Bathymetric data from the Northern Red Sea

If you use these data, please refer to Ribot M., et al. (2024), Vertical deformation along a strike-slip plate boundary: the uplifted marine terraces of the Gulf of Aqaba and Tiran Island, at the southern end of the Dead Sea Fault, Tectonics, in press. A high-resolution bathymetric survey of the northern Red Sea, near the Strait of Tiran and Tiran Island was conducted on board the R/V Thuwal from September 3rd to September 10th, 2019. We used a Kongsberg EM710-MK2 multibeam echo sounder (operating in the 70-100 kHz range) calibrated with CTD (Conductivity, Temperature, Depth) profiles. In order to maximize the range capability and to reduce interference from multiple returns we used a transmit fan which sequentially divides the signal into three sectors with distinct transmit frequencies and waveforms. We limited the system to a swath of 2000 m (i.e. 1000 m swath on each side of the beamer) in order to ensure appropriate beam density as to grid the data in a 10 m wide pixel raster across the track. Similarly, the survey speed was kept at 5-6 kn (~10 km/h) to limit the spacing between successive survey points and to ensure that the maximum pixel width is 10 m along the track as well. Survey lines were acquired every ~1000 m in deep water and 800 m near the shore, to ensure a double coverage of each point in opposite directions. The results were imported into the commercial SiS multibeam software and used to correct the incoming multibeam data. Then, the bathymetric data were automatically screened for obvious outliers and, additionally, we manually identified and removed remaining spurious data points. From this dataset, we built a Digital Elevation Model (DEM) of the bathymetry by averaging raw data values to a 10 m horizontal grid. The vertical resolution of the DEM is controlled by the pulse duration of the acoustic signal. The vertical resolution (R) can be calculated following R = v⋅d/2 with v the wave propagation velocity in water and d the duration of the signal. During the data acquisition, we tuned the pulse duration at 2 ms, and calibrated the wave propagation velocity with the CTD casts with values ranging between 1535 and 1558 m/s. Thus, it implies that the vertical resolution is 1.5 m. If you use these data, please refer to Ribot M., et al. (2024), Vertical deformation along a strike-slip plate boundary: the uplifted marine terraces of the Gulf of Aqaba and Tiran Island, at the southern end of the Dead Sea Fault, Tectonics, in press.若使用本数据集，请引用Ribot M.等人（2024）发表于《Tectonics》（即将刊出）的论文：《沿走滑板块边界的垂直形变：死海断裂南段亚喀巴湾与蒂朗岛的抬升海蚀阶地》。 2019年9月3日至9月10日，研究团队依托“Thuwal”号科考船（R/V Thuwal），在蒂朗海峡与蒂朗岛附近的红海北部海域开展了高分辨率水深测量。本次测量使用了Kongsberg EM710-MK2型多波束测深仪（multibeam echo sounder，工作频段70~100 kHz），并通过CTD（电导率、温度、深度，Conductivity, Temperature, Depth）剖面数据对设备进行了校准。为最大化测程并降低多回波干扰，本次测量采用了发射扇形波束（transmit fan）技术，将信号依次划分为三个具有不同发射频率与波形的扇区。我们将系统测幅限制为2000 m（即测深仪两侧各1000 m），以确保合适的波束密度，从而将沿测线的数据网格化为10 m宽度的像素栅格（pixel raster）。同时，将测量航速维持在5~6节（约10 km/h），以缩小相邻测量点的间距，确保沿测线方向的最大像素宽度同样为10 m。深水区域的测线间距设置为约1000 m，近岸区域则为800 m，以确保每个测点均可被正反两个方向的测线双向覆盖。 测量数据导入商用SiS多波束软件后，首先对原始多波束数据进行了校正处理。随后，研究团队自动筛选了水深数据中的明显异常值，并人工识别并剔除了剩余的虚假数据点。 基于本数据集，研究团队通过将原始数据平均至10 m水平网格，构建了水深数字高程模型（Digital Elevation Model, DEM）。该DEM的垂直分辨率由声信号的脉冲时长决定。垂直分辨率（R）可通过公式R = v·d/2计算，其中v为声波在水中的传播速度，d为信号脉冲时长。数据采集阶段，研究团队将脉冲时长设置为2 ms，并通过CTD剖面测量校准了声波传播速度，校准值介于1535~1558 m/s之间。由此可得，本DEM的垂直分辨率为1.5 m。 若使用本数据集，请引用Ribot M.等人（2024）发表于《Tectonics》（即将刊出）的论文：《沿走滑板块边界的垂直形变：死海断裂南段亚喀巴湾与蒂朗岛的抬升海蚀阶地》。