From 0 to ERUPTION in 60 days: You thought that volcano was COLD?

theregister.co.uk ^ | 17th February 2014 | Brid-Aine Parnell,

[BenLurkin]

New research on Mount Hood in Oregon suggests that volcanoes can come up with liquid hot magma in as little as a couple of months, but most of the time, they contain magma that has been kept cool for thousands of years.

"If the temperature of the rock is too cold, the magma is like peanut butter in a refrigerator," said Adam Ken, an Oregon State University (OSU) geologist.

"It just isn't very mobile. For Mount Hood, the threshold seems to be about 750 degrees C - if it warms up just 50 to 75 degrees above that, it greatly decreases the viscosity of the magma and makes it easier to mobilise."

The key is when much hotter magma from deep within the Earth's crust comes up to meet the jellied magma four or five kilometres below the surface. The mixing of hot and cold is what triggered the last two eruptions at Mount Hood 220 and 1,500 years ago.

...

"What is encouraging from another standpoint is that modern technology should be able to detect when magma is beginning to liquefy, or mobilise," Kent said, "and that may give us warning of a potential eruption. Monitoring gases, utilising seismic waves and studying ground deformation through GPS are a few of the techniques that could tell us that things are warming."

The full study, "Rapid remobilisation of magmatic crystals kept in cold storage", was published in Nature. ®

[Salvation]

If you would like more information about Oregon, please FReepmail me. I lost my Oregon list when my computer crashed recently.

[Conan the Librarian]

Good Point! He got a lot of hate mail for it too.