When will Yellowstone blow?

Answer 1

Yellowstone National Park sits on top of one of the largest, most active, and potentially most explosive volcanoes in the world. The caldera of the volcano is roughly 28x47 miles in size, centered roughly under Yellowstone Lake. The last known eruption, a relatively minor event, occurred about 70,000 years ago.

There have been three "super eruptions" of Yellowstone over the past 2.1 million years, each with an interval of about 660,000 - 800,000 years. The last giant caldera-forming super eruption occurred about 640,000 years ago. Those looking for patterns point out that we are due for another super eruption, based on the past interval. However, there is no evidence to suggest that Yellowstone's eruptions are cyclical. There currently is no way to predict when Yellowstone will next erupt, but when it does, it most likely will not be the super eruption people speak about. Seismic studies suggest that the magma chamber under Yellowstone is cooling and a large portion of the magma has solidified, making a large eruption highly unlikely.

If a super eruption does occur, however, it will smother much of the United States and change weather patterns throughout the world for years, displacing an estimated 1,000 times more rock and ash than the Mount St. Helen's eruption of 1980.