摘要
基于高精度多波束、单波束、侧扫声呐等资料研究发现,福建近岸闽江口和三沙湾口外海域分别发育一处海底沙波群。本文详细分析了海底沙波地貌发育特征,根据沙波发育形态及沙脊线走向将其分为挠曲型沙波、直线型沙波和过渡型沙波3类。调查区2处沙波群均呈迎潮面坡度缓而背潮面陡的特征,沙波末端均存在分枝并伴随着一定程度的弯曲变形。沉积物质来源和水文动力环境是控制海底沙波群发育的两个主要因素,研究区近岸基岩侵蚀物质、河流沉积物质和洋流输运物质来源减少打破了维持沙波动态平衡的物质供应,底流冲刷提供了海底泥沙的起动条件。结合沙波纹、残留沙丘及海底沙波的发育特征,本文认为沙波存在一定的活动性,具有向坡陡一侧不断迁移的规律。最后,通过对沙波活动性成因和演化规律进行分析,并详细探讨了海底沙波的存在对海洋工程应用的影响,提出了相应的防范措施,为近岸海底工程建设及灾害预防提供了一定的借鉴意义。
Based on high-precision multi-beam,single-beam,side-scan sonar and other data,the authors found two submarine sand wave groups in the offshore areas of Fujian's Minjiang estuary and Sanshawan estuary,respectively.In this paper,the geomorphic characteristics of the development of the submarine sand wave were analyzed in detail.According to the shape of the development of the sand wave and the trend of the sand ridge line,it can be divided into three types:flexural sand wave,linear sand wave and transitional sand wave.Both sand wave groups show a slower slope on the tide and a steeper tide,which is characterized by branching at the end of the sand wave and is accompanied by a certain degree of bending deformation.Sources of sedimentary materials and hydrodynamic environment are two main factors that control the development of sand wave groups on the sea floor.The reduction of sources of near-shore bedrock erosion materials,river sediment materials and ocean current transport materials in the study area breaks the material supply that maintains the dynamic balance of sand waves.Underflow scouring provides the starting conditions for seabed sediments.Combined with the development characteristics of sand ripples,residual dunes and seabed sand waves,the authors hold that sand waves have certain activities and have a law of continuous migration to the steep side of the slope.Finally,through the analysis of the causes and evolution rules of sand wave activity,the authors discussed the influence of the existence of sand wave on the application of marine engineering in detail,and put forward the corresponding preventive measures,which provides a certain reference for the construction of offshore seabed engineering and disaster prevention.
作者
伊善堂
吴承强
林纪江
胡小三
罗伟东
YI Shantang;WU Chengqiang;LIN Jijiang;HU Xiaosan;LUO Weidong(Guangzhou Marine Geological Survey,CGS,Guangzhou 510760,Guangdong,China;Key Laboratory of Marine Mineral Resources,Ministry of Natural Resources,Guangzhou 510760,Guangdong,China;Third Institute of Oceanography,Ministry of Natural Resources,Xiamen 361005,Fujian,China;South China Sea Information Center of State Oceanic Administration,Guangzhou 510310,Guangdong,China)
出处
《中国地质》
CAS
CSCD
北大核心
2020年第5期1554-1566,共13页
Geology in China
基金
自然资源部海底矿产资源重点实验室基金(KLMMR-2018-A-08)
中国地质调查局项目(DD20160138,DD20190209,DD20190627,DD20191002)联合资助。
关键词
近岸海域
沙波群
地貌特征
控制因素
起动流速
海洋地质调查工程
闽江口
三沙湾口
福建
offshore waters
sand wave group
geomorphological characteristics
controlling factor
starting velocity
Marine geological survey engineering
Minjiang estuary
Sansha bay estuary
Fujian
