The volcanic explosivity index (VEI) is a scale used to measure the size of explosive volcanic eruptions. It was devised by Christopher G. Newhall of the United States Geological Survey and Stephen Self in 1982.

Aug 5, 2022 · The Volcanic Explosivity Index (VEI) is a scale that describes the size of explosive volcanic eruptions based on magnitude and intensity. The numerical scale (from 0 to 8) is a logarithmic scale, and is generally analogous to the Richter and other magnitude scales for the size of earthquakes.

Dec 26, 2022 · A common scale for expressing the size of an explosive volcanic eruption is the VEI—Volcanic Explosivity Index. Eruption size can’t be determined by instruments, so this scale is based on a combination of measurements and observations.

With each step in the scale representing an explosivity increase of 10X, a VEI 5 is roughly ten times more explosive than a VEI 4. Two steps of the scale is an increase of 100X in explosivity.

Volcanic Explosivity Index (VEI) is a numeric scale that measures the relative explosivity of historic eruptions. Volume of products, eruption cloud height, and qualitative observations (using terms ranging from "gentle" to "mega-colossal") are used to determine the explosivity value.

In volcanology, the Volcanic Explosivity Index (VEI) is the way to measure the strength of a volcanic eruption. The Volcanic Explosivity Index measures how large or strong volcanic eruptions are. The index is a scale of 0 to 8. 0 is very small, and 8 is huge and very rare.

Dec 26, 2022 · Criteria for estimation of the Volcanic Explosivity Index (VEI). Modified from: Newhall, C.G., and Self, S., 1982, The volcanic explosivity index (VEI): An estimate of explosive magnitude for historical volcanism. Journal of Geophysical Research, v. 87, no. C2, p. 1231–1238, https://doi.org/10.1029/JC087iC02p01231.

The United States Geological Survey (USGS) provides a freely downloadable Volcanic Explosivity Index (VEI) that describes the size of an explosive volcanic eruption.

Sep 6, 2016 · Volcanologists have developed a logarithmic scale called the volcanic explosivity index (VEI) to measure the intensity of an eruption. Eruptive episodes are rated from 0 to 8, however, because the scale is logarithmic, an eruption classified as a 2 on the VEI is ten times more explosive than an eruption rated as a 1, while a VEI of 3 is 100 ...

Since that time, the VEI has been used to classify the size of an eruption, as well as to forecast the potential size of an eruption based on that volcano’s history. The index spans from 0 to 8 and measures the magnitude (erupted volume) and intensity (eruption column height) of an eruption.