现代海洋甲烷循环过程观测及研究进展

Observation and research progress of modern oceanic methane cycle

当前出于对全球气候变化的担心以及获取能源资源的需求,甲烷日渐成为人类社会关注的焦点。海洋中聚集了巨量的天然气水合物,存在与甲烷有关的多种重要生化作用,支持了海底繁盛的化能自养合成生物群落,有效调节了进入大气的甲烷通量,在全球碳循环中的地位无可替代。同时,因天然气水合物动态活动造成的甲烷泄漏是岩石圈向外部圈层进行物质和能量输送的重要途径,对海洋环境有着深远影响。系统介绍了现代海底甲烷泄漏的地质控制因素、沉积物和水体对富甲烷流体的消耗、海洋甲烷循环模拟研究以及全球典型海域甲烷观测及相关研究成果,最后指出了海洋甲烷循环研究发展趋势。综合考虑了环境、生物和技术因素对海洋甲烷循环的影响和限制,从一个地质工作者的视角对阶段成果和存在问题进行审视,并提出了自己的思考,借此引发全社会对与甲烷有关的重大科学问题及海洋观测技术的重视与支持。

Out of concern for global climate change and the demand for energy resources, methane has increasingly become the current focus of human society. A large amount of natural gas hydrate is stored in the ocean, which has many important biochemical reactions related to methane, supports the prosperous chemoautotrophic synthetic biological community on the seabed, effectively regulates the methane flux into the atmosphere, and plays an irreplaceable role in the global carbon cycle. At the same time, methane seepage caused by the dynamic activity of natural gas hydrate is a critical way to transport material and energy from the lithosphere to the outer sphere, which has a far-reaching impact on the marine environment. In this paper, we systematically introduce the geological control factors of modern seabed methane seepage, the consumption of methane by sediments and water columns, the simulation research of marine methane cycle, the methane observation and relevant research results in typical sea areas, and finally points out the development trend of marine methane cycle research. This review comprehensively considers the influence and limitation of environmental, biological and technological factors on the marine methane cycle,examines the temporary achievements and existing problems from the perspective of a geologist, and puts forward our own thinking, hoping to arouse the attention and support of the whole society to the major scientific problems related to methane and subsequent marine observation technology.