摘要:
利用seabat8101多波束系统对扬子浅滩东南海底地形进行了高精度探测.发现海底呈明显近乎平行排列的条带状起伏,脊谷相间,沙脊大部分呈NW-SE向排列,发育在45~50 m水深范围之内,沙脊横剖面不对称,大部分沙脊西南侧坡度大、东北坡缓.沙脊规模略有差异,沙脊宽度约0.6~9.8 km,沙脊之间间距可达8.9~22.4 km,高度约1.8~13.3 m,研究区内最长可达53 km.部分脊槽过渡区域发育成片链状海底沙波,沙波大致呈NE-SW走向,波高约0.3~1 m,波长1 km左右.研究区中西部有海底礁石孤立地突兀于相对平坦的海底之上,暂定名为扬礁,最浅水深35.9 m,位于30°59′7.4″~31°N,124°36′48.7″~124°37′40″E.扬子浅滩东南海域沙脊是介于活动沙脊和衰亡沙脊之间的准活动沙脊.该研究将为我国海洋开发和海洋经济发展、海洋行政管理以及海洋安全保障提供服务.%The southeast Yangtze Shoal on the continental shelf in the East Sea is characterized by tidal sand ridges, and this study measures its three-dimensional morphology using the Seabat8101 sounding system. Tidal sand ridges are arranged in a NW-SE parallel pattern and developed from a depth of 45 m to 50 m. Cross profiles of sand ridges are asymmetrical; the gradient of the south side of most ridges varies between 0.043° and 0.134°, which is steeper than that of the north side. The scales of the sand ridges differ; heights and widths vary from 1.8 m to 13.3 m and 0.6–9.8 km, respectively, and the space between adjacent ridges varies from 8.9–22.4 km. Developed in the flank of sand ridge, several patches of sand waves have NE-SW strikes, where the sand wave height varies from 0.3–1 m with a wave length of about 1 km. An isolated submerged reef stand out in the west of the study area: temporarily named the Yangjiao Reef, it is located between 30°59′7.4″–31°00′00″N, and 124°36′48.7″–124°37′40″E and lies at a depth of 35.9 m at its most shallow part. These sand ridges are classified as qua-active sand ridges and are thus between the types of active and declined sand ridges.