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.

弧火山中二氧化碳和硫的脱气对于俯冲带的喷发预测和挥发物循环至关重要，高温火山气体中二氧化碳/二氧化硫的测量已成为量化弧火山二氧化碳和硫的主要方法。对几座火山气体排放的新的高速率、长期系列测量现已显示出碳上升的先兆信号。喷发前几周，这通常被认为反映了深层高压气体进入系统。另一方面，最近的研究表明，具有内在高二氧化碳/二氧化硫气体比率的火山似乎在全球范围内具有相关性。这种相关性导致人们认为二氧化碳/二氧化硫反映了母岩浆的来源，因此，该项目的目的是争论岩浆气体的二氧化碳/二氧化硫的变化来源。通过提供已发表的气体记录的火山融化阶段的新数据，解决压力与来源对二氧化碳/二氧化硫的影响。该项目直接关系到对火山喷发的二氧化碳/硫气体前体的解释，与发展相关。该项目将构成拉蒙特-多尔蒂地球观测站一名早期职业女科学家的博士后项目的核心，它还将使一名本科生能够参与拟议的项目。通过国家科学基金会资助的拉蒙特-多尔蒂本科生项目的研究经验，对矿物熔体包裹体中的水、二氧化碳和硫进行微量分析可以成为研究二氧化碳和硫脱气的有力工具。熔体夹杂物中存在的“收缩”气泡会导致大块熔体夹杂物中二氧化碳含量的显着低估，并导致脱气压力和二氧化碳流出量的错误估计。已发布的熔体数据库夹杂物是。该项目将通过实验性地重新均匀化沿线五座火山（圣克里斯托瓦尔火山、泰利卡火山、马萨亚火山、波阿斯火山和图里亚尔巴火山）喷发产物中的橄榄石熔体包裹体，来限制母岩浆和脱气弧岩浆中的二氧化碳和硫含量。哥斯达黎加-尼加拉瓜火山弧。重新均质的熔体包裹体将用于 1) 推断二氧化碳和硫含量。母体岩浆（来自玄武岩端元）和俘获压力（来自水-二氧化碳气压计），以及 2) 计算共存的流体/蒸汽成分，与火山气体数据进行比较，并以这种方式为现有的热力学模型提供信息。 ，我们的数据将测试脱气压力与母岩浆驱动弧火山气体中二氧化碳/二氧化硫变化的程度，并量化喷发气体前体的起源。该奖项反映通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。

项目成果

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: 2023-01
• 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.;EIMF
• 通讯作者: EIMF

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: 2023-07
• 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.

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: 2023-04
• 期刊: Geosystems
• 作者: Ding, Shuo;Plank, Terry;Wallace, Paul J.;Rasmussen, Daniel J.
• 通讯作者: Rasmussen, Daniel J.