Parameter Tree:
EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > TRENCHES

Definition:
Trenches are long, deep (6,000-11,000m/20,000-36,000ft), and narrow depression
of the sea floor with relatively steep sides, associated with a subduction
zone. The deepest of all ocean trenches, is the Mariana Trench (11,020 m/36,000
ft).


Reference:
Alyn C. Duxbury, Alison B. Duxbury, and Keith A. Sverdrup. An Introduction to
the World's Oceans. 6th edition. McGraw-Hill Higher Education, 2000.