^(10)Be在大洋边缘海洋学中的应用及模型

APPLICATION AND MODELS OF COSMOGENIC NUCLIDE ^(10)Be IN MARGINAL SEA RESEARCH

主要讨论宇宙射线成因核素10 Be(T1 2 =1 .5Ma)在大洋边缘海洋学尤其是中国近海海洋研究中的应用。在过去的近 2 0年中 ,在中国开展的10 Be研究在黄土堆积年龄及地层对比方面获得了诸多成果 ,但在海洋方面的应用研究距国际水平仍有一定的差距 ,尚需进一步加强。综述了海洋环境中10 Be作为一个地球化学示踪剂的研究现状 ,着重介绍10 Be在中国东部海域的收支平衡模式以及讨论10

The potential application of the cosmogenic nuclide 10 Be in marginal seas and island-arc system study has been discussed. Dissolved beryllium 10 concentration profiles in seawaters of the East China sea and the Kuroshio have been investigated. The results show that 10 Be concentrations in this area are mainly controlled by surface biological productivity, partical remineralization, and the degree of mixing with Changjiang River (the Yangtze river) and Kuroshio waters. Generally the 10 Be water depth profiles can be divided into three layers: the surface mixing layer, the particulate 10 Be regeneration layer and the bottom layer. Surface water 10 Be concentrations increase gradually towards the Okinawa Trough and increase sharply at the edge of the Kuroshio Current. Vertical distributions of 10 Be show that 10 Be is enriched in the bottom waters near the Yangtze river estuary and the central continental shelf. Box model results indicate that 10 Be input from the Kuroshio current is more important than Yangtze river input and atmospheric precipitation. About 81% of the 10 Be input to the East China sea is scavenged into the sediments and 19% of the 10 Be flows out of the East China sea by currents and water exchange. The 10 Be sedimentation flux in the East China sea is nearly five times of the average global 10 Be production rate. Therefore the East China sea may be an important sink for 10 Be.