Question

The characteristics of deep trenches indicate __________.

(a) they are erosional features similar to the Grand Canyon in Arizona
(b) they are elongated subduction-related creases in the oceanic crust
(c) they are glacial troughs dating back to the Ice Age
(d) they are erosional canyons cut by turbidity currents

Answer 1

Deep trenches in the ocean floor are indicators of subduction zones, where one tectonic plate is being forced under another, not features created by erosion or glaciers.

Step-by-step explanation:

The characteristics of deep trenches indicate they are elongated subduction-related creases in the oceanic crust. Contrary to erosional features such as the Grand Canyon, which were mainly carved by flowing water, oceanic trenches are typically associated with convergent plate boundaries, where one tectonic plate is forced beneath another into the mantle. These trenches are not the result of erosion by water or glaciers but are a key feature of plate tectonics and are among the deepest parts of the ocean floor.