deep-sea trench

deep-sea trench

Any long, narrow, steep-sided depression in the ocean bottom in which maximum oceanic depths (24,000–36,000 ft, or 7,000–11,000 m) occur. The deepest known depression of this kind is the Mariana Trench. Most trenches occur at subduction zones, where one tectonic plate is thrust under another.


deep-sea trench or oceanic trench

This entry comes from Encyclopædia Britannica Concise.
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