{"thcode":3,"term":{"code":756,"name":"ocean trenches","parent":1010,"scope":"Narrow, elongate depressions of the deep-sea floor associated with a subduction zone. They are oriented parallel to volcanic arcs and commonly to the edge of the continent, between the continental margin and the abyssal hills. [Glossary of Geology, 4th ed.]"},"uf":[{"name":"deep-sea trenches","usewith":false},{"name":"deeps (ocean)","usewith":false},{"name":"trenches (seafloor)","usewith":false},{"name":"troughs (seafloor)","usewith":false}],"bt":[{"code":1010,"name":"seafloor features","parent":816,"scope":null},{"code":816,"name":"physiographic features","parent":1,"scope":null},{"code":1,"name":"Categories","parent":null,"scope":null}],"nt":[],"rt":[{"code":1106,"name":"submarine canyons","parent":1010,"scope":"Steep-sided, V-profile valley often heading in the continental shelf running down the continental slope, having tributaries and resembling unglaciated, river-cut land canyons. [Glossary of Geology, 4th ed.]"}]}