Nav: Home

Thermal history of magma may help scientists hone in on volcanic eruption forecasts

June 15, 2017

CORVALLIS, Ore. - Although volcanic eruptions are often quite hazardous, scientists have been unable to pinpoint the processes leading up to major eruptions -- and one important limitation has been a lack of knowledge about the temperature history of the magma.

A new study analyzed crystals of the mineral zircon -- zirconium silicate -- in magma from an eruption in the Taupo Volcanic Zone in New Zealand about 700 years ago to determine the magma's history. The analysis shows the magma went through a comparatively "cool" period for thousands of years before heating up. Once magma temperatures reached 750 degrees Celsius, it was a short amount of time -- decades or less -- before an eruption occurred.

This pattern of long-term crystal storage in near-solid magma, punctuated by rapid heating, is applicable to many other volcanoes around the world, the researchers say, and may begin to help scientists recognize when a volcano is heading toward an eruptive phase.

Results of the research, which was supported by the National Science Foundation, are being reported this week in Science.

"Mobility in magma is a function of temperature and most of the time when it's sitting there in the Earth's crust under the volcano it's cool," said Adam Kent, an Oregon State University geologist and co-author on the study. "Of course, cool is a relative description since it's still some 650 degrees (Celsius). I wouldn't put my finger on it.

"But to erupt onto the Earth's surface magma needs to heat up so it can be runny enough to be squeezed along cracks in the Earth and pushed up to the surface. At lower temperatures, the magma is too crystal-rich and viscous to move. It's like trying to spread cold peanut butter onto a piece of bread. It takes higher temperatures to get things moving -- and then our data show it's only a period of years or decades before it erupts."

Kent said the Taupo magma system has similarities to many volcanoes around the world, including the Cascade Range in the Pacific Northwest of the United States. A past study by Kent and his colleagues using a different approach found that Mt. Hood in Oregon also spent most of its history in a cold, rigid state before moving rapidly into an eruptive phase.

This new study adds more certainty to the method, and provides a new tool to apply this work to other volcanoes the researchers say.

The key to honing in on these long-term geologic processes is understanding the volcanoes' thermal or temperature history, the researchers say. Past studies began making inroads into understanding the history of magma temperatures, but they relied on trying to reconcile data from a sample containing many thousands of individual crystals.

Using zircon crystals, which can be dated through analyzing the decay of uranium and thorium, adds more resolution, or precision, to the process. The crystals are like a "black box" flight recorder for studying volcanic eruptions, according to Kari Cooper of the University of California, Davis, corresponding author on the study.

"Instead of trying to piece together what happened from the wreckage," Cooper said, "the crystals can tell us what was going on while they were below the surface, including the run up to an eruption."

Zircon crystals occur in magma from many volcanoes and the new technique will have wide applications to volcanoes along the ring of fire - the belt of volcanoes that surround the Pacific Ocean - and elsewhere.

"It removes some uncertainty and gives us a great new tool to go back and look at other volcanoes," Kent said.

The finding also suggests that if many volcanoes store their magma in this relatively cold state, recognizing volcanoes where warm and mobile magma is present may help researchers find volcanoes in the early throes of producing future eruptions. The technology to monitor volcanoes using seismic waves and other remote techniques is improving all the time, the researchers said.
-end-
The Science study was led by Allison Rubin and Cooper of the University of California at Davis. Other researchers included Christy Till and Maitrayee Bose of Arizona State University; Fidel Costa, Nanyang Technological University of Singapore; Darren Gravley and Jim Cole of the University of Canterbury in New Zealand; and Chad Deering, Michigan Technological University.

Kent is on the faculty of the College of Earth, Ocean, and Atmospheric Sciences at Oregon State.

Oregon State University

Related Volcanic Eruptions Articles:

A new tool to predict volcanic eruptions
Earth's atmosphere is made up of 78% nitrogen and 21% oxygen, a mixture that is unique in the solar system.
Oral traditions and volcanic eruptions in Australia
In Australia, the onset of human occupation (about 65,000 years?) and dispersion across the continent are the subjects of intense debate and are critical to understanding global human migration routes.
'Crystal clocks' used to time magma storage before volcanic eruptions
The molten rock that feeds volcanoes can be stored in the Earth's crust for as long as a thousand years, a result which may help with volcanic hazard management and better forecasting of when eruptions might occur.
Super volcanic eruptions interrupt ozone recovery
Strong volcanic eruptions, especially when a super volcano erupts, will have a strong impact on ozone, and might interrupt the ozone recovery processes.
Rare volcanic rocks lift lid on dangers of little-studied eruptions
Unusual rocks discovered on a remote mountainside have alerted scientists to the dangers posed by a little-studied type of volcano.
Revising the history of big, climate-altering volcanic eruptions
Researchers have developed a new isotopic method to analyze the recent history of large stratospheric volcanic eruptions, using 2,600 years' worth of records contained in ice cores from Antarctica. Stratospheric eruptions can launch sulfate particles more than 6 miles above Earth's surface, where they reflect sunlight and temporarily cool the planet.
Smaller, more frequent eruptions affect volcanic flare-ups
Eruption patterns in a New Zealand volcanic system reveal how the movement of magma rising through the crust leads to smaller, more frequent eruptions.
Using artificial intelligence to understand volcanic eruptions from tiny ash
Scientists led by Daigo Shoji from the Earth-Life Science Institute (Tokyo Institute of Technology) have shown that an artificial intelligence program called a Convolutional Neural Network can be trained to categorize volcanic ash particle shapes.
Repeating seismic events offer clues about Costa Rican volcanic eruptions
Repeating seismic events--events that have the same frequency content and waveform shapes--may offer a glimpse at the movement of magma and volcanic gases underneath Turrialba and Poas, two well-known active volcanoes in Costa Rica.
Detecting volcanic eruptions
Geophysicist Robin Matoza leads a case study of an eruption of Calbuco in Chile to evaluate data delivered by infrasound sensors
More Volcanic Eruptions News and Volcanic Eruptions Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.