海かい膨ぼう

noun

rise; oceanic rise

Oceanographic term for a broad, gently sloping elevation of the seafloor, distinct from a steeper ridge. Used in scientific contexts.

• 東ひがし太たい平へい洋よう海かい膨ぼうは、プレートが拡かく大だいする場ば所しょの一ひとつだ。

  The East Pacific Rise is one of the places where plates spread apart.