In situ acoustic properties of fine-grained sediments on the northern continental slope of the South China Sea. (15th December 2020)

• Record Type: Journal Article
• Authors: Li, Guanbao; Wang, Jingqiang; Liu, Baohua; Meng, Xiangmei; Kan, Guangming; Han, Guozhong; Hua, Qingfeng; Pei, Yanliang; Sun, Lei
• Is Part Of: Ocean engineering. Volume 218(2020)
• Publication Date: 2020-12-15
• Subjects: Sound speed -- Attenuation -- Fine-grained sediment -- In situ measurement -- Continental slope -- South China Sea; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2020.108244
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Measuring the in situ acoustic properties of the sediments on continental slopes is essential not only for model construction but also for sedimentary environment and slope stability assessments. To acquire the acoustic properties of the fine-grained sediments on the northern slope of the South China Sea (SCS), this study conducted an experiment using the deep-water hydraulic-driven in situ sediment acoustic measurement system (HISAMS). There were four experimental stations in this study, one on the upper slope and the other three on the lower slope, the sound speed and attenuation coefficient values were obtained at different depths within 1.4 m below the seabed. The results showed extraordinarily low and vertically uniform acoustic properties in the fine-grained sediment on the SCS northern slope. Combined with other in situ data previously reported near the study region, the spatial distribution characteristics of the sediment acoustic properties were analyzed, and the results revealed a downslope variation trend and an along-slope uniformity. The distribution pattern of the sediment sound speed was related to the water depth, and the sedimentary environment might be the key constraint on the vertical variation feature of the sediment acoustic properties on the continental slope. Highlights: The acoustic properties in fine grained sediments were in-situ measured on the northern slope of South China Sea. The sound speeds have a vertically uniform characteristics at different depth within 1.4m below the seabed. The acoustic properties distribution trends are related to the water depth and the sedimentary environment.