Northern Depths of the Great Barrier Reef bathymetry survey (FK200930/GA4866)

This resource includes bathymetry data acquired during the Northern Depths of the Great Barrier Reef survey on RV Falkor using its Kongsberg EM302 multibeam sonar system. The EM710 data acquired on this survey will be included in a future release.The primary objective of the survey was to explore the Cape York Peninsula region, through geophysical mapping of the shelf edge and continental slope adjacent to the barrier reefs and around the seven detached reefs lying north of Cape Weymouth, including within the large Wreck Bay. The offshore Cape York area is considered a frontier marine region with very little multibeam data collected previously in this far northern section of the Great Barrier Reef. The survey aimed to reveal the full inventory of submarine canyons, drowned reefs and any other significant seabed features in the region.A secondary objective was to conduct geophysical mapping of the Swain slide, an underwater landslide on the slope adjacent to the Swain Reefs in the southern Great Barrier Reef, with a headscarp about 10 km wide and a debris field extending ~20 km from the headscarp. The mapping aimed to reveal the full extent of the debris field and nature of the debris material proximal to the headscarp.Another objective was to conduct geophysical mapping around the steeper slopes around reefs in the eastern Coral Sea Marine Park, including the Saumarez, Frederick, Kenn, Wreck and Cato Reefs. The mapping aimed to fill data gaps between existing airborne LIDAR bathymetry over the shallow reefs and previously collected multibeam data around the steeper flanks. To achieve these objectives, the survey extended over 47 days, leaving Brisbane, Australia on September 30, 2020 and returning to Brisbane, Australia on November 17, 2020. The voyage was split into three legs, with port calls made at Cairns and Horn Island in the Torres Strait.Geophysical mapping involved the use of both Kongsberg EM302 and EM710 multibeam systems on the RV Falkor, typically operated in Dual Swath mode. In depths deeper than ~1200 m, the EM710 was turned off. Backscatter and water column data were also collected on both multibeam systems.This V1 dataset contains two 64m resolution 32-bit geotiff files of the FK200930 survey area produced from the processed EM302 only bathymetry data.This dataset is not to be used for navigational purposes.This dataset is published with the permission of the CEO, Geoscience Australia.本数据集包含“Falkor号”科考调查船（RV Falkor）在大堡礁北部海域调查中采集的水深测绘数据（bathymetry data），作业期间使用了船上搭载的康斯伯格EM302多波束声呐系统（Kongsberg EM302 multibeam sonar system）。本次调查采集的EM710数据将在后续版本发布。 本次调查的核心目标为对约克角半岛（Cape York Peninsula）周边海域开展地球物理测绘，覆盖珊瑚礁群毗邻的陆架边缘与大陆坡区域，以及韦茅斯角（Cape Weymouth）以北的7座独立珊瑚礁周边海域，其中包含大型沉船湾（Wreck Bay）内部区域。约克角半岛外海属于前沿海洋勘探区域，此前在大堡礁最北部海域采集的多波束数据极为匮乏。本次调查旨在全面摸清该区域内的海底峡谷、淹没珊瑚礁及其他重要海底地形特征。 本次调查的次要目标为开展斯温滑坡（Swain slide）的地球物理测绘：该水下滑坡位于大堡礁南部斯温珊瑚礁毗邻的大陆坡上，其滑坡壁（headscarp）宽度约10千米，碎屑堆积区（debris field）距滑坡壁延伸约20千米。本次测绘旨在明确碎屑堆积区的完整分布范围，以及滑坡壁附近碎屑物质的物理性质。 另一项调查目标为对珊瑚海海洋公园东部区域的珊瑚礁陡坡周边海域开展地球物理测绘，涵盖索马雷兹礁（Saumarez Reef）、弗雷德里克礁（Frederick Reef）、肯恩礁（Kenn Reef）、沉船礁（Wreck Reef）与卡托礁（Cato Reef）。本次测绘旨在填补浅礁区域现有机载激光雷达水深测绘（airborne LIDAR bathymetry）数据与陡坡周边既往采集的多波束数据之间的数据空白。 为达成上述目标，本次调查持续47天，于2020年9月30日从澳大利亚布里斯班起航，最终于2020年11月17日返回布里斯班。本次航程分为三个航段，中途停靠托雷斯海峡的凯恩斯港与霍恩岛。 地球物理测绘作业依托“Falkor号”科考调查船搭载的康斯伯格EM302与EM710多波束系统开展，通常以双条带测绘模式（Dual Swath mode）运行。当水深超过约1200米时，将关闭EM710系统。两套多波束系统同时采集了反向散射数据与水柱数据。 本V1版本数据集包含2份分辨率为64米、32位的GeoTIFF格式文件，对应FK200930调查区域，数据由仅基于EM302系统处理得到的水深测绘数据生成。本数据集不得用于导航用途。本数据集经澳大利亚地球科学局（Geoscience Australia）首席执行官批准发布。