Deep Ocean Trenches: The Subduction Zones In contrast to mid--ocean ridges, deep ocean trenches form at convergent plate boundaries, where one plate descends, or 'subducts, ' beneath another.

深海海沟：俯冲带 与洋中脊相反，深海海沟形成于会聚板块边界处，其中一个板块下降或“俯冲”到另一个板块下方。