A trench in science is usually a long, narrow, deep depression in the Earth’s surface, especially on the ocean floor. In geology, ocean trenches are often formed where one tectonic plate moves beneath another at a subduction zone.

Quick Scoop

  • Meaning: A trench is a deep, narrow dip or valley, longer than it is wide.
  • Science use: In Earth science, it usually means an ocean trench.
  • How it forms: Most ocean trenches form from plate tectonics , especially subduction.
  • Why it matters: Trenches help scientists study earthquakes, volcanoes, and Earth’s internal structure.

Simple example

The Mariana Trench is one of the deepest ocean trenches and is a classic example of this science meaning of “trench”.

If you want, I can also explain the difference between a geology trench and a construction trench.