Why Mt. Hood Never Erupts With A Bang

Feb 15, 2012

MT. HOOD, Ore. -- Researchers at Oregon State University think they have figured out why Mt. Hood doesn’t erupt with the same bang and violence as other Cascade volcanoes. Amelia Templeton reports.

From a distance, Mt. Hood looks like the rest of the Cascades volcanoes. But if you look closely around the base of the mountain, you don’t find big deposits of ash and pumice typical of volcanoes in the northwest. Alison Koleszar, an OSU researcher, says Hood tends to ooze, instead of explode.

Koleszar: “Most of the eruptions at Hood over the past 30 thousand years have all occurred in about the same way, and that’s lava oozes up, so it forms a big lava dome, a blister of lava, near the top of the volcano.“

Koleszar studied crystals that form in volcanic rock. She learned that before eruptions at Mt Hood, hot material rises from deep beneath the mountain. That makes the magma under Hood hotter and runnier. The runny magma is pushed up out of the volcano more easily, explaining Hood’s history of polite eruptions.

Copyright 2012 Northwest News Network