摘要
2011—2015年对东沙和神狐水合物钻探区进行了连续5年7个航次的海上调查工作,获取了大量研究区海水水文、水化学及溶解甲烷含量数据,为天然气水合物勘查与试采环境评价提供了良好的基础数据及采前环境基线。调查期间,研究区海水甲烷浓度范围为0~31.4nmol·L^(-1),平均浓度为6.7nmol·L^(-1),高于全球平均海水甲烷浓度,表明南海海水甲烷浓度本底值高于全球平均水平;研究区海水溶解甲烷浓度及其分布特征不受区域海水水文特征、海水化学特征及季节等因素影响,且表层海水-大气甲烷交换并非单一的汇或者源的关系,而是根据时间的不同,海水-大气甲烷交换存在汇源转换;综合调查结果表明,研究区甲烷渗漏对海水、大气甲烷含量没有明显影响,且水合物钻探对区域环境没有明显的影响。
From the seven voyages of environmental impact survey in the Shenhu and Dongsha gas hydrate drilling areas from 2011 to 2015,abundant data relating to marine hydrology,marine chemistry,and dissolved methane concentration in the drilling areas were collected to evaluate the environmental impacts of gas hydrate exploration and exploitation.During 2013 to 2015,the dissolved methane concentration in the sea water in the drilling areas ranged between 0to 31.4 nmol·L^-1 with an average of 6.7 nmol·L^-1.This average concentration is higher than that of the global mean value in sea water,indicating that the baseline of dissolved methane in the gas hydrate drilling areas of the South China Sea is higher than the global average.The concentration and distribution of methane in sea water of the study areas is not affected by changes in hydrological and sea water chemistry parameters. Methane exchange between sea surface water and atmosphere varied in different survey cruises.Survey results show that there is no significant methane seepage in the study areas,and the gas hydrate drilling project has no influence on the dissolved methane concentration in sea water of the drilling areas.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2017年第4期89-101,共13页
Earth Science Frontiers
基金
中国地质调查局项目(GZH201100311)
国土资源部海底矿产资源重点实验室开放基金项目(KLMMR-2013-A-35)
国家自然科学基金项目(91228201)
关键词
海水甲烷浓度
分布特征
影响因素
环境影响
水合物钻探区
南海
dissolved methane in seawater
distribution characteristics
influential factors
environmental influence
gas hydrate drilling area
South China Sea
