Global Volcanism Program

The andesitic-dacitic Mount Adams stratovolcano is second in volume only to Mount Shasta in the Cascade Range. The volcanic complex is elongated along a NNW-SSE line, and includes more than 60 flank vents over 200 km2. Volcanism began about 940 ka, with three main cone-building stages occurring at about 500, 450, and 30 ka. It was active throughout the Holocene, producing two dozen minor explosive eruptions from summit and flank vents. Six Holocene lava flows are located on the flanks between 2,100 and 2,600 m elevation. The most voluminous Holocene lava flows, some of which traveled 10 km or more, were emplaced between about 7,000 and 4,000 years ago. The latest eruption about 1,000 years ago produced a minor tephra layer and possibly a small lava flow down the E flank.

Global Volcanism Program

World map showing location of the volcanoes and countries

Global Volcanism Program (@SmithsonianGVP) / X

Global Volcanism Program

Global Volcanism Program Bulletin of the Global Volcanism Network

Timeline of eruption history based on the Global Volcanism Program

Global Volcanism Program - Wikipedia

Global Volcanism Program Bulletin of the Global Volcanism Network

Global Volcanism Program - Interested in what volcanoes are active

Plume from Lascar volcano, April 1993 eruption. NOAA image

4 Seismic map of the 2018 eruption The Global Volcanism Program

Global Volcanism Program

Global Volcanism Program - Report from the Bulletin of the Global

Global Volcanism Program (@SmithsonianGVP) / X