Swath multibeam bathymetry surveys for Congo Submarine Canyon and Channel collected in 2019 and 2020, and changes in seabed elevation.
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Swath multibeam surveys of seafloor bathymetry data were collected in two areas: Upper Congo Canyon in Angolan waters, and deeper-water channel in International waters between September 2019 and October 2020 using a Kongsberg EM122 (1 degree x 1 degree) system operating at 12 kHz. Higher resolution data was generated by setting the swath width to the narrowest setting (45 degrees from the nadir), and having large overlaps between adjacent swaths. Sound velocity profiles (SVPs) were taken through the water column at the start of most surveys, and a second SVP was performed halfway through some longer surveys. Multibeam sonar bathymetric data were processed in CARIS HIPS and SIPS and corrected for the ship's motion and for differences in sound velocity in the water column (using SVP data), before being gridded with a horizontal grid cell dimension of 5m (upper canyon in Angolan waters) or 15m (deep-water channel within international waters). Data were cleaned manually for obvious outliers in CARIS. A bathymetric difference map was then produced by subtracting October 2020 bathymetric data from September 2019 bathymetric data. This was done to document patterns of seabed erosion and deposition caused by turbidity currents between 2019 and 2020. Data were collected under NERC Grant references NE/R001952/1 and NE/R001960/1 lead by Professor Peter Talling at Durham University.
研究团队于2019年9月至2020年10月间，在两处海域采集了海底测深条带多波束数据：分别为安哥拉海域的刚果峡谷上段（Upper Congo Canyon），以及国际公海的深水水道，采集所用设备为工作频率12 kHz的Kongsberg EM122（1°×1°）系统。 高分辨率数据通过将条带宽度调至最窄档位（距星下点45°），并加大相邻条带间的重叠覆盖率生成。 多数调查作业启动时，均通过水体剖面采集声速剖面（Sound Velocity Profiles，SVPs）；部分长周期调查还会在作业中途开展第二次SVP测量。 多波束测深声呐数据先在CARIS HIPS与SIPS软件中完成处理，针对船舶运动及水体声速差异（采用SVP数据）校正后，进行网格化处理：安哥拉海域刚果峡谷上段的网格水平单元尺寸为5米，国际公海深水水道的网格水平单元尺寸为15米。 研究人员在CARIS软件中手动剔除了数据中的明显异常值。 随后通过将2019年9月的测深数据与2020年10月的测深数据相减，生成测深差异图，用以记录2019至2020年间由浊流（turbidity currents）引发的海底侵蚀与沉积格局。 本数据集由英国杜伦大学（Durham University）彼得·托林（Peter Talling）教授主持，依托英国自然环境研究委员会（Natural Environment Research Council，NERC）资助项目编号NE/R001952/1与NE/R001960/1完成数据采集。
