Submarine Geomorphological Features and Their Origins Analyzed from Multibeam Bathymetry Data in the South China Sea

Xiaolin Ou; Junjiang Zhu; Sanzhong Li; Yonggang Jia; Zhongjia Jia; Shengsheng Zhang; Shaoyu Zhang; Ruixue Chen; Xingquan Chen; Dong Ding; Huilin Xing; Yanhui Suo; Pengcheng Wang; Yongjiang Liu

doi:10.3390/jmse9121419

Journal of Marine Science and Engineering (Dec 2021)

Submarine Geomorphological Features and Their Origins Analyzed from Multibeam Bathymetry Data in the South China Sea

Xiaolin Ou,
Junjiang Zhu,
Sanzhong Li,
Yonggang Jia,
Zhongjia Jia,
Shengsheng Zhang,
Shaoyu Zhang,
Ruixue Chen,
Xingquan Chen,
Dong Ding,
Huilin Xing,
Yanhui Suo,
Pengcheng Wang,
Yongjiang Liu

Affiliations

Xiaolin Ou: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Junjiang Zhu: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Sanzhong Li: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Yonggang Jia: Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, China
Zhongjia Jia: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Shengsheng Zhang: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Shaoyu Zhang: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Ruixue Chen: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Xingquan Chen: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Dong Ding: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Huilin Xing: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Yanhui Suo: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Pengcheng Wang: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
Yongjiang Liu: Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, College of Marine Geosciences, Ocean University of China, Qingdao 266100, China

DOI: https://doi.org/10.3390/jmse9121419
Journal volume & issue: Vol. 9, no. 12
p. 1419

Abstract

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We processed the raw multi-beam bathymetry data acquired in the central and northeastern part of the South China Sea by eliminating noise and abnormal water depth values caused by environmental factors, and a high resolution bathymetric map with a 20-m grid interval was constructed. Various scales of seafloor geomorphological features were identified from the data, including an image of Shenhu canyon, which is located in the northern continental margin of the South China Sea; submarine reticular dunes in the north of the Dongsha atoll; submarine parallel dunes in the northeast of the Dongsha atoll; and several seamounts in the southwest sub-basin and in the east sub-basin. In the processing step, various anomalies in the multi-beam bathymetry data were corrected. The optimal swath filtering and surface filtering methods were chosen for different scales of seafloor topography in order to restore the true geomorphological features. For the large-scale features with abrupt elevation changes, such as seamounts (heights of ~111–778 m) and submarine canyons (incision height of ~90–230 m), we applied swath filtering to remove noise from the full water depth range of the data, and then surface filtering to remove small noises in the local areas. For the reticular dunes and parallel dunes (heights of ~2–32 m), we applied only surface filtering to refine the data. Based on the geometries of the geomorphological features with different scales, the marine hydrodynamic conditions, and the regional structure in the local areas, we propose that the Shenhu submarine canyon was formed by turbidity current erosion during the Sag subsidence and the sediment collapse. The submarine reticular dunes in the north of the Dongsha atoll were built by the multi-direction dominant currents caused by the previously recognised internal solitary waves around the Dongsha atoll. The submarine parallel dunes in the northeast of the Dongsha atoll were built by the repeated washing of sediments with the influence of the tidal currents and internal solitary waves. The conical, linear and irregular seamounts identified from the bathymetry data were formed during the spreading of the southwest sub-basin and the east sub-basin. The identified seamounts in the multi-beam bathymetry data are correlated to deep magmatic activities, the Zhongnan transform fault and the NE-trending faults.

Published in Journal of Marine Science and Engineering

ISSN: 2077-1312 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Naval Science: Naval architecture. Shipbuilding. Marine engineering; Geography. Anthropology. Recreation: Oceanography
Website: http://www.mdpi.com/journal/jmse

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