This paper reports on results of the investigation of marine biofouling on offshore structures east of Hainan Island in the northern South China Sea. Two buoy investigation stations were deployed in Qiongdong (W1, 68 ...This paper reports on results of the investigation of marine biofouling on offshore structures east of Hainan Island in the northern South China Sea. Two buoy investigation stations were deployed in Qiongdong (W1, 68 n miles offshore) and southern Qiongdong (J2, 23 n miles offshore) waters, respectively. At both sites, water depths were more than 100 meters. Test panels on iron frames were placed at 1, 10, 25, 50 and 100 m below the seawater surface, and exposed for 8 months from October 1989 to June 1990. The results indicated that hydroids, gooseneck barnacles and oysters were the most important fouling species in these offshore areas. Acorn barnacles were mainly found at Station J2. The maximum fouling accumulations were observed in near surface waters. Substantial reduction of biomass and species diversity occurred with increasing depth and distance from shore. Sources of fouling organisms and influences of environmental factors on the species distributions are discussed in this paper.展开更多
琼北地区铺前−清澜断裂是一条关系到1605年琼山7½级大地震发震构造判断的重要断裂。为准确厘定该断裂的最新活动特征,针对琼北地区第四纪玄武岩盖层和巨厚海相砂沉积等地质条件,采用大吨位震源的浅层人工地震勘探和小间距钻孔联合...琼北地区铺前−清澜断裂是一条关系到1605年琼山7½级大地震发震构造判断的重要断裂。为准确厘定该断裂的最新活动特征,针对琼北地区第四纪玄武岩盖层和巨厚海相砂沉积等地质条件,采用大吨位震源的浅层人工地震勘探和小间距钻孔联合地质剖面探测相结合的方法,分别在海口江东三江镇岐山头村和东寨村展开探测。结果表明:(1)铺前−清澜断裂断错了多个标志地层,最浅断错至全新统烟墩组淤泥层,上断点埋深10 m左右,钻探所揭示的断层面明显具有走滑兼具逆冲性质,是一条具有一定宽度、多分支、多期次活动的大规模断裂带;(2)钻孔联合地质剖面所揭示的地层深度范围内,被断错地层的位移量随着深度增加而加大,铺前−清澜断裂自8346~7153 a cal BP以来有过活动,全新世累计垂直位移量4~5 m,垂直位移速率为0.53~0.63 mm/a,推断其为1605年琼山大地震的发震断裂。本研究取得的铺前−清澜断裂全新世活动的新证据,为国土空间规划和区域地震危险性评价提供了科学依据。展开更多
文摘This paper reports on results of the investigation of marine biofouling on offshore structures east of Hainan Island in the northern South China Sea. Two buoy investigation stations were deployed in Qiongdong (W1, 68 n miles offshore) and southern Qiongdong (J2, 23 n miles offshore) waters, respectively. At both sites, water depths were more than 100 meters. Test panels on iron frames were placed at 1, 10, 25, 50 and 100 m below the seawater surface, and exposed for 8 months from October 1989 to June 1990. The results indicated that hydroids, gooseneck barnacles and oysters were the most important fouling species in these offshore areas. Acorn barnacles were mainly found at Station J2. The maximum fouling accumulations were observed in near surface waters. Substantial reduction of biomass and species diversity occurred with increasing depth and distance from shore. Sources of fouling organisms and influences of environmental factors on the species distributions are discussed in this paper.
文摘琼北地区铺前−清澜断裂是一条关系到1605年琼山7½级大地震发震构造判断的重要断裂。为准确厘定该断裂的最新活动特征,针对琼北地区第四纪玄武岩盖层和巨厚海相砂沉积等地质条件,采用大吨位震源的浅层人工地震勘探和小间距钻孔联合地质剖面探测相结合的方法,分别在海口江东三江镇岐山头村和东寨村展开探测。结果表明:(1)铺前−清澜断裂断错了多个标志地层,最浅断错至全新统烟墩组淤泥层,上断点埋深10 m左右,钻探所揭示的断层面明显具有走滑兼具逆冲性质,是一条具有一定宽度、多分支、多期次活动的大规模断裂带;(2)钻孔联合地质剖面所揭示的地层深度范围内,被断错地层的位移量随着深度增加而加大,铺前−清澜断裂自8346~7153 a cal BP以来有过活动,全新世累计垂直位移量4~5 m,垂直位移速率为0.53~0.63 mm/a,推断其为1605年琼山大地震的发震断裂。本研究取得的铺前−清澜断裂全新世活动的新证据,为国土空间规划和区域地震危险性评价提供了科学依据。
