Vulnerable ocean ecosystems also include deep-sea trenches, formed in areas of seafloor spreading where two tectonic plates collide and the crust is destroyed within the hot interior of the Earth.
190.　脆弱的海洋生态系统中还有深海海沟，它们是在两个地壳构造板块相撞、地壳陷入地球灼热的内层的海底扩展区形成的。