三沙永乐龙洞：修订间差异

'''三沙永乐龙洞'''，又称'''三沙市蓝洞'''或'''永乐蓝洞'''，位于中国[[西沙群岛]][[永乐环礁]][[晋卿岛]]与[[石屿]]的礁盘中，是一个海洋[[蓝洞]]，洞口直径为130米，洞底直径约36米，深度达{{convert|300.89|m|ft}}，是目前已知世界上最深的[[蓝洞|海洋蓝洞]]。永乐龙洞基本为垂直洞穴，洞内水体无明显流动，尚未观测到洞内与外海联通<ref name=":0">{{Cite journal |last1=Li|first1=Tiegang |last2=Feng|first2=Aiping |last3=Liu|first3=Yanxiong |last4=Li|first4=Zhenhong |last5=Guo|first5=Kai |last6=Jiang|first6=Wenzheng |last7=Du|first7=Jun |last8=Tian|first8=Ziwen |last9=Xu|first9=Wenxue |last10=Liu|first10=Yang| last11=Wang|first11=Yanru |date=2018-11-20 |title=Three-dimensional (3D) morphology of Sansha Yongle Blue Hole in the South China Sea revealed by underwater remotely operated vehicle|journal=Scientific Reports|language=en|volume=8|issue=1|page=17122|doi=10.1038/s41598-018-35220-x|pmid=30459420|pmc=6244355|bibcode=2018NatSR...817122L|issn=2045-2322 |url=https://rdcu.be/b6ySW}}</ref>。永乐龙洞内深度100公尺一直到洞底部分属无氧空间<ref name=":2">{{Cite journal |last1=Xie|first1=Linping|last2=Wang|first2=Baodong |last3=Pu|first3=Xinming|last4=Xin|first4=Ming|last5=He|first5=Peiqing |last6=Li|first6=Chengxuan|last7=Wei|first7=Qinsheng|last8=Zhang|first8=Xuelei|last9=Li|first9=Tiegang|date=2019-02-01|title=Hydrochemical properties and chemocline of the Sansha Yongle Blue Hole in the South China Sea|url=http://www.sciencedirect.com/science/article/pii/S0048969718333047|journal=Science of the Total Environment|language=en|volume=649|pages=1281–1292|doi=10.1016/j.scitotenv.2018.08.333|pmid=30308898|bibcode=2019ScTEn.649.1281X|issn=0048-9697}}</ref>。