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Fissure 22 of the lower East Rift Zone (USGS)

Why Scientists Are Actually Super-Excited About Hawaii's Massive Volcano Eruption

"It's an amazing opportunity." 

SCOTT WILSON AND SARAH KAPLAN, THE WASHINGTON POST
25 MAY 2018
 

Through the laze and vog, Kīlauea is giving up some of its secrets.

The volcano that began a new round of eruptions on May 3 is proving to be a bonanza for volcanologists, as it cracks apart at its base and blows periodically at its top to jettison lava and plumes of ash across much of an anxious Big Island.

 

Scientists are studying these oozing fissures, explosive eruptions and magma flow patterns as they happen, a rare opportunity for many of them who, without the real thing, are often left to model volcano behavior in distant laboratories.

What they are learning is not simply a boon for pure science, though it certainly is that.

Where the volcano cracks into fissures, how the magma tracks through the ground and what warning signs may exist that point to future eruptions will be used to better plan and protect Hawaiian communities in the future.

"It's an amazing opportunity to see in real time how this volcano is going to change," said Wendy Stovall, a volcanologist with the US Geological Survey who arrived on the Big Island last week.

"For some, this is going to mean a lifetime's work. And we owe it to the people who live here to make sure it is done."

Since Kīlauea began breaking apart at its base here in the Big Island's southeastern corner, walls of lava and dangerous gases have displaced thousands of Hawaiians and destroyed more than 45 homes and out buildings.

 

A geothermal power plant here, which provides about a quarter of the Big Island's electricity supply, has been threatened by the lava flows.

Company officials said this week that the plant, shuttered since the eruption began, has been made safe from any potential contact with lava.

The steam and gas venting from 22 fissures has cast a pinkish fog over much of the south, a phenomenon known as 'vog'.

Earlier this week, lava flows began to hit the Pacific Ocean, producing "laze," sending a mix of potentially toxic gas and tiny shards of glass into the atmosphere.

Stovall said a significant change during the past week is that the lava has been "losing its viscosity", meaning it is becoming hotter, slicker and faster-moving along the ground. As a result, it poses a larger threat to people and homes.

In addition, scientists have noted chemical similarities between the lava emerging from the fissures here in what is known as the "lower east rift area" and the magma at Kīlauea's peak.

That tells scientists magma is making its way down through the 4,000-foot (1.2 km) volcano - "like a straw is pulling it," Stovall said.

The result: less magma at the top to buoy up lava reservoirs. When those drop to a level that brings lava into contact with the water table, steam-driven explosions erupt at Kīlauea's summit, as has been happening with frequency in recent days.

lava explosion graph wapo

"What that means is we will continue to see activity," Stovall said. "But I can't say for how long."

Kīlauea has been erupting almost continuously for the past 25 years, but not nearly to the extent of this spring's activity. Scientists go back nearly a century to locate an eruption of Kīlauea equal in severity to the current one.

 

The volcano's liveliness has made it one of the most-studied in the world. Even before the ground opened up here, Kīlauea was like a patient in an intensive care unit, laden with monitoring equipment.

Every shiver of the ground, every exhalation of gas, every ripple of molten rock has been captured by an array of seismometers, tiltmeters, gas detectors, and airborne sensors.

In between eruptive episodes, researchers have canvassed the volcano's rocky slopes, uncovering evidence of ancient lava flows and deadly explosions.

"It's a chance to really have in-depth monitoring data on this kind of eruption where we know the volcano, we know what happened in the past," said Janine Krippner, a volcanologist at Concord University in West Virginia.

Krippner noted the recent explosions at the volcano's summit bear a strong resemblance to an event in 1924. It is almost as though the volcano is reproducing its own experiment, she said, helping researchers revisit and refine their models.

Researchers are particularly interested in the observations of Kīlauea's steam-powered "phreatic" eruptions, which occur when hot rock interacts with water in the ground. If the volcano's vent is blocked by falling rock, the resulting steam will build up pressure until it explodes.

 

The warning signs for these events are poorly understood, said Maarten de Moor, a researcher at Costa Rica's Volcanological and Seismological Observatory who has spent much of the past decade studying the subject.

"Oftentimes these phreatic systems are triggered by processes going on in the magma, which are then triggering processes going on in the hydrothermal system, which then erupt," he said. "It's another layer of complexity."

In 2014, 63 people were killed when a sudden steam-powered explosion surprised them near the summit of Japan's Mount Ontake. There had been no earthquakes or other precursory activity to warn authorities of the cataclysm to come.

But de Moor's research suggests studying the gases from volcanic vents in the hours and minutes leading up to an eruption might help scientists predict future phreatic events. The data from Kīlauea could bolster this work.

"I'm very interested ... to see if they're able to see distinct changes in the gas coming out," he said. "I expect great science from this event."

Volcano scientists are also captivated, like much of the general public, by the sheer spectacle of the eruption: visions of red-hot lava fountaining out of cracks in the Earth and towering columns of ash shooting 5 miles (8 km) into the sky.

"Any time a really dramatic event happens like this in the modern world, with live-streaming and photos, we get to see firsthand evidence of processes that geologists are just often combing through the rock record for," said Adam Kent, a geologist at Oregon State University.

Most of the volcanoes Kent studies, in the Cascade Arc along the Pacific coast, have not erupted in his lifetime. He must attempt to reconstruct ancient cataclysms from the lava flows they left behind, an archaeologist of destroyed landscapes and weathered rock.

What is happening at Kīlauea looks a lot like the wreckage left by Newberry Volcano, a shield volcano near Bend, Oregon, that last erupted in the year 690.

"You get an insight into what that would have been like if you'd been around a thousand years ago to watch it happen," Kent said.

But de Moor cautioned the lessons from Kīlauea do not apply universally.

Most places where the Earth erupts are at subduction zones, where one tectonic plate is thrust beneath another. That process melts the rock of the overriding plate, forming volcanic arcs like the "Ring of Fire" that surrounds the Pacific Ocean.

Because they are made of silica-rich continental rock, which makes a stickier lava, these volcanoes tend to form towering cones that erupt with a blast.

That process is entirely unconnected to what is happening in the Hawaiian Islands. There, new land is formed in the middle of open sea as the Pacific plate drifts over a plume of extra-hot material bubbling up from the mantle, what is known as a "hotspot."

The lava at these volcanoes, formed from molten oceanic crust, is runny and fluid. It oozes, rather than explodes. As the lava oozes into the ocean, as it has done with some regularity, it forms new land on the edge of the Big Island.

Krippner said it is a critical distinction. She has spent much of her time these past few weeks in interviews and on Twitter, quashing wild rumors about what Kīlauea might mean for the rest of the world.

No, there is not a connection between Hawaii and the Ring of Fire. No, we should not worry about catastrophic earthquakes or mega-tsunamis. No, fumes from Kīlauea will not reverse the course of climate change. Krippner gave a half chuckle, half sigh.

"You don't need the worst-case scenario to make volcanoes interesting," she said.

2018 © The Washington Post

This article was originally published by The Washington Post.

 

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