Why did Mt. Saint Helen almost self-destruct instead of erupting like we know most volcanoes to?

Question

I didn’t know about Mt. Saint Helen today, and watching the videos, it feels almost unreal. What’s the science behind it?

In: Geology

Answer 1

You’re probably thinking that Hawaiian-style volcanoes, with flowing lava, are the most common form of volcanoes, and they’re not. The pyroclastic granite type like Mt. Saint Helens, the ones that go BOOM, are far more common. The difference is primarily the chemical nature of the rock/magma involved.