Illustrated Volcano Glossary

Updated: Nov 29, 2023 05:30 GMT - refresh

effusive: Volcanology: effusive (volcanic) eruption

Lava flow at Mt Etna volcano - a typical effusive eruption

Effusive 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. Read all

Related keywords (2):
Etna - explosive
explosive: Volcanology: explosive (volcanic) eruption

A small explosive eruption at Mt Etna volcano

Explosive eruptions occur, when the erupting magma is ejected as fragments into the air, as opposed to effusive eruptions producing lava flows.

Explosive eruptions are called so, when the erupting magma is fragmented when exiting the conduit. The reason are expanding gasses from the magma itself or external water e.g. from an aquifer. The resulting fragments of the magma itself are called tephra, and consist in small and large pieces: Ash, lapilli and bombs are the typical products of explosive eruptions.
The reason for explosive eruptio... Read all

Related keywords (9):
ash - bomb - effusive - lava fountain - magma - Plinian eruption - Pumice - pyroclastic flow - viscosity

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