Quantitative morphologic analysis of pockmarks around Barkley Canyon (NE Pacific): spatial and temporal evolution and formation mechanisms

巴克利峡谷（太平洋东北部）周围麻点的定量形态分析：时空演化和形成机制

• 批准号: 448793099
• 负责人: Dr. Jacob Geersen
• 金额: --
• 依托单位: Arbeitsgruppe Marine Geophysik und Hydroakustik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/448793099?language=en
• 关键词: Quantitative; morphologic; analysis; pockmarks; around

Pockmarks are crater-like depressions in marine or lacustrine sediments. They are often interpreted as the surface manifestation of hydrocarbon venting but may also result from freshwater flow in coastal regions, compaction induced sediment dewatering, or bottom scouring around natural or anthropogenic objects. Hence, they can be of relevance for the global carbon cycle, offshore infrastructure, benthic life, and slope stability. Pockmarks and associated gas-bubbles in the water-column can be mapped with modern ship-based multibeam systems. However, to understand their relevance for geologic and hydrodynamic processes in the oceans, repeated and multi-disciplinary data sets are necessary that resolve their formation mechanism and transient seep activity. Owing to the presence of a large cabled underwater observatory, a wealth of multi-resolution and multi-disciplinary seafloor data is available from a recently discovered huge pockmark field at Barkley Canyon (Canada). Available data include repeated multibeam surveys, seafloor video footage, seismic and EK60 echo-sounder profiles, dredged boulders from the pockmarks, and multibeam water-column information. Many of these data sets have been collected repeatedly over the last 10 years. I will use this data to analyse, for the first time, how the distribution, morphology and seepage activity of a pockmark field has developed over a period of ten years. The results will allow formulating a comprehensive model that puts the Barkley Canyon pockmarks into the regional geological and hydrodynamical context and that will help to better understand the processes that control pockmark formation and activity globally.Pockmark fields, including the one around Barkley Canyon, typically yield several hundreds to thousands of pockmarks. This abundance constitutes a challenge for their analysis, but also a great opportunity for statistical evaluation. In order to support analyses of the Barkley Canyon pockmark field, I will create automated workflows that are able to map and characterize large numbers of morphologic features in digital elevation models. All morphologic workflows will be made publicly available for automated mapping and classification of large numbers of concentric features in digital elevation models.

麻点是海洋或湖泊沉积物中类似火山口的凹陷。它们通常被解释为碳氢化合物排放的表面表现，但也可能是由沿海地区的淡水流、压实引起的沉积物脱水或自然或人为物体周围的底部冲刷造成的。因此，它们与全球碳循环、海上基础设施、海底生物和边坡稳定性具有相关性。水柱中的麻点和相关气泡可以使用现代船基多波束系统进行绘制。然而，为了了解它们与海洋地质和水动力过程的相关性，需要重复的多学科数据集来解决它们的形成机制和瞬态渗流活动。由于大型有线水下观测站的存在，可以从巴克利峡谷（加拿大）最近发现的巨大麻点区域获得大量多分辨率和多学科海底数据。可用数据包括重复的多波束勘测、海底视频片段、地震和 EK60 回声测深仪剖面、从麻点中挖出的巨石以及多波束水柱信息。其中许多数据集是在过去 10 年中反复收集的。我将首次利用这些数据来分析十年来麻点场的分布、形态和渗流活动是如何发展的。研究结果将有助于制定一个综合模型，将巴克利峡谷麻点纳入区域地质和流体动力学背景，这将有助于更好地了解控制全球麻点形成和活动的过程。麻点区域，包括巴克利峡谷周围的区域，通常会产生数百至数千个麻点。这种丰富性对他们的分析构成了挑战，但也是统计评估的绝佳机会。为了支持巴克利峡谷麻点场的分析，我将创建自动化工作流程，能够在数字高程模型中绘制和表征大量形态特征。所有形态工作流程都将公开，用于数字高程模型中大量同心要素的自动映射和分类。