Mapping and Quantifying Methane Seeps on the Eastern Siberian Shelf and Slope -- A Component of the Swedish Russian U.S. Climate-Cryosphere-Carbon Interactions (SWERUS-C3) Program

绘制和量化东西伯利亚大陆架和斜坡上的甲烷渗漏——瑞典俄罗斯美国气候-冰冻圈-碳相互作用（SWERUS-C3）计划的一部分

• 批准号: 1417789
• 负责人: Larry Mayer
• 金额: $ 29.07万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417789&HistoricalAwards=false
• 关键词: Mapping; Quantifying; Methane; Seeps; Eastern

Methane is a potent greenhouse gas that is present in large amounts in frozen soils and marine sediments in the Arctic. In marine sediments, methane may be present either in permafrost or in gas hydrates. Warming of the Arctic may lead to the release of stored methane, leading to further warming and then to further methane releases in a reinforcing cycle. The East Siberian Sea, in the Arctic Ocean, is a large area with a great deal of undersea permafrost and, likely, stored methane. Recent work has suggested large sources of methane from parts of the East Siberian Sea, but the area needs to be mapped and studied in much greater detail before either the amount of methane stored there or the amount being released can be fully understood. In the summer of 2014, an international program called the Swedish-Russian-US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions (SWERUS-C3) will undertake a 90-day expedition to map, and study the carbon cycle in, the East Siberian Sea. The principal investigators of this proposal are leaders in ocean mapping and they have recently pioneered techniques for acoustic imaging of methane plumes released from the seafloor in the Gulf of Mexico. They have been invited by the leaders of the SWERUS-C3 team to participate in one leg of the expedition. They propose to use the multibeam sonar on board the ODEN to locate and characterize gas seeps in the water column and then apply a newly developed wideband transceiver to the split-beam echosounder on board the ODEN to constrain the size and fate of gas bubbles rising to the surface. Together, these acoustic observations will help the SWERUS-C3 team understand the flux of methane from the seafloor into the water column and potentially into the atmosphere. If successful, these techniques will allow the mapping of the gas flux in the Arctic over scales never before possible. This proposal requests support for the participation of the UNH team on this expedition and for post-cruise work-up of the data. The project will support a full time graduate student at UNH. A UNH undergraduate student will participate as well. The SWERUS-C3 program as a whole will support over 15 postdoctoral researchers and graduate students, and has a broad suite of outreach activities planned. The UNH Center for Coastal Ocean Mapping will also incorporate this work into ongoing outreach and education activities.

甲烷是一种强效温室气体，大量存在于北极的冻土和海洋沉积物中。在海洋沉积物中，甲烷可能存在于永久冻土或天然气水合物中。北极变暖可能导致储存的甲烷释放，导致进一步变暖，然后在强化循环中进一步释放甲烷。北冰洋的东西伯利亚海面积很大，有大量海底永久冻土，并且可能储存有甲烷。最近的研究表明，东西伯利亚海部分地区存在大量甲烷来源，但在充分了解该地区储存的甲烷量或释放量之前，需要对该地区进行更详细的绘图和研究。 2014 年夏天，一项名为“瑞典-俄罗斯-美国北冰洋气候-冰冻圈-碳相互作用调查”(SWERUS-C3) 的国际计划将进行为期 90 天的考察，绘制东部地区的碳循环图并进行研究西伯利亚海。该提案的主要研究人员是海洋测绘领域的领导者，他们最近开创了对墨西哥湾海底释放的甲烷羽流进行声学成像的技术。他们受到SWERUS-C3团队领导的邀请，参加了本次探险的其中一站。他们建议使用 ODEN 上的多波束声纳来定位和表征水柱中的气体渗漏，然后将新开发的宽带收发器应用于 ODEN 上的分波束回声测深仪，以限制气泡上升到表面。总之，这些声学观测将帮助 SWERUS-C3 团队了解甲烷从海底进入水柱并可能进入大气的通量。如果成功，这些技术将能够以前所未有的规模绘制北极的气体通量图。该提案请求支持 UNH 团队参与本次探险以及巡航后的数据处理。该项目将支持新罕布什尔大学的一名全日制研究生。新罕布什尔大学的一名本科生也将参加。 SWERUS-C3 项目作为一个整体将支持超过 15 名博士后研究人员和研究生，并计划开展一系列广泛的外展活动。新罕布什尔大学沿海海洋测绘中心也将把这项工作纳入正在进行的外展和教育活动中。