GEOL 303 Lecture Notes - Lecture 12: Supervolcano, Mount Pinatubo, Volcanism
Document Summary
Three areas in the u. s. with super-eruptions less than 1 million years old: There is a direct relationship between the volume of material that erupted and the explosivity of the eruptions. These are calderas, and are too large to be produced by the collapse of a single volcano. For a 50km wide caldera, the collapsed volcano would have had a height of ~150,000 ft. Super eruptions are not from a single point source, but rather from a large ring fractures that will form the circular wall of the giant caldera. Yellowstone eruption volumes (from 2. 1 million years ago to 640,00 years ago) 100 to 2500 times more explosive than mt. Last super-eruption at yellowstone was 640,000 years ago. Smaller eruption have occurred since, with the last about 70,000 years ago. Eruption occurred about 760,000 years ago, but since that time it has had scattered small eruptions the resurgent caldera floor.
