Jun 5, 2023

Volcanic Eruptions in Iceland Lead Scientists to Startling Discoveries Transcript

Volcanic Eruptions in Iceland Lead Scientists to Startling Discoveries Transcript
RevBlogTranscriptsGeldingadalurVolcanic Eruptions in Iceland Lead Scientists to Startling Discoveries Transcript

Bill Whitaker was there as lava flowed from a volcano in Iceland in 2021, covering the landscape in molten rock. He returned to see what scientists have learned from the eruption. Read the transcript here.

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Speaker 1 (00:01):

Months before the Geldingadalur volcano erupted in 2021, Iceland’s volcanologists knew it was coming. A subterranean serpent of magma was coiling through the depths, looking for a way out. As the magma stirred, it triggered tens of thousands of earthquakes. When the volcano finally blew, scientists scrambled for the equipment to record it. Many predicted a new seismic era for the land of fire and ice, and last summer, the same volcano exploded again. As we first reported in April, scientists have revealed some startling discoveries from the two eruptions, inching us closer to the day when eruptions will be forecast as we forecast rain. We went back to Iceland to see how the work was progressing.

The story will continue in a moment.

During the 2021 eruption, we saw chunks of molten rock the size of cars cartwheel into the air. Lava boiled up through nine vents as the earth unzipped, but it was number five, this one, that stole the show. We watched from a hilltop-

Look at that.

– with seismologist Kristin Jonsdottir as waves of lava poured down the valley. In the end, scientists calculated there was enough lava to fill an Olympic-sized swimming pool every four seconds. We wanted to see what it looked like now, so we flew back to the same hill.

Wow, this is remarkable.

Kristin Jonsdottir (01:44):

Completely changed.

Speaker 1 (01:45):

Completely changed. How much lava is out here?

Kristin Jonsdottir (01:49):

So the maximum thickness is about 100 meters, and it is the thickest by the crater.

Speaker 1 (01:55):

That’s a little more than 300 feet deep.

Kristin Jonsdottir (01:58):


Speaker 1 (01:59):

That’s incredible.

Lava had filled up the valley like a bathtub. The hills where Icelanders came for a closer look were gone. So was its tongue-twisting Icelandic name. Now we had to learn a new one.

Kristin Jonsdottir (02:15):

So the whole massive you see behind here is called [foreign language 00:02:20].

Speaker 1 (02:18):

[foreign language 00:02:23].

Kristin Jonsdottir (02:23):

Very good, excellent.

Speaker 1 (02:25):

That means beautiful valley mountain, a lot easier to pronounce. A new name for a new landscape. Jonsdottir, head of Earth Sciences at Iceland’s meteorological office, told us the 2021 eruptions were highly unusual. The quake storms that usually reach a crescendo before an eruption instead went silent. The tremors stopped. Only then did the volcano explode.

Kristin Jonsdottir (02:52):

So this was something we didn’t expect because before most eruptions we see an escalation in the process. So we see more and bigger earthquakes the closer we come to an eruption.

Speaker 1 (03:04):

And what did you find this time?

Kristin Jonsdottir (03:05):

Everything got quiet and we thought, okay, maybe this is it. We’re not going to see an eruption this time. But we were wrong.

Speaker 1 (03:15):

The magma bomb lasted six months. Then this past August, the volcano exploded again. This time scientists weren’t fooled. When the earthquakes stopped, they ran tests that showed the volcano wasn’t sleeping, rocks were still moving, gas escaping. Scientists called an audible and warned the volcano would likely blow within 24 hours. They were right.

Today the crater is still cooling. It’s quiet for now.

Look at that.

Kristin Jonsdottir (03:52):


Speaker 1 (03:53):

Remember when we flew around the plume, the fountain?

Kristin Jonsdottir (03:57):

I remember I didn’t feel as safe at that point.

Speaker 1 (04:01):

In 2021, we had to veer away from the crater. It was too dangerous to get any closer.

Kristin Jonsdottir (04:08):

This feels much safer.

Speaker 1 (04:09):

So do you think the eruption here is completely over?

Kristin Jonsdottir (04:12):

Right now we are not seeing anything, but we also know that this can happen quite quickly. The warning time we have is not necessarily going to be many weeks, but maybe just a couple of days.

Speaker 1 (04:24):

The lava field is like a record of the eruption, so we set off at the crack of dawn. That’s an hour before noon when the winter sun rises this far north. Soon we ran out of road, then we ran out of steam. Our trucks had 42-inch tires, but that was no match for snow that was as fine as sugar.

Finally, we arrived to find a vast sea of volcanic rock just six months old. Geophysicist Freysteinn Sigmundsson from the University of Iceland gave us a tour.

It is freezing out here, but this is warm.

Freysteinn Sigmundsson (05:07):

Yeah, feel it. This is the heat of the lava.

Speaker 1 (05:10):

Look at that.

Freysteinn Sigmundsson told us if we dug just 20 feet below where we were standing, we’d find molten rocks still at a scorching 1800 degrees.

Freysteinn Sigmundsson (05:22):

The heat is still coming out and it will be for a number of years.

Speaker 1 (05:27):

But even with this, the temperatures here, it’s going to take years for this to cool down?

Freysteinn Sigmundsson (05:31):

Yes. Yes. It will.

Speaker 1 (05:33):

It’s that hot?

Freysteinn Sigmundsson (05:34):

It is that hot and that thick.

Speaker 1 (05:37):


Sigmundsson and told us these eruptions had spewed out. The largest mix of lavas ever recorded. They cooled in different shapes. Some were as smooth as sidewalk, gnarled like roots, or stretched taut like rope.

Freysteinn Sigmundsson (05:54):

Yeah, we call them lava cables. I would say this is maybe one of the best place on planet Earth to see this lava cables here.

Speaker 1 (06:01):

Freysteinn Sigmundsson told us he now wants to find out if their most recent finding, a seismic decline before an eruption, might apply to similar volcanoes in Japan, Russia, or the United States. It’s urgent to do so, he told us, as warmer temperatures melt the glaciers that sit like a pressurized lid on many of the world’s most volatile volcanoes.

So the retreating glaciers have an effect on the volcanoes?

Freysteinn Sigmundsson (06:29):

Yes. Retreating glaciers can increase the possibility of eruptions.

Speaker 1 (06:33):

How so?

Freysteinn Sigmundsson (06:34):

The glaciers, they are pushing down on the earth. There’s a force. So if the glaciers are moving, it change the force. Already, the retreat of glaciers in Iceland, they are causing a lot more of new magma being formed under Iceland than normally.

Speaker 1 (06:51):

With this new magma came new discoveries. In 2021, Ed Marshall, a Texas trained geophysicist, showed us the lava wall when it was a mere 30 feet high. We watched as he scooped the molten lava, flash cooling it in water. This trip, we met Marshall in his lab at the University of Iceland to see what he had found.

Ed Marshall (07:16):

We have an instrument called an ICPOES.

Speaker 1 (07:19):

And that stands for?

Ed Marshall (07:20):

It’s an Inductively Coupled Plasma Optical Emissions Spectrometer.

Speaker 1 (07:25):


The impossibly named machine is able to measure with pinpoint accuracy the chemical composition of the rock. But Marshall wasn’t expecting what they found next: crystals.

So what did you learn from these?

Ed Marshall (07:42):

Well, we learned that they’re coming from nine miles deep below the volcano.

Speaker 1 (07:47):

Nine miles down.

Ed Marshall (07:48):

Mm-hmm. It’s actually coming from a part of the earth that we don’t normally get to sample, the boundary sheet between the crust and mantle.

Speaker 1 (07:56):

The magma had come straight up like an express elevator from deep in the mantle, opening a rare window into the Earth’s deep plumbing. Geophysicist Ed Marshall showed us samples of the different lavas he’s collected.

Ed Marshall (08:11):

So here we have a different kind of lava called a pahoehoe lava.

Speaker 1 (08:15):

It’s much smoother.

Ed Marshall (08:16):


Speaker 1 (08:17):

When the lavas were still red-hot, they flowed at different speeds. Some oozed out of the volcano. Others exploded, moving as fast as 10 miles an hour.

Ed Marshall (08:28):

It’s important to figure it out because they have different hazard potential. If you’re worried about your town being covered by lava-

Speaker 1 (08:35):

Be more worried about this one.

Ed Marshall (08:37):


Speaker 1 (08:38):

Like so many other volcanologists who’d rushed to the eruption site in 2021, this self-described lab rat told us he was awed by the sheer power on display.

Ed Marshall (08:50):

You have work to do it, but there are times when you just sit there and stare at the volcano. It’s just so much grander than you. It’s kind of this almost divine kind of presence.

Speaker 1 (09:03):

Every volcano, as we learned, has its own personality. If Fagradalsfjall had elements of the divine, others were not as beatific. Take Grímsvötn, routinely described as cranky. Overdue for an eruption, Grímsvötn is hidden beneath a glacier, making it almost impossible to monitor. So seismologist Kristin Jonsdottir and her European partners tried something new: burying a coil of fiber optic cables in the ice cap.

Kristin Jonsdottir (09:35):

So the cable we used was only four millimeters thick and so thin, they’re actually thinner than a human hair. Yeah, it’s a bit funny. It’s like you’re trenching a very 13 kilometer long hair along a volcano.

Speaker 1 (09:53):

They devised a makeshift trenching sled to bury the cables to try to pick up volcanic tremors. It worked. Where regular seismometers barely registered a pulse, the fiber optic cable showed Grímsvötn was grumbling irritably inside its icy tomb. Jonsdottir told us it could be a game changer.

And you found how many more earthquakes?

Kristin Jonsdottir (10:17):

100 times more.

Speaker 1 (10:19):

Found with this fiber?

Kristin Jonsdottir (10:21):


Speaker 1 (10:21):

Did you find something in the pattern here that you could say, “Ah, if we see this indicates that an eruption is going to happen”?

Kristin Jonsdottir (10:29):

So the potential here is really to be able to understand the volcanoes and the plumbing system. Just being able to see in this high definition picture that we were not able to see before.

Speaker 1 (10:40):

And this is just standard cable? The cable that we use for bringing television into our homes.

Kristin Jonsdottir (10:46):


Speaker 1 (10:47):

But Iceland is one of the few places in the world to actively watch its volcanoes. The lack of monitoring elsewhere can sometimes spell disaster. Like the 2018 bang out of the blue in Indonesia that killed 400 people. Cornell geophysicist Matthew Pritchard told us they’ve got to do a better job.

Matthew Pritchard (11:09):

So there are about 600 that have erupted in historic times the last 500 years, and of those only about 35% have continuous monitoring at them.

Speaker 1 (11:19):

What’s the problem?

Matthew Pritchard (11:20):

Well, it’s expense. It’s maintaining these instruments. Again, once a volcano stops erupting, should we continue to monitor it or has it gone to sleep for another couple hundred years? So it’s all a question of priorities. It’s a question of resources.

Speaker 1 (11:33):

But Pritchard told us there’s a solution on hand: spying on volcanoes from space. He’s spearheading an effort to establish a satellite network that will continuously monitor the world’s most restless volcanoes. Take Mauna Loa in Hawaii. This past November, it tore open the earth after 38 years of slumber. On the ground, magma forced its way through deep layers of rock until it cracked the earth’s surface. From space, it looked like this.

Matthew Pritchard (12:06):

So each one of these contours here means 25 centimeters of ground motion. So on this side of the rift, it moved this way about 25 centimeters. And then this side, the opposite direction. And so this is evidence of the magma coming up through the system and pushing the ground to the side as it was coming out to erupt.

Speaker 1 (12:24):

And all of this captured by satellite?

Matthew Pritchard (12:26):


Speaker 1 (12:27):

The satellite can detect what level of movement on the surface of the earth?

Matthew Pritchard (12:32):

Best case scenario, a few millimeters.

Speaker 1 (12:34):

A few millimeters?

Matthew Pritchard (12:35):

That’s right.

Speaker 1 (12:36):

From space?

Matthew Pritchard (12:36):

That’s right.

Speaker 1 (12:37):

Cornell’s Pritchard told us the new gold standard would be to combine ground sensors with satellite images to help detect eruptions. Earlier next year, a new satellite will be launched that will use radar waves capable of penetrating dense jungle or snow and seeing deeper underground than ever before. But as technology turbocharges the ability of volcanologists to forecast eruptions, we were reminded that the Earth has been at this far longer than scientists have been collecting data and that, one told us, keeps you humble.

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