Sediment Imaging with Autonomous Underwater Vehicles: A Community Tool

使用自主水下航行器进行沉积物成像：社区工具

• 批准号: 1754419
• 负责人: Ross Parnell-Turner
• 金额: $ 9.89万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1754419&HistoricalAwards=false
• 关键词: Sediment; Imaging; Autonomous; Underwater; Vehicles

The deepest parts of Earth's oceans are remote and difficult to explore. Thus, the geological, biological, and chemical processes taking place there remain poorly understood. Advances in autonomous underwater vehicle (AUV) technology in the past decade mean that we can now send these vehicles to the seabed in water depths of several miles where they collect data from just above the seafloor. AUVs are often equipped with a high-resolution compressed-high intensity pulse (CHIRP) sonar, which can capture centimeter-scale-resolution, cross-section images of the sediment that blankets the seafloor. These thicknesses can then be used as proxies for the length of time a feature has been exposed on the seafloor. Despite this potential, time constraints and a lack of an easily available sonar data processing scheme means that these CHIRP data are often under-utilized. This research develops a standard workflow and software for processing EdgeTech CHIRP sonar data, for use both at sea and on shore, using already existing AUV-acquired CHIRP surveys of sediment from a specific location on the Mid-Atlantic Ridge and other associated imaging data. Application of the processed data will be used to measure sediment thickness in an area where knowledge of this parameter advances our understanding of the interplay between the faulting and volcanism at mid-ocean ridge axes. Broader impacts of the research add value and capability to the existing US AUV fleet and advance our understanding of crustal formation at mid-ocean ridges. The methods and outcomes of the work will be incorporated into professional development workshops for in-service teachers in the highly diverse San Diego Unified School District, providing resources for lessons that can be widely used throughout the school system and support an early career investigator.In areas far from terrestrial sources, sediment thickness in deep sea marine environments is a rough proxy for the amount of time a feature has been exposed on the seabed. Thus, this provides a way to constrain the timing of geological events, such as volcanic eruptions and/or slip on faults. At young features, such as mid-ocean ridges axial valleys, sediment is typically only a few meters thick and so cannot be picked up by other shipboard geophysical/seismic imaging tools. These sediment thicknesses, at present, can only be imaged using near-bottom sonars such as those carried by AUVs. Use of these tools is particularly useful at slow-spreading mid-ocean ridges where the interplay between low-angle faults, know as detachments, and volcanism remains poorly understood. Although it is now clear that vast areas of seafloor are created under the influence of detachment faults, the relationships between detachments and magmatism and melt supply remain uncertain. This project uses already existing CHIRP data, acquired during fourteen dives of AUV Sentry at latitude 16.5°N on the Mid-Atlantic Ridge in 2013. Research goals are to provide new CHIRP processing protocols that can be used to more quickly process CHIRP sonar data and to use the existing data to quantitatively determine variations in sediment thickness and, thus, establish the relative timing of detachment fault slip and volcanism in the study area. The research adds significant value to an existing dataset that was acquired in an inaccessible part of the deep ocean and will deliver an open-source software tool to the scientific community and the public in a cost-effective way.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

地球海洋最深的部分是遥远的，难以探索。那是那里发生的地质，生物学和化学过程，仍然不太了解。在过去的十年中，自动驾驶水下车辆（AUV）技术的进步意味着我们现在可以将这些车辆送到海床的水深处，在几英里处，它们从海底上方收集数据。 AUV通常与高分辨率的压缩高强度脉冲（CHIRP）声纳相等，该声纳可以捕获覆盖海底的沉积物的千分表分辨率，横截面图像。然后可以将这些厚度用作代理，因为该特征已在海底暴露于特征的时间长度上。尽管有潜力，但时间限制和缺乏易于获得的声纳数据处理方案意味着这些chirp数据通常被低估了。这项研究开发了用于处理Edgetech Chirp声纳数据的标准工作流程和软件，用于在海上和岸上使用，并使用已经现有的AUV获得的se架调查从中大西洋山脊和其他相关成像数据的特定位置进行了沉积物调查。处理后的数据的应用将用于测量在此参数知识促进我们对中山脊轴断层和火山之间相互作用的了解的区域中的沉积物厚度。研究的更广泛的影响为现有的美国AUV车队增加了价值和能力，并提高了我们对中山脊的地壳形成的理解。 The methods and outcomes of the work will be incorporated into professional development workshops for in-service teachers in the highly divers San Diego Unified School District, providing resources for lessons that can be widely used throughout the school system and support an early career investigator.In areas far from terrestrial sources, sediment thickness in deep sea marine environments is a rough proxy for the amount of time a feature has been exposed on the seabed.这是一种方法来限制地质事件的时机，例如火山喷发和/或在断层上滑落。在年轻的特征（例如中山脊）轴向山谷等年轻特征下，沉积物通常只有几米厚，因此无法被其他船舶地球物理/地震成像工具捡起。目前，这些沉积物厚度只能使用近乎底部的声纳（例如AUV携带的声音）进行成像。这些工具的使用在慢速范围内山脊上特别有用，在慢速海洋脊中，低角度断层之间的相互作用，被称为脱离和火山，人们对此的了解仍然很差。尽管现在很明显，海底的大部分地区是在支队断层的影响下创建的，但脱离与岩浆和熔融供应之间的关系仍然不确定。 This project uses already existing CHIRP data, acquired during fourteen dives of AUV Sentry at latitude 16.5°N on the Mid-Atlantic Ridge in 2013. Research goals are to provide new CHIRP processing protocols that can be used to more quickly process CHIRP sonar data and to use the existing data to quantitatively determine variations in sediment thickness and thus, establish the relative timing of detachment fault slip and volcanism in the study area.这项研究为现有数据集增加了重要价值，该数据集是在深海无法访问的部分中获得的，并将以具有成本效益的方式向科学界和公众提供开源软件工具。该奖项反映了NSF的法定任务，并通过使用该基金会的智力功能和广泛的影响来评估NSF的法定任务，并被视为珍贵的支持。

项目成果

The Final Stages of Slip and Volcanism on an Oceanic Detachment Fault at 13°48′N, Mid-Atlantic Ridge

大西洋中脊北纬 13°48° 处海洋滑脱断层上滑动和火山活动的最后阶段

• DOI: 10.1029/2018gc007536
• 发表时间: 2018
• 期刊: Geosystems
• 作者: Parnell-Turner, R. E.;Mittelstaedt, E.;Kurz, M. D.;Jones, M. R.;Soule, S. A.;Klein, F.;Wanless, V. D.;Fornari, D. J.
• 通讯作者: Fornari, D. J.