末次冰消期以来东黄海暖流系统的演化

EVOLUTION PATTERN OF WARM CURRENT SYSTEM OF THE EAST CHINA SEA AND THE YELLOW SEA SINCE THE LAST DEGLACIATION

以黑潮为主干的东黄海暖流系统，所携带的高温高盐水对我国近海的海洋环境和大气环流格局产生了重大影响。为系统重建由黑潮暖流、对马暖流和黄海暖流组成的东黄海暖流系统在末次冰消期以来的演化过程，建立末次冰消期以来东黄海暖流系统的演化模式，对取自黑潮主流轴附近的DGKS9603孔、现代对马暖流边缘的CSH1孔和与黄海暖流相伴生的冷水体下面的泥质沉积区YSDP102孔的古海洋记录进行综合分析研究。结果表明，现代东黄海暖流系统是伴随着末次冰消期以来黑潮的演化和海平面的脉冲式上升而形成与演化的，地理边界条件是非常重要的控制因素。16kaB．P．黑潮对冲绳海槽的影响开始加强，之后随着海平面的上升，对马暖流开始发育，到8．5kaB．P．左右，现代对马暖流正式形成，期间黑潮暖流经历了Heinrich 1和Younger Dryas事件的两次减弱过程。7—6kaB．P．是黑潮暖流和对马暖流末次冰消期以来最强盛的时期；约6．4kaB．P．左右黄海暖流开始出现，至此东黄海暖流系统的基本格局已完全形成；在5．3—2．8kaB．P．期间，冲绳海槽发生了以“Pulleniatina低值事件”为标志的黑潮变弱过程，导致对马暖流主流轴在3kaB．P．左右发生了一次向太平洋方向的偏转事件，低温、高营养物质含量的陆架冷水团对冲绳海槽北部影响加强，期间在黄海暖流附近冷水体下面堆积了巨厚的泥质沉积体系。此后，由黑潮暖流、对马暖流和黄海暖流组成的东黄海暖流系统显著加强，直至达到现代的态势。

The warm current system composed of the Kuroshio, the Tsushima Warm Current, and the Yellow Sea Warm Currents, with high temperature and high salinity waters, has played an important role in controlling the oceangraphic environment and atmosphere circumfluence pattern in the East China Sea and the Yellow Sea. To reconstruct the evolution process of the system since the last deglaciation, the paleoceangraphic records in cores DGKS9603, CSH1, and YSDP102, which were retrieved from the mainstream of the Kuroshio, the edge of the modern Tsushima Warm Current, and the muddy region under cold waters accreted with the Yellow Sea Warm Current respectively, were synthetically analyzed. The results indicate that the formation and evolution of the modern warm current system of the East China Sea and the Yellow Sea has been accompanied by the development of the Kuroshio and impulse rising of the sea level since the last deglaciation, thereby, geographical boundary condition was also an important control factor on the variation of the warm current system. The influence of the Kuroshio on the Okinawa Trough had enhanced since 16.0kaB. P., and synchronously the modern Tsushima Warm Current began to develop along with the rising of sea level and finally formed at about 8.5kaB. P. During the period from 16.0kaB. P. to 8.5kaB. P., the Kuroshio had experienced two weakening processes during the Heinrich event 1 and the Younger Drays event. The period of 7 - 6kaB. P. was the strongest stage of the Kuroshio and the Tsushima Warm Current since the last deglaciation. The Yellow Sea Warm Current has appeared at about 6. 4kaB. P., when the warm current system of the East China Sea and the Yellow Sea has ultimately formed. The weakness of the Kuroshio, indicated by the occurrence of PuUeniatina Minimum Event during the period from 5.3kaB. P. to 2.8kaB. P., resulted in the cxcursion eastward to the Pacific Ocean of the mainstream axis of the Tsushima Warm Current at about 3.0kaB. P. （onsequently, the influence of continental shelf freshwater with low salinity and high nutrition material on the northern Okinawa Trough had increased. During this period, the gigantic thickness muddy sedimentation system had accumulated under the cold waters companying with the Yellow Sea Warm Current. Thereafter, the warm current system of the East China Sea and the Yellow Sea composed of the Kuroshio, the Tsushima Warm Current and the Yellow Sea Warm Current has reinforced evidently, and reached its modern condition.