An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) The state or quality of being explosive.
2) A measure of the extent to which a material is explosive.

→ explosive; → -ity.

A logarithmic scale, ranging from 1 to 8, used to measure the intensity of volcano eruptions. The VEI is based on several factors: the degree of fragmentation of the volcanic products released by the eruption, the amounts of sulfur-rich gases that form stratospheric aerosols, the volume of the eruptions, their duration, and the height is reached. The largest eruptions (8) produce an amount of bulk volume of ejected → tephra of ~ 1,000 km³.

→ volcanic; → explosivity; → index.