Undersea volcano gave off signals before eruption in 2011

Jun 10, 2012 By Mark Floyd
The manipulator arm of the Jason remotely operated vehicle (upper left) prepares to sample the new lava flow that was erupted in 2011 on the seafloor at Axial Seamount. (Photo credit: Bill Chadwick, Oregon State University, Copyright Woods Hole Oceanographic Institution)

(Phys.org) -- A team of scientists that last year created waves by correctly forecasting the 2011 eruption of Axial Seamount years in advance now says that the undersea volcano located some 250 miles off the Oregon coast gave off clear signals hours before its impending eruption.

The researchers' documentation of inflation of the undersea volcano from gradual magma intrusion over a period of years led to the long-term eruption forecast. But new analyses using data from underwater also show an abrupt spike in seismic energy about 2.6 hours before the eruption started, which the scientists say could lead to short-term forecasting of undersea volcanoes in the future.

They also say that Axial could erupt again – as soon as 2018 – based on the cyclic pattern of ground deformation measurements from bottom pressure recorders.

Results of the research, which was funded by the National Science Foundation, the National Oceanic and Atmospheric Administration, and the Monterey Bay Aquarium Research Institute (MBARI), are being published this week in three separate articles in the journal Nature Geoscience.

Bill Chadwick, an Oregon State University geologist and lead author on one of the papers, said the link between seismicity, seafloor deformation and the intrusion of magma has never been demonstrated at a submarine volcano, and the multiple methods of observation provide fascinating new insights.

"Axial Seamount is unique in that it is one of the few places in the world where a long-term monitoring record exists at an – and we can now make sense of its patterns," said Chadwick, who works out of Oregon State's Hatfield Marine Science Center in Newport, Ore. "We've been studying the site for years and the uplift of the seafloor has been gradual and steady beginning in about 2000, two years after it last erupted.

"But the rate of inflation from magma went from gradual to rapid about 4-5 months before the eruption," added Chadwick. "It expanded at roughly triple the rate, giving a clue that the next eruption was coming."

A spider crab inspects an ocean-bottom hydrophone (OBH) as it sits on the seafloor at Axial Seamount before the 2011 eruption. The OBH is a monitoring instrument designed to detect undersea earthquakes. The chain is connected to flotation above the view of the photo. (Image credit: Bill Chadwick, Oregon State University)

Bob Dziak, an Oregon State University marine geologist, had previously deployed hydrophones on Axial that monitor sound for seismic activity. During a four-year period prior to the 2011 eruption, there was a gradual buildup in the number of small earthquakes (roughly magnitude 2.0), but little increase in the overall "seismic energy" resulting from those earthquakes.

That began to change a few hours before the April 6, 2011, eruption, said Dziak, who also is lead author on one of the Nature Geoscience articles.

"The hydrophones picked up the signal of literally thousands of small earthquakes within a few minutes, which we traced to magma rising from within the volcano and breaking through the crust," Dziak said. "As the magma ascends, it forces its way through cracks and creates a burst of earthquake activity that intensifies as it gets closer to the surface.

"Using seismic analysis, we were able to clearly see how the magma ascends within the volcano about two hours before the eruption," Dziak said. "Whether the seismic energy signal preceding the eruption is unique to Axial or may be replicated at other volcanoes isn't yet clear – but it gives scientists an excellent base from which to begin."

The researchers also used a one-of-a-kind robotic submersible to bounce sound waves off the seafloor from an altitude of 50 meters, mapping the topography of Axial Seamount both before and after the 2011 eruption at a one-meter horizontal resolution. These before-and-after surveys allowed geologists to clearly distinguish the 2011 from the many previous flows in the area.

MBARI researchers used three kinds of sonar to map the seafloor around Axial, and the detailed images show lava flows as thin as eight inches, and as thick as 450 feet.

A “snowblower” hydrothermal vent spews hot water and white bits of bacterial mat that are blooming in the chemical-rich hot-spring water, showing that the lava flow that was erupted in 2011 at Axial Seamount is still cooling. (Image credit: Bill Chadwick, Oregon State University, Copyright Woods Hole Oceanographic Institution)

"These autonomous underwater vehicle-generated maps allowed us, for the first time, to comprehensively map the thickness and extent of lava flows from a deep-ocean submarine in high resolution," said David Caress, an MBARI engineer and lead author on one of the Nature Geoscience articles. "These new observations allow us to unambiguously differentiate between old and new lava flows, locate fissures from which these flows emerged, and identify fine-scale features formed as the lava flowed and cooled."

The researchers also used shipboard sonar data to map a second, thicker lava flow about 30 kilometers south of the main flow – also a likely result of the 2011 eruption.

Knowing the events leading up to the eruption – and the extent of the lava flows – is important because over the next few years researchers will be installing many new instruments and underwater cables around Axial Seamount as part of the Ocean Observatories Initiative. These new instruments will greatly increase scientists' ability to monitor the ocean and seafloor off of the Pacific Northwest.

"Now that we know some of the long-term and short-term signals that precede eruptions at Axial, we can monitor the seamount for accelerated seismicity and inflation," said OSU's Dziak. "The entire suite of instruments will be deployed as part of the Ocean Observatories Initiative in the next few years – including new sensors, samplers and cameras – and next time they will be able to catch the volcano in the act."

The scientists also observed and documented newly formed hydrothermal vents with associated biological activity, Chadwick said.

"We saw snowblower vents that were spewing out nutrients so fast that the microbes were going crazy," he pointed out. "Combining these biological observations with our knowledge of the ground deformation, seismicity and lava distribution from the 2011 will further help us connect underwater volcanic activity with the life it supports."

Scientists from Columbia University, the University of Washington, North Carolina State University, and the University of California at Santa Cruz also participated in the project and were co-authors on the Nature Geoscience articles.

Explore further: TRMM satellite sees Tropical Storm Phanfone fragmented

More information: DOI: 10.1038/ngeo1464 , DOI: 10.1038/ngeo1490 , DOI: 10.1038/ngeo1496

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Ophelia
1 / 5 (5) Jun 10, 2012
"A team of scientists that last year ...."
Ok. Let's see. Last year was ... 2011, right?

"created waves by correctly forecasting the 2011 eruption of Axial Seamount ... "
Ok. Predicted in 2011 an eruption in 2011.

"years in advance ..."
Huh????

"now says that the undersea volcano located some 250 miles off the Oregon coast gave off clear signals hours before its impending eruption."

I'm ready to apply for a 4th grade English teaching position. I know where I'll be getting samples for how NOT to write.
rpichie2
4 / 5 (8) Jun 10, 2012
"years in advance ..."
Huh????
"I'm ready to apply for a 4th grade English teaching position. I know where I'll be getting samples for how NOT to write."
---
1. Prediction made years in advance.
2. Success of prediction achieved in 2011.

Not a very difficult concept.
Lex Talonis
3.7 / 5 (6) Jun 10, 2012
I predict using biblical technology that satan shall be let loosed from the fiery pit and shall walk the earth and rule his world....

NotParker
1.9 / 5 (9) Jun 10, 2012
There are 10s of thousands of undersea volcanoes warming the ocean and emitting CO2.

http://www.upi.co...8321364/
_ilbud
3.4 / 5 (5) Jun 10, 2012
The amount of stuff NotParker is surprised by is amazing. It's almost as though he has no clue whatsoever about his hobbyhorse. If I was as ignorant as him I'd maybe try to find out some facts before spouting ignorant stupidity all over the net.
Ophelia
3 / 5 (2) Jun 10, 2012
@rpihie2:

Pray tell exactly when this "mystery" prediction was made "years in advance"? Certainly nothing is mentioned in the article that I could see.

It is a poorly written sentence that is very confusing - which is very typical of this site. I have to stop and reread more sentences on this site than any other I visit.

"Waves were created by the 2011 eruption of Axial Seamount when the ???? prediction by a team of scientists came true. That same team now reports that the undersea volcano located some 250 miles off the Oregon coast gave off clear signals hours before its impending 2011 eruption."
kevinrtrs
1 / 5 (7) Jun 12, 2012
I tend to agree with Ophelia on this article - it's as clear as mud where/when this prediction was made "years in advance". The article should be revised.

As for some off-topic remark by Lex Talonis
I predict using biblical technology that satan shall be let loosed from the fiery pit and shall walk the earth and rule his world.
Though I know his intention is to joke, I'd like to set the record straight since he's using the "biblical technology" incorrectly:
Satan will be set free from the abyss[which is NOT the fiery hell] and be allowed to deceive the nations who did not believe. He'll gather a mighty army from far and sunder for the battle of Armageddon against the city of Jerusalem - and be totally annihilated. Then thrown into the lake of fire.
But of course that's totally off-topic.
jsdarkdestruction
5 / 5 (3) Jun 12, 2012
and complete bullshit.......