Why are earthquakes not as forceful near ocean ridges compared to ocean trenches?

Question

Rock near ridges is heated and softer than denser hardened rock that is pulled into trenches.

There is very little movement of rock near ocean ridges but more rock movement near trenches.

Rock near ridges is cooled rapidly and loses its volcanic explosiveness but becomes heated near trenches.

Rocks near ridges is expanding and rock near trenches is compacted.

Answer 1

The most accurate explanation for why earthquakes are generally not as forceful near ocean ridges compared to ocean trenches is:

Rock near ridges is heated and softer than denser hardened rock that is pulled into trenches.

At ocean ridges, tectonic plates are diverging, which results in the formation of new crust as magma rises to the surface. This process typically involves less friction and less forceful movement, leading to smaller magnitude earthquakes. The rocks at the ridges are often hotter and more ductile, which means they can deform without breaking, resulting in lower energy release compared to areas where plates are converging.

On the other hand, ocean trenches are areas where one tectonic plate is being subducted beneath another. This process involves the compression and intense friction of denser, cooler, and more brittle rock. The resulting stress can lead to more significant earthquakes, making them typically more powerful than those occurring at ocean ridges.

Overall, the nature of the rocks and the type of tectonic activity—divergent at ridges versus convergent at trenches—plays a critical role in the magnitude and forcefulness of earthquakes.