Tool · VEI

VEI explorer

Pick a Volcanic Explosivity Index value. The text is limited to what the USGS Yellowstone Volcano Observatory article states. Nothing here is a forecast.

Not a forecast. This page explains published records. It does not say when or where the next earthquake or eruption will happen.

Index value

What USGS says

Select a VEI.

Anchors that stay on the page

The buttons repeat the USGS Yellowstone Volcano Observatory summary. These are the only volume anchors that article states outright. Steps without a named eruption stay unnamed here on purpose.

VEIWhat the cited USGS article states
0Non-explosive lava or dome. Most Hawaiian eruptions, unless there is fountaining or minor ash.
1Small explosive component. This step spans two orders of magnitude.
4Closer to 0.1 km³. La Soufrière 2021. Parícutin is VEI 4 despite 1.3 km³ because it lasted nine years.
5About 1 km³. Mount St. Helens 1980. Hunga Tonga–Hunga Haʻapai 2022 was assigned VEI 5, called preliminary.
6Near 10 km³. Pinatubo 1991.
8More than 1,000 km³. Yellowstone Caldera, 631,000 years ago. Not in this site’s Ring of Fire rectangles.

How to use the result

VEI describes an eruption that scientists have already compared. If a bulletin says “VEI 3,” read the tenfold step here and then read the observatory bulletin for the actual volume. Do not run the explorer backwards to decide what a volcano will do. The long version is the VEI guide. Profiles that match the named examples are Mount St. Helens, Pinatubo, Kīlauea, and Mauna Loa.

Sources