VEI
Noun
Meaning
VEI
Volcanic Explosivity Index: a scale used to measure the explosiveness of volcanic events, based on the amount of material which is erupted.
Examples
As such there is a discontinuity in the definition of the VEI between indices 1 and 2. The lower border of the volume of ejecta jumps by a factor of 100 from convert while the factor is 10 between all higher indices.
Another weakness of the VEI is that it does not take into account the power output of an eruption, which makes the VEI extremely difficult to determine with prehistoric or unobserved eruptions.
About 90% of these 7,742 eruptions have a VEI of 3 or less.
In the following table, the frequency of each VEI indicates the approximate frequency of new eruptions of that VEI or higher.
Known supereruptions Cross-section through Long Valley Caldera VEI 8 Based on incomplete statistics, at least 60 VEI 8 eruptions have been identified.
The scale is logarithmic from VEI 2 and up; an increase of 1 index indicates an eruption that is 10 times as powerful.