Dynamics of Gas Hydrates and Permafrost in the Eurasian and North American Arctic Land-Shelf System

欧亚和北美北极陆架系统中天然气水合物和多年冻土的动态

• 批准号: 9985826
• 负责人: Thomas Osterkamp
• 金额: $ 19.46万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9985826&HistoricalAwards=false
• 关键词: Dynamics; Gas; Hydrates; Permafrost; Eurasian

AbstractOPP-998586OsterkampMethane hydrates occur when methane and water exist in close proximity at low temperatures and elevated pressures. These conditions are present in permafrost regions and beneath the sea along the outer continental margins. Consequently, methane hydrates are thought to be widespread in the onshore permafrost regions of the North American and the Russian Arctic and in the shallow continental shelves of the Arctic Ocean where subsea permafrost is found. These gas hydrates are a potential and abundant source of energy, a major sink for global carbon, and could influence seafloor stability.Low sea levels 20,000 years ago exposed the shallow continental shelves of the Arctic Ocean to the cold climate, allowing permafrost and stable gas hydrates to form in these shelves. Climatic warming and changes in sea level warm the permafrost and destabilize the hydrates. Methane gas is produced during hydrate destabilization and may eventually be released to the atmosphere. Permafrost temperatures are known to have increased 2-4oC during this century and current climatic models predict continued warming. With present knowledge, it is not possible to predict the amount or timing of methane releases by gas hydrate decomposition as a result of permafrost, especially subsea permafrost, degradation.The Principal Investigators will survey existing data on gas hydrate and permafrost conditions in the Russian Arctic land-shelf system to establish boundary conditions, properties, occurrence and distribution. This information will be used as in the future as input data for a two dimensional numerical model of gas hydrates and permafrost. A model was developed by the Principal Investigators in the late 1980s and modified in the early 1990s specifically for studies of permafrost, subsea permafrost and gas hydrates over long time scales. The Principal Investigators will collect and synthesize existing data on the occurrence of gas hydrate in permafrost on the Russian Arctic land-sea margin. The data will be evaluated for reliability, standardized, and translated into English. This project will address the synergism between gas hydrates, climate and sea level and help to increase our understanding of how gas hydrates destabilize over geological time scales. The research will be conducted jointly by the Geophysical Institute and Russian investigators.

摘要OPP-998586 Osterkamp当甲烷和水在低温和高压下紧邻存在时，就会产生甲烷水合物。 这些条件存在于永久冻土区和沿着外大陆边的海底。 因此，甲烷水合物被认为广泛存在于北美和俄罗斯北极地区的陆上永久冻土区，以及存在海底永久冻土的北冰洋浅大陆架。这些气体水合物是一种潜在的丰富能源，是全球碳的主要汇，并可能影响海底稳定性。2000年前，北冰洋的浅大陆架暴露在寒冷的气候中，使永久冻土和稳定的天然气水合物在这些大陆架中形成。 气候变暖和海平面的变化使永久冻土层升温，使水合物不稳定。 甲烷气体是在水合物去稳定过程中产生的，并最终可能被释放到大气中。已知永久冻土温度在本世纪上升了2- 4摄氏度，目前的气候模型预测将继续变暖。 目前的知识，这是不可能预测的数量或时间的甲烷释放的天然气水合物分解的结果，永久冻土，特别是海底永久冻土，degradation.The首席调查员将调查现有的数据，天然气水合物和永久冻土条件在俄罗斯北极大陆架系统，以建立边界条件，属性，发生和分布。 这一信息将被用来作为在未来的输入数据的二维数值模型的天然气水合物和冻土。 主要研究人员在1980年代末开发了一个模型，并在1990年代初进行了修改，专门用于长期研究永久冻土、海底永久冻土和天然气水合物。 主要研究人员将收集和综合俄罗斯北极陆海边缘永久冻土中天然气水合物存在的现有数据。 将评估数据的可靠性、标准化并翻译成英文。 该项目将解决天然气水合物、气候和海平面之间的协同作用，并有助于提高我们对天然气水合物如何在地质时间尺度上不稳定的理解。 这项研究将由地球物理研究所和俄罗斯调查人员联合进行。