Question

Which among the following statements is/are true with reference to oceanic trenches?

• A. They are long-narrow depressions on the seafloor and form the deepest natural parts of the Earth.
• B. They are formed by the process of subduction.
• C. They account for a significant part of Earth’s seismic activity.
• D. They are home to a large number of marine creatures.

Answer 1

Answer: (A), (B), (C)

The correct options are
A They are long-narrow depressions on the seafloor and form the deepest natural parts of the Earth.
B They are formed by the process of subduction.
C They account for a significant part of Earth’s seismic activity.

Oceanic trenches are long-narrow, steep depressions on the sea floor. They are formed as a result of tectonic activity, which describes the movement of the Earth’s lithosphere. This process is called subduction. Much of the world’s seismic activity take place in subduction zones. They have devastating impacts on coastal communities and even the global economy. Taking into account the extreme conditions, very few marine creatures have adapted themselves to survive in such harsh ecosystems.