An integrated study of seepage through the seabed of the Nile deep-sea fan

尼罗河深海扇海底渗流综合研究

• 批准号: 5396044
• 负责人: Professorin Dr. Antje Boetius
• 金额: --
• 依托单位: Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2003
• 资助国家: 德国
• 起止时间: 2002-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5396044?language=en
• 关键词: integrated; study; seepage; through; seabed

At continental margins fluid and gases are emitted into the ocean via the seafloor. The forms of emissions extend from diffusive flow through the seafloor, to focussed flow through seeps and vents, and can be highly variable in time and space. Fluid seeps are highly dynamic sites where geosphere, biosphere, hydrosphere and atmosphere are linked. Seep fluids (liquids and gases) include hydrocarbons, carbon dioxide, nitrogen and hydrogen sulfide, in addition to water. These energy sources support distinct biological communities and chemosynthetic organisms. Currently, the global inventory of fluid seeps at passive continental margins is growing rapidly, but geological, chemical and biological processes operating at those fluid seeps remain little known. In this regard, important research tasks are deriving methane fluxes in their relevance to climatic changes, evaluation of fluid-triggered instabilities on continental slopes, and hydrocarbon geochemical prospecting in the deep offshore. MEDIFLUX proposes a comprehensive, transdisciplinary investigation of fluid seepage at a site exemplarily rich in a large variety of fluid escape structures on a passive continental margin, the Nile deep-sea fan. Objectives are (1) to describe the geographical distribution, types, geological formation and activity of fluid seeps of the Nile deep-sea fan, (2) to determine the composition of emitted fluids and use this information to infer fluid properties and fluid processes at depth, (3) to understand the controls and mechanisms of chemical element transport and breakdown by seep biota, and to obtain a well constrained budget of element cycling and export at fluid seeps.

在大陆边，流体和气体通过海底排入海洋。排放的形式从通过海底的扩散流到通过渗漏和喷口的集中流，在时间和空间上变化很大。流体渗漏是地圈、生物圈、水圈和大气相互联系的高度动态场所。渗漏流体（液体和气体）除水外，还包括碳氢化合物、二氧化碳、氮气和硫化氢。这些能源支持不同的生物群落和化能合成生物。目前，全球被动大陆边的流体渗漏正在迅速增加，但对这些流体渗漏的地质、化学和生物过程知之甚少。在这方面，重要的研究任务是推导甲烷通量与气候变化的关系，评估大陆斜坡上流体引发的不稳定性，以及深海碳氢化合物地球化学勘探。MEDIFLUX提出了一个全面的，跨学科的调查，在现场的流体渗漏，典型地丰富的各种流体逃逸结构的被动大陆边缘，尼罗河深海扇。目的是（1）描述尼罗河深海扇流体渗漏的地理分布、类型、地质形成和活动;（2）确定排放流体的组成，并利用这些信息推断深部流体性质和流体过程;（3）了解渗漏生物群对化学元素迁移和分解的控制和机制，并在流体渗漏处获得元素循环和输出的良好约束的预算。