The paper points out that it is necessary to further study the gradient change of ~(14)C concen-tration in surface and deepwater in the middle and southern section of the philippine Trench.

• 文章还指出进一步开展菲律宾海沟中-南段海域表层、深层海水~(14)C 浓度变化梯度研究的必要性。