Mackenzie Delta thermogenic methane distribution, sources, drivers

麦肯齐三角洲产热甲烷分布、来源、驱动因素

• 批准号: RGPIN-2019-06006
• 负责人: Risk, Dave
• 金额: $ 2.62万
• 依托单位: St. Francis Xavier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=686692
• 关键词: Mackenzie; Delta; thermogenic; methane; distribution

Relative to surface biologic production of methane from soils, wetlands, and degrading permafrost, geologic seeps of methane are less well understood. We know that a large amount of methane is emitted from natural geologic seepage, venting oil and gas reservoirs or subsurface gas hydrates. Sporadic studies over the past two decades from provincial and federal scientists have identified huge natural seeps in the Mackenzie Delta. New aircraft studies suggest that geological seepage hotspots are a dominant control on landscape emissions, and that water body sources in the Mackenzie Delta were not the hotspots most global land surface models would expect. This leaves an uncomfortable friction between geologically-based estimates, and the findings of ecosystem scientists working elsewhere in the Arctic who conclude that warming temperatures and a deepening active layer drives increased methane production in large part from water bodies. Are geological emissions of methane in the Mackenzie Delta as prolific as new studies suggest? Could this be happening elsewhere, and do we need to revise our approach to studying Arctic methane?******My proposed research aims to understand geological methane distribution, sources, and drivers in the Mackenzie Delta. The research will focus on collecting data at landscape scales, since the debates are inherently about landscape distribution of sources. The research will involve a mixture of graduate students, undergraduates, and research associates, working alongside identified academic, government, and industry collaborators specialized in Mackenzie Delta methane and related issues (permafrost degradation, petroleum systems, geochemistry, measurement tools). To identify emission hotspots, we will apply landscape-scale (100s km) geochemical survey tools, in combination with satellite data. Within these areas we will undertake detailed investigations of sources and geochemistry, in an effort to understand local distribution, relative rates, and drivers of geological seeps and surface biogenic activity. This research is a natural extension of my experience in oil and gas tracer studies, cold-regions biogenic soil gas studies (including recent work in the Mackenzie Delta), and my keen interest in landscape-scale gas measurement methodologies, which for the first time will come together in a single project.******The results of this interdisciplinary work will be useful for atmospheric scientists, climate modelers, permafrost soil scientists, and geologists interested in petroleum systems and the long-term carbon cycle. Because there is also some focus on identifying biogenic methane, there is the possibility to link this work to permafrost thaw and decomposition of organics, methane from organic-loaded hydrologic systems, and landscape change (thaw-driven landslides, slumps). This research is also designed to connect with the NASA Arctic Boreal Vulnerability Experiment (ABoVE), in which I play a continuing role.**

相对于土壤、湿地和退化永久冻土中的地表生物甲烷生产，甲烷的地质渗漏尚不清楚。 我们知道，大量的甲烷是由自然地质渗漏、油气藏或地下天然气水合物排放而排放的。 过去二十年来，省和联邦科学家进行的零星研究发现，麦肯齐三角洲存在巨大的天然渗漏点。新的飞机研究表明，地质渗漏热点是景观排放的主要控制因素，而麦肯齐三角洲的水体来源并不是大多数全球陆地表面模型所预期的热点。这在基于地质的估计和在北极其他地方工作的生态系统科学家的发现之间留下了令人不安的摩擦，他们得出的结论是，气温升高和活动层加深导致很大程度上来自水体的甲烷产量增加。麦肯齐三角洲的地质甲烷排放是否像新研究表明的那样大量？这种情况是否会发生在其他地方，我们是否需要修改研究北极甲烷的方法？******我提出的研究旨在了解麦肯齐三角洲的地质甲烷分布、来源和驱动因素。 该研究将侧重于收集景观尺度的数据，因为争论本质上是关于源的景观分布。该研究将涉及研究生、本科生和研究助理，与专门研究麦肯齐三角洲甲烷及相关问题（永久冻土退化、石油系统、地球化学、测量工具）的学术界、政府和行业合作者一起工作。为了识别排放热点，我们将结合卫星数据应用景观尺度（百公里）地球化学调查工具。在这些区域内，我们将对来源和地球化学进行详细调查，以了解当地分布、相对速率以及地质渗漏和地表生物活动的驱动因素。这项研究是我在石油和天然气示踪剂研究、寒冷地区生物土壤气体研究（包括最近在麦肯齐三角洲的工作）方面的经验的自然延伸，也是我对景观尺度气体测量方法的浓厚兴趣，这是我第一次将汇集在一个项目中。******这项跨学科工作的结果将对大气科学家、气候建模者、永久冻土科学家以及对石油系统和长期碳循环感兴趣的地质学家有用。由于也有一些重点放在识别生物甲烷上，因此有可能将这项工作与永久冻土融化和有机物分解、来自有机负荷水文系统的甲烷以及景观变化（解冻驱动的山体滑坡、滑坡）联系起来。 这项研究还旨在与 NASA 北极寒带脆弱性实验 (ABoVE) 联系起来，我在其中持续发挥作用。**