Illustrated Volcano Glossary
- Volcanology: effusive (volcanic) eruptionEffusive means flowing out of lava as opposed to explosive eruptions.
If magma is sufficiently fluid and if it is not framented by expanding gasses when reaching the surface vent, it can erupt to form lava flows. This is called effusive eruption. The opposite of effusive is explosive, i.e. fragmentation of magma.