三沙永乐龙洞悬浮体垂直分布特征及其影响因素  

Vertical distribution characteristics and influencing factors of suspended matter in the Sansha Yongle Blue Hole,South China Sea

作　　者：闫文文 谷东起 杜军 李平 明洁 于晓晓 李建坤 王恩康 徐国强 Yan Wenwen;Gu Dongqi;Du Jun;Li Ping;Ming Jie;Yu Xiaoxiao;Li Jiankun;Wang Enkang;Xu Guoqiang(First Institute of Oceanography,Ministry of Natural Resources,Qingdao 266061,China;School of Foreign Languages,Qingdao University,Qingdao 266071,China;Key Laboratory of Coast and Island Development,Ministry of Education,Nanjing University,Nanjing 210023,China)

机构地区：[1]自然资源部第一海洋研究所,山东青岛266061 [2]青岛大学外语学院,山东青岛266071 [3]南京大学海岸与海岛开发教育部重点实验室,江苏南京210023

出　　处：《海洋学报》2019年第11期117-126,共10页

基　　金：中央级公益性科研院所基本科研业务费专项资金（2014G16）;国家重点研发计划—海水淡化取水口空间位置选划和优化布局（2018YFC040800101）;科技基础资源调查专项—中沙群岛及邻近海域海洋水动力环境调查（2018FY100102）

摘　　要：为研究中国唯一已知、全球最深海洋蓝洞的形成、发育和演化机制,应用LISST-100X现场激光粒度仪、CTD温盐仪等搭载工作级水下机器人,于2017年5月在三沙永乐龙洞进行了悬浮体、温盐剖面测量,获得了全洞深的悬浮体体积浓度、温盐和溶解氧等数据,并进行了悬浮体垂向分布特征研究。研究结果表明,洞内90 m以下水体为无氧环境,悬浮体浓度呈现5个变化旋回,温度、盐度均存在3个跃层,并且它们之间有着较好的对应关系。龙洞内水体表层悬浮体总浓度约为20μL/L,悬浮体平均浓度值为5.93μL/L。悬浮体旋回层Ⅰ位于5 m以浅水层;旋回层Ⅱ位于10~43 m之间,与第一个温盐跃层(深度10~20 m)部分对应;旋回层Ⅲ位于70~110 m之间,与第二个温盐跃层(深度70~110 m)完全对应;旋回层Ⅳ位于130~150 m之间,与第三个温盐跃层(深度130~150 m)完全对应;旋回层Ⅴ位于260 m以深至洞底300 m。龙洞表层悬浮体浓度较高,主要是受到洞外周边珊瑚礁松散沉积物输入的影响。洞内悬浮体垂直分布特征主要受到水动力、洞体形态、温盐跃层、溶解氧含量以及浮游生物等的控制和影响。In order to study the formation,development and evolutionary mechanism of the only known marine blue hole in China,also the deepest one in the world,we used the LISST-100X and CTD carried by remote operated vehicle for the measurement of suspended matter and the profile of temperature and salinity in the Sansha Yongle Blue Hole in May 2017.We acquired the data of the volume concentration of suspended matter,temperature,salinity and dissolved oxygen,then we conducted the study of the vertical distribution characteristics of suspended matter.The results indicate that the water below 90 m of the cave is anaerobic and the concentration of suspended matter presents 5 cycle changes.The results also indicate that there are three thermoclines and three haloclines in the Sansha Yongle Blue Hole,and there is a good correspondence between them.The total concentration of suspended matter in the surface water is about 20μL/L,and the average concentration of suspended matter is 5.93μL/L.CyclothemⅠlies at 5 m in shallow water layer;cyclothemⅡlies between 10 m and 43 m below the water surface,partially corresponding to the first thermocline and halocline water depth(10–20 m);cyclothemⅢlies between 70 meters to 110 m at depth,completely corresponding to the second thermocline and halocline(water depth 70–110 m);cyclothemⅣlies between 130 m to 150 m,completely corresponding to the third thermocline and halocline(water depth 130–150 m);cyclothemⅤlies in 260 m and then deep to 300 m.The suspended matter concentration on the surface is high,as is mainly affected by the sediment input from the surrounding coral reefs.The vertical distribution characteristics of suspended matter in the Sansha Yongle Blue Hole is mainly controlled and affected by hydrodynamic force,cave morphology,thermocline,halocline,dissolved oxygen content and plankton.

关 键 词：三沙永乐龙洞 悬浮体 温跃层 盐跃层 垂直分布 影响因素 

分 类 号：P736.21[天文地球—海洋地质]