通常深海沟呈向海凸出的缓弧形,然而,海沟-海沟连接处则向陆凸出,共呈尖角状。每条主要海沟系中都可见到这种不对称波状形态。海沟的形状和岩石圈下倾板片的形状都是不对称的。弧-弧连接处的岩石圈板片急剧弯曲,而连接点之间的板片则向下缓曲。图1列举了两个按和达-贝尼奥夫带的等深线表示的弧-弧连接处急剧弯曲的俯冲板片。在千岛和日本的连接处,和日本和伊豆-小笠原的连 Often, the deep trench presents a gentle arc to the sea, however, the trench-trench junction projects to the land with a sharp-pointed shape. This asymmetrical wavy pattern can be seen in every major trench. Both the shape of the trench and the shape of the leeward plate under the lithosphere are asymmetrical. The lithospheric plates at the arc-arc junction curve sharply, while the plates between the connection points slowly curve downward. Figure 1 shows two subducting slabs that curve sharply at the arc-arc connection, represented by the isobath of the Wabel-Benioff strip. At the junction of Kuril and Japan, with Japan and Izu - Ogasawara company