Mar. Res. 2021/12
Vol.1. Iss.1 :1-23
Characteristics of Sand Waves of the Changyun Sand Ridge and Taiwan Shoal in the Taiwan Strait

Liwen Chen1*, Yi-Wei Lu2, Wei-Chung Han3 and Sheng-Chung Lo2
1National Academy of Marine Research, Ocean Affairs Council, Taiwan
2Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Taiwan
3Exploration and Development Research Institute, CPC Corporation, Taiwan

Abstract: Seabed topography reveals fundamental information of the earth system at multiple scales. Geomorphologic studies provide insights into the interaction between the hydrosphere and solid earth. We reviewed previous studies of the dynamic seabed environment in the Taiwan Strait and classified the sand waves of the Changyun Sand Ridge and Taiwan Shoal by compiling and analyzing the crest-line distribution and sand wave geometries. We identified five types of sand waves coexisting in the western Changyun Ridge, including long bed trochoidal (LT-type), symmetrical (S-type), trochoidal (T-type), sinusoidal (Sin-type) sand waves, and mega-ripples (Mr-type). Their heights (amplitudes) and wavelengths range from 4.5 to 37 m and 244 to 2,115 m, respectively. In Taiwan Shoal, trochoidal sand waves almost cover the entire area, while the sinusoidal and bimodal sand waves spread in the middle and western portions; the wave heights and wavelengths range from 0.3 to 10 meters and 5 to 1,700 meters, respectively. However, further time-dependent bathymetric and oceanographic investigations are required to simulate the long-term behavior of potential bedform variation along with extreme events. Monitoring the migration of sand waves will also contribute to understanding seabed stability and thus offshore engineering designs in the Taiwan Strait.

Keywords:  seabed topography, geomorphology, Taiwan Strait, sand waves.

*Corresponding author; e-mail: liwen@namr.gov.tw
© 2021  Marine Research , ISSN 2709-6629 

161 Views 68 Downloads