摘要
海底冷泉是指来自海底沉积地层(或更深)的气体以喷涌或渗漏的方式注入海洋中的一种海洋地质现象,它普遍发育于主动大陆边缘和被动大陆边缘。海底冷泉研究在天然气水合物、全球气候变化、极端生物群落等研究方面都具有重要意义。利用实测的海上资料,通过分析水体声学剖面上的冷泉气柱、旁扫声纳图像上的亮斑异常以及柱状沉积物样品中天然气水合物等的对应关系,指出旁扫声纳图像上出现的亮斑异常是海底冷泉喷逸的指示。海底冷泉逸出的大量气泡遮蔽海底,从而形成一个强波阻抗界面,这个强波阻抗界面在旁扫声纳图像上形成亮斑异常。通过亮斑异常,可以判定海底冷泉的存在。旁扫声纳可以成为海底冷泉探测的有力方法。
Cold seeps have been widely encounted on both active and passive continental margins since 1960s.Due to its close relationship with gas hydrates formation,oil and gas deposition,global climate changing and non-photosynthesis life on deep water seafloor,cold seep study has attracted more attention of both science and industry in recent years.Based on cruise data,consistence among bubble plume in water column recorded on acoustic profile,bright spot anomaly happened on side scan sonar sonogram,and gas hydrate sample recovered from the gravity core at the same site had been analyzed.The paper believed that at the area of cold seep,gas bubbles from venting site shaded the seafloor forming a strong acoustic impedance interface between the bubble covered seafloor and the water column.This strong acoustic impedance interface form a bright spot anomaly on the side scan sonar sonogram.So that the bright spot anomaly on the side scan sonar sonogram is a right indicator for the existence of cold seep on the seafloor.For the detection and measurement of cold seep in a new area,the side scan sonar system will be the right method.
出处
《现代地质》
CAS
CSCD
北大核心
2010年第3期474-480,共7页
Geoscience
基金
中国科学院创新工程重要方向项目(KZCX2-YW-211-01)
国家自然科学基金项目(40776032)
科技部“973”项目(2007CB411702)
关键词
海底冷泉
旁扫声纳
图像识别
气泡群
cold seepage
side scan sonar
characteristics
bubble plume
