摘要
渤海东部发育了典型的潮流动力地貌体系，它由老铁山水道冲刷槽、辽东浅滩沙脊和渤中浅滩沙席三者组成。前者为潮流侵蚀区，后两者为潮流沉积区。老铁山水道表层最大流速可达５ｋｎ，潮流强烈侵蚀海底；辽东浅滩表层最大流速１．３～２．３ｋｎ，Ｍ２分潮椭率绝对值小于０．４，潮流往复性强，形成潮流沙脊；渤中浅滩表层最大流速为１．２～１．６ｋｎ，Ｍ２分期椭率绝对值大于０．４，潮流旋转性强，形成潮流沙席。６号沙脊南端详测区的旁侧声纳镶嵌日显示的微地貌形态有海底沙丘、沙条、彗星尾标志和冲刷沟，表明沙席和沙脊均是现代潮流作用形成的底形。该潮流动力地貌体系中，净沉积物搬运从老铁山水道至两潮流浅滩；在详测区净沉积物搬运从南向北。
An integrated and typical dynamic geomorphologic system of tidal bed forms has developed in the east part of the Bobal Sea. It consists of the Laotieshan Channel, the Liaodong Shoal and the Bozhong Shoal. The first is a tidal current scour region and the latter two are tidal current depositional regions. The maximum tidal current velocity is up to 5 knots in the Laotieshan Channel where strong erosion occurs. In the Liaodong Shoal the maximum tidal current velocity is 1. 3～2. 3 knots and the absolute value of M2 tidal current ellipticity is less than 0. 4, which indicatis that the reciprocating tidal currents in throng enough for forming tidal salld ridges. In the Bozhong Shoal the maximum tidal velocity is 1. 2～1. 6 knots and the absolute value of M2 tidal current ellipticity is larger than 0. 4, which indicates that rotation of tidal currents increases so as to form tidal sand sheets. The small-scale bedforms Surveyed in detail in the area and shown in the side scan sonar mosaic are subaqueous dunes, sand ribbons, comet-tail marks and scour furrows, which indicates that both the sand ridges and sand sheet are still under the action of tidal current processes at present. The net direction of sediment transportation within this system is from the channel to the two shoals, whereas that in the detailed survey area is from south to north.
出处
《黄渤海海洋》
CSCD
1996年第1期7-21,共15页
Journal of Oceanography of Huanghai & Bohai Seas
基金
国家自然科学基金
国家海洋局资助
法国IFREMER资助
关键词
渤海
潮流
潮流沙脊
动力地貌
海底地貌
Tidal sand ridges Tidal sand sheets The eastern Bobal Sea The dynamic geomorphic system
