• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文OA文献 >Arctic Nearshore Sediment Dynamics from High-Resolution Phase Measuring Bathymetric Sonar Data: bathymetry, backscatter imagery, and seabed classification
【2h】

Arctic Nearshore Sediment Dynamics from High-Resolution Phase Measuring Bathymetric Sonar Data: bathymetry, backscatter imagery, and seabed classification

机译：高分辨率相位测量测深声纳数据的北极近岸沉积动力学：水深测量，反向散射图像和海底分类

页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Carbon-rich permafrost coasts in the Arctic are subject to rapid erosion, causing vast quantities of carbon and sediments to enter the nearshore. According to many climate models, the Arctic will experience disproportionate warming in coming decades. One of the consequences will be increased coastal erosion, as the open water season lengthens. The release of carbon raises a number of questions ranging from the impact on local ecosystems, to potential climate change feedbacks. Due to the size and remoteness of arctic coasts, relatively few studies addressed the question of carbon transfer into the Arctic Ocean. These studies rely on remotely sensed data which means that the submarine portion of the coast, the processes and storage potential remain largely unknown. The Coastal Permafrost Erosion project by the Alfred Wegener Institute aims to answer some of these questions by quantifying erosion and characterizing eroded material for the whole coastal tract in the vicinity of Herschel Island, Yukon Territory, Canada. In this study, we describe the investigations of nearshore sediment and carbon dynamics carried out as part of the project in 2012 and 2013. The objective of the study is to establish a baseline dataset on bottom sediments, and gain insight into transport processes, pathways, and sinks. ud Phase Measuring Bathymetry allows to collect co-registered high-resolution bathymetry and side scan sonar data. The system chosen was a 500kHz system, which provided optimum coverage for the water depths of the reference area. The bathymetric data provided insight into physical processes such as ice gouging (Fig. 1), while compensated side scan mosaics delivered a map of sediment distribution (Fig. 2). The side scan data was processed, mosaicked and classified using the software tools provided by the sonar manufacturer, as well as the bathymetry. For the present study, both were gridded at 0.5 m resolution. udThrough the compensated backscatter imagery, we identified areas where fine sediments are deposited and carbon may be stored. The classified seafloor image was validated by grain size parameters from the benthic grab samples with a very high degree of correlation. A significant portion of the released carbon is particulate organic matter which is transported along with the sediment. Elemental analysis of the grab samples revealed that organic carbon may account for up to 9% of the bottom sediment. We also found that the shoreface is subject to intensive ice gouging. Finally, we found that the sediment distribution in the nearshore is related to terrestrial features being eroded, e.g. cliffs, or valleys.ud
机译：北极富碳的多年冻土海岸易遭受快速侵蚀，导致大量碳和沉积物进入近岸。根据许多气候模型，在未来几十年中，北极将经历不成比例的变暖。随着开放水期的延长，后果之一将是沿海侵蚀加剧。碳的释放提出了许多问题，从对当地生态系统的影响到潜在的气候变化反馈。由于北极海岸的规模和偏远地区，很少有研究解决碳向北冰洋转移的问题。这些研究依赖于遥感数据，这意味着海岸的海底部分，过程和储藏潜力仍然未知。阿尔弗雷德·韦格纳研究所（Alfred Wegener Institute）开展的沿海多年冻土侵蚀项目旨在通过量化侵蚀并对加拿大育空地区赫舍尔岛附近整个沿海地区的侵蚀物质进行特征分析来回答其中的一些问题。在这项研究中，我们描述了作为该项目的一部分在2012年和2013年进行的近岸沉积物和碳动力学的调查。研究的目的是建立底层沉积物的基线数据集，并深入了解运输过程，途径，和下沉。 ud相位测量测深仪可以收集共同注册的高分辨率测深仪和侧面扫描声纳数据。选择的系统是500kHz系统，它为参考区域的水深提供了最佳覆盖范围。水深数据提供了对物理过程（如冰刨）的洞察力（图1），而经补偿的侧面扫描镶嵌图提供了沉积物分布图（图2）。使用声纳制造商提供的软件工具以及测深法对侧面扫描数据进行处理，镶嵌和分类。对于本研究，两者均以0.5 m的分辨率网格化。 ud通过补偿后向散射图像，我们确定了细小沉积物沉积和碳可以存储的区域。通过底栖抓斗样品的粒度参数验证了分类的海底图像，这些参数具有很高的相关度。释放出的大部分碳是与沉积物一起运输的颗粒状有机物。抓斗样品的元素分析表明，有机碳可能占底部沉积物的9％。我们还发现，该岸面受到强烈的冰刨。最后，我们发现近岸的沉积物分布与被侵蚀的陆地特征有关，例如悬崖或山谷。 ud

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号