Eruption history
Three extremely large eruptions have taken place in the last 2.1 million years. The most recent was approx. 70,000 years ago. The largest of these flows caused Pitchstone plateau. 640,000 years ago there was a giant-caldera forming eruption. We don't know the exact year for the last large eruption.
Many of these eruptions were separated in time by several tens of thousands of years. The evidence of earlier eruptions may have been either buried or destroyed , what we don't know is how often the volcano has actually erupted. Lava flows would have covered up to 30-40 miles, ash lingering within the United States. It could have possibly killed over a million people (57*25,000; used Mt. Helens data & multiplied it) and caused severe damage.
Many of these eruptions were separated in time by several tens of thousands of years. The evidence of earlier eruptions may have been either buried or destroyed , what we don't know is how often the volcano has actually erupted. Lava flows would have covered up to 30-40 miles, ash lingering within the United States. It could have possibly killed over a million people (57*25,000; used Mt. Helens data & multiplied it) and caused severe damage.
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