雅浦–马里亚纳海沟连接处地貌特征研究

Geomorphological characteristics of the junction Yap Trench and Mariana Trench

雅浦海沟是西太平洋“沟–弧–盆”体系的重要组成部分。在雅浦海沟北部,雅浦海沟与马里亚纳海沟呈典型的垂直相交。本文对该海域的地貌进行了详细的研究。结果表明,两条海沟连接处附近,海沟的水深、形态、剖面等都发生明显变化,且具有分段性,两侧斜坡上拥有隆起、凹陷、断裂等地貌,这些特征与海沟连接处特殊的俯冲位置具有密切的联系;通过地貌特征和板块扩张速度判断,20 Ma前帕里西维拉海盆扩张中心应位于137°35′34″E附近,雅浦海沟很可能是由帕里西维拉海盆暴露出来的扩张中心转变而成。

The Yap Trench is an important part of the trench-arc-basin system in the western Pacific Ocean. In the northern part of the Yap Trench, the Yap Trench and the Mariana Trench are typically vertically intersected. The geomorphology of the sea area was studied in detail. The results show that the water depth, morphology and profile of the trenches change obviously near the junction of the two trenches, and have segmented. The slopes on both sides have uplift, depression and fault geomorphology, which are closely related to the special subduction position at the junction of the trenches. In addition, according to the geomorphic characteristics and plate spreading rate, the spreading center of the Parece Vera Basin should be located near 137°35’34’’E before 20 Ma, and the Yap Trench is likely to be transformed from the spreading center exposed by the Parece Vera Basin.