https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf 23.6 2026-03-19T10:41:57.720Z https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/sciencekeywords/36040c6a-5e3a-49fe-b519-162fb77a0fd4 TRENCHES Trenches are long, deep (6,000-11,000m/20,000-36,000ft), and narrow depressionof the sea floor with relatively steep sides, associated with a subductionzone. The deepest of all ocean trenches, is the Mariana Trench (11,020 m/36,000ft).