Question

In the Pacific Northwest of the United States, there is a long chain of volcanoes.Why did they form?

Answer 1

The Pacific plate and North American plate are moving sideways past each other.

Answer 2

Answer:

A. The Pacific plate is being subducted under the North American plate.

Explanation:

The distribution of volcanoes among the northwest all the way up to Alaska is due to the crashing of two tectonic plates. In the northwest, one of the pacific plates, specifically the oceanic Farallon Plate is being subdued or pushed under the North American Plate. When this happens, rocks beneath the surface melt and become magma, which raises to the surface to build volcanoes.