degassing and muted environmental impact of Ontong Java Plateau lavas

翁通爪哇高原熔岩的硫脱气有限且环境影响较小

• DOI: 10.1130/g51283.1
• 发表时间: 2023
• 期刊: Geology
• 影响因子: 5.8
• 作者: Eguchi, James;Ding, Shuo;Black, Benjamin A.
• 通讯作者: Black, Benjamin A.