东海海底地形分区特征和成因研究  

Study on Zoned Characteristics and Formation Cause of the East China Sea Submarine Topography

作　　者：刘忠臣[1] 陈义兰[1] 丁继胜[1] 张卫红[1] 吴永亭[1] 郭发滨[1] 

机构地区：[1]国家海洋局第一海洋研究所,山东青岛266061

出　　处：《海洋科学进展》2003年第2期160-173,共14页Advances in Marine Science

基　　金：国家海洋局青年基金资助项目--晚第四纪东海潮流沙脊发育与海平面升降的响应(2000505)

摘　　要：东海一直以其特殊的大地构造地位受到国内外地学界的关注,但作为主要受构造控制的东海海底地形的研究,以往简单趋势性描述居多,专门深入系统的研究尚不多见。不久前完成的高精度、全覆盖多波束海底地形勘测覆盖了东海部分外陆架、大陆坡全部、冲绳海槽和东部岛坡的一部分,取得了海量的测深数据。据此编绘的勘测多波束水深图和结合测区外的传统资料编绘的海底地形图使我们有机会可以重新审视和系统研究东海的海底地形特征。在定量确定了陆架坡折线、陆坡坡脚线和东部槽坡坡脚线的基础上划分出了大陆架、大陆坡、冲绳海槽平原和东部岛坡4大地形区,继之对各区的海底地形特征进行了研究和描述,并在区内选取了有代表性的5条剖面进行了剖析。另外,从地球内营力和外营力两方面分析了影响东海海底地形发育的因素。调查分析表明:整个东海地形分带明显,地形类型多样:大陆架十分宽阔,总体北宽南窄,从大陆向海平缓倾斜,发育了广泛的NW-SE向沙脊群,自大陆向东南呈扇形发散;大陆坡呈NE-SW向条带展布,海底地形陡峻,呈阶梯状下掉,总体北缓南陡,其上峡谷密布,上穿切外陆架,下直达海槽,同时坡麓上海台沟谷伴生发育;冲绳海槽北浅南深,其内在平坦的背景上发育了众多的海山和海丘,其中心又有槽中槽地形;东槽坡地形复杂。Based on the multi-beam bathymetric data observed in the East China Sea during 1997 to 2001, the East China Sea submarine topographic characteristics were reviewed and analyzed systematically. Based on the above analysis and study, the East China Sea submarine topography can be divided into 4 topographic areas, namely, continental shelf, continental slope, the Okinawa Trough plain and eastern island slope. In this paper, the submarine topographic characteristics of different topographic areas are analysed and described, 5 representative profiles are analysed, and the factors affecting the East China Sea submarine topographic development are also analysed. Several new understandings or corrections for the East China Sea submarine topography are suggested, and they include (1) the shelf break line is determined to be at 160 m depth rather than 200 m depth, the boundary line between inner shelf and outer shelf is at 50 m depth, and the continental slope toe line is getting deeper from north to south with a depth range of 600 to 1800 m; (2) the large sand ridges were found to occupy most of outer shelf area, which is different from the knowledge of regional and single sand ridge; (3) it is shown from the survey results that there are not Hupi Reef and Ya Reef on the northern shelf, but Pingyan Reef was found there; (4) 16 huge canyons were determined on the continental shelf south of 28 °10′N, among them, 3 new canyons were discovered; (5) depressions in the southern Okinawa Trough were delineated, and new active valcanos were found in some depressions; (6) the maximum water depth is determined to be located in the depression in the southern Okinawa Trough (25 °13.2 ′N, 124 °45.0 ′E) with a depth value of 2322 m, which is slightly shallower than the accepted depth; (7) several new seamounts were found on the continental shelf and in the trough.

关 键 词：东海 海底地形 分区特征 多波束勘测 大陆架 大陆坡 冲绳海槽 东部岛坡 海底峡谷 

分 类 号：P722.6[天文地球—海洋科学] P736.12