Feeds

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

Liquid hot MAG...MMMMA

Intelligent flash storage arrays

Volcanoes can become ready to blow in less time than scientists had previously thought, but their magma is usually kept in a cool, near-solid state.

Volcano erupting

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.

Mount Hood's eruptions aren't particularly violent, the magma tends to ooze instead of exploding, which is down to the different compositions of the two magmas, according to a previous OSU study.

"What happens when they mix is what happens when you squeeze a tube of toothpaste in the middle," said Kent. "A big glob kind of plops out the top, but in the case of Mount Hood, it doesn't blow the mountain to pieces."

The mobility of the magma depends on the amount of crystallisation - when it is more than 50 per cent crystalline, it's rendered immobile - which in turn depends on the temperature.

"People think about there being this big reservoir of liquid magma under a volcano, but we don't think it's in that state all the time," said Kari Cooper, associate professor in the Department of Earth and Planetary Sciences at UC Davis and lead author of the study.

Cooper and Kent figured out that Mount Hood's magma could be mobile as little as one per cent of the time, and definitely less than ten per cent, by studying the radioactive isotopes and distribution of trace elements in rocks ejected from previous eruptions.

The study could lead to better predictions by volcanologists, who can used seismic or other remote imaging techniques to look for whether the magma is liquid or semi-solid. The scientists plan to do further studies at other volcanoes to ensure the pattern repeats at other sites.

"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. ®

Providing a secure and efficient Helpdesk

More from The Register

next story
SECRET U.S. 'SPACE WARPLANE' set to return from SPY MISSION
Robot minishuttle X-37B returns after almost 2 years in orbit
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
LOHAN crash lands on CNN
Overflies Die Welt en route to lively US news vid
You can crunch it all you like, but the answer is NOT always in the data
Hear that, 'data journalists'? Our analytics prof holds forth
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
Origins of SEXUAL INTERCOURSE fished out of SCOTTISH LAKE
Fossil find proves it first happened 385 million years ago
America's super-secret X-37B plane returns to Earth after nearly TWO YEARS aloft
674 days in space for US Air Force's mystery orbital vehicle
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.