Yellowstone sits on top of four overlapping calderas which has been created during the large eruptions which took place 2.1 million, 1.3 million, and 640,000 years ago. These calderas lie right over a hotspot from where there has been a succession of eruptions which has created the eastern part of the Snake River Plains which was once a mountainous region. Calderas are defined as structures which have been created by the collapse of the overlying land into the emptied magma chamber after the volcanic eruption.
The present Yellowstone Park rests on a crater forming caldera which was formed 640,000 years ago when the volcano last erupted. The caldera and a major chunk of the national park are located in the northwest corner of Wyoming. The caldera measures about 34 by 45 miles. The caldera which was formed during the first eruption 2.1 million years ago formed the Hukleberry ridge Tuff and the Island Park Caldera. The second eruption which happened 1.3 million years ago created the Henry’s Fork Caldera and the Mesa Falls Tuff.The final eruption as stated happened 640,000 years ago, which created the Yellowstone Caldera and the Lava Creek Tuff.
Will the Yellowstone Supervolcano erupt in future? Some experts feel that the next Yellowstone eruption will have catastrophic effects on the planet and could wipe out life. However researchers have now confirmed that the situation will not be as bad as it has been predicated. A ground breaking computer simulation program which has been code named Ash3D has been used to study the effects of a future volcanic eruption in Yellowstone.
Based on the data provided by the computer, research team from United States Geological Survey has said that the impact of Yellowstone supervolcano might be much less compared to earlier estimates. The chance of a supervolcano eruption in the coming centuries is very low. However the situation can change if there is a major earthquake which shifts the geological plates.