中国近海海底地形特征及剖面类型分析  

Topography characteristics and profile type of China offshore submarine

作　　者：曹超[1,2] 蔡锋[1] 郑勇玲[1] 吴承强[1] 卢惠泉[1] 鲍晶晶[1] 许艳[1] 

机构地区：[1]国家海洋局第三海洋研究所,福建厦门361005 [2]厦门大学环境与生态学院,福建厦门361005

出　　处：《中南大学学报（自然科学版）》2014年第2期483-494,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(41276058);国家海洋局"908"专项(908-ZC-I-07);国家海洋局公益性科研项目(201105001;2012418004)

摘　　要：基于国家海洋局“908”专项的最新海底地形资料，分析中国近海海底地形特征及其影响因素。中国近岸海底地形继承了陆地地形西北向东南倾斜的趋势，海底地形坡降为0．2‰～1．6‰，平均坡降约0．8‰，等深线基本平行于海岸展布，河口区呈舌状向海展布。海底地形受构造控制作用明显，呈两窿两坳的南、北分带特征，并在不同沉积环境和复杂水动力条件下塑造出沉降盆地型、挤压隆起型、沉积改造型和过渡型等4种类型。沉降盆地型和挤压隆起型地形起伏小，沉积物以细粒为主，水流方向单一，易发育海湾堆积平原和水下堆积岸坡等堆积型地貌，同属构造成因的地形；沉积改造型地形起伏较大，沉积物以粗粒为主，多在陆源补给丰富的河口和潮流辐聚区发育大型潮流沙脊，全新统沉积层巨厚，受潮流、径流、海流的后期改造作用明显；过渡型地形陡缓不均，沉积物颗粒不均匀混合，近岸发育阶地状陡坎，远岸发育陆架平原等侵蚀一堆积型地貌，为断陷地块不完全发育和多期次海侵共同作用的结果。Abstraet： Based on the latest submarine topography data of ＂908＂ special project of the State Oceanic Administration, topographical characteristics and its influencing factors of China offshore submarine were analyzed. China offshore submarine topography inherits land topographical trend from northwest to southeast. The submarine topographical gradient is from 0.2%0 to 1.6%o and the average gradient was about 0.8%0. The depth contour is substantially parallel to the coast spreading and is tongue to sea spreading at estuary area. The submarine topography is dominated by the geological structure, which shows the typical characteristics about two uplifts and two subsides form north to south. Four types have been with the influence of different sedimentary environments and complex hydrodynamic shape： sedimentary basin, squeeze uplift, deposit reformation and transition types. On the sedimentary basin and squeeze uplift area, topographical undulate is small, sediments is fine, flowing current is single direction and easily develops the gulf accumulation plains and underwater accumulation slope. They belong to the same tectonic origin topography. On the deposit reformation area, topographical undulate is large, sediments are coarse, develop tidal sand ridges at terrigenous supply estuary and convergence trend zone, Holocene sediments are thick, and obviously transformed by tidal, runoff and currents. On the transition area, change of topographical undulate and sediment particles mixed are uneven and develop terraces like scarp inshore and shelf plains erosion-accumulation landforms offshore. That is the common result of incompletely developed plots rift and transgression of many times. Key words： China offshore submarine; topography characteristics; profile type; influencing factors

关 键 词：中国近海海底 地形特征 剖面类型 影响因素 

分 类 号：P736.5[天文地球—海洋地质]