Some really big eruptions happened during Yellowstone’s past, but they all may pale in comparison to a bunch of so-called “super eruptions” that took place in Idaho millions of years ago. According to researchers, these exceptionally massive eruptions happened between 8 and 12 million years ago, and were much, much larger than previously believed, eclipsing a bunch of ancient eruptions that happened in the same general region.
The work was done by researchers with the University of Leicester in conjunction with a team of scientists from a few other universities, including Idaho State, the University of Copenhagen, and the University of California Santa Cruz. The team looked at several different varieties of data, including mineral chemistries and radio isotopes, to reach their conclusion.
There are a total of 12 very large eruptions recorded in the region’s distant past, and the team believes they were much more massive than known. As well, the researchers determined that less than half as many smaller eruptions took place in the Snake River Plain than previously thought.
Said researcher Dr. Tom Knott:
While it is well-know that Yellowstone has erupted catastrophically in recent times perhaps less widely appreciated is that these were just the latest in a protracted history of numerous catastrophic super-eruptions that have burned a track along the Snake River eastwards from Oregon to Yellowstone from 16 Ma to present. The size and magnitude of this newly defined eruption is as large, if not larger, than better known eruptions at Yellowstone, and it is just the first in an emerging record of newly discovered super-eruptions during a period of intense magmatic activity between 8 and 12 million years ago.