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LITHOEN

Volcano

Mount St. Helens

A stratovolcano of the Cascade Range in Washington State, and the standard illustration of how magma composition governs whether an eruption flows or explodes.

Classification

edifice
stratovolcano

How this record is known

1
Directly recorded
Observed or measured, reported by the party that made the observation.
1
Settled consensus
Cited as the accepted position of the discipline.

2 of 2 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.

What Lithoen records

Each claim states how it is known and cites its evidence.

EstablishedBasalt to rhyodacite.

Mount St. Helens erupts material ranging in composition from basalt to rhyodacite — a range that spans the runny and the viscous, and so the effusive and the explosive.

Evidence support: Supported by the cited evidence 2 sources, multiple sources, independence unknown

Evidence: U.S. Geological Survey n.d. Primary authority; U.S. Geological Survey n.d. Primary authority

Measured2,539 m

The USGS records Mount St. Helens as a stratovolcano with a composition ranging from basalt to rhyodacite, and a summit elevation of 2,539 metres.

  • method: Elevation as published in the USGS volcano profile’s Quick Facts.
  • precision note: Summit elevation following the 1980 eruption, as currently published.

Evidence support: Supported by the cited evidence one source

Evidence: U.S. Geological Survey n.d. Primary authority

In the knowledge graph

Record last updated 2026-09-06. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.