How Many? A Dictionary of Units of Measurement
© Russ Rowlett and the University of North Carolina at Chapel Hill

Table of Contents
About the Dictionary
Using the Dictionary

Volcanic Explosivity Index

This scale is designed to express the severity of volcanic eruptions.

Source: Volcano World, an educational site at the University of North Dakota.

VEI

Description

Plume Height

Volume

Classification

How often

Example

0

non-explosive

< 100 m

1000s m3

Hawaiian

daily

Kilauea

1

gentle

100-1000 m

10 000s m3

Haw/Strombolian

daily

Stromboli

2

explosive

1-5 km

1 000 000s m3

Strom/Vulcanian

weekly

Galeras, 1992

3

severe

3-15 km

10 000 000s m3

Vulcanian

yearly

Ruiz, 1985

4

cataclysmic

10-25 km

100 000 000s m3

Vulc/Plinian

10s of years

Galunggung, 1982

5

paroxysmal

> 25 km

1 km3

Plinian

100s of years

St. Helens, 1981

6

colossal

> 25 km

10s km3

Plin/Ultra-Plinian

100s of years

Krakatau, 1883

7

super-colossal

> 25 km

100s km3

Ultra-Plinian

1000s of years

Tambora, 1815

8

mega-colossal

> 25 km

1 000s km3

Ultra-Plinian

10 000s of years

Yellowstone, 2 Ma

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