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Wednesday, November 06, 2024

Something Weird Happened 15 Minutes Before the Giant Tonga Eruption of 2022

A previously overlooked seismic signal portended the gargantuan volcanic eruption.
Published November 5, 2024 
A satellite image of the Tonga eruption.
Images: NASA Earth Observatory / Joshua Stevens / Lauren Dauphin / CALIPSO data from NASA/CNES, MODIS and VIIRS data from NASA EOSDIS LANCE and GIBS/Worldview and the Suomi National Polar-orbiting Partnership, and GOES imagery courtesy of NOAA and the National Environmental Satellite, Data, and Information Service (NESDIS)

Two years ago, the Hunga Tonga-Hunga Ha’apai volcano blew its top, destroying the island of the same name, forcing mass evacuations, covering Tonga in ash, and causing several deaths. Predicting these sorts of natural disasters are exceedingly difficult, but a surprising new finding suggests some volcanoes give off a clue in the minutes preceding a cataclysmic eruption.

According to a team of researchers that reviewed some overlooked data from that data, the huge volcanic eruption that rocked the Pacific Ocean in 2022 was preceded by a seismic wave that shot across Earth’s surface. The data was collected by faraway seismometers, but the recent team posits that even those distant signals can help people prepare for future surprise eruptions.

Early warning systems for natural disasters—earthquakes, eruptions and tsunamis, as well as more predictable events like hurricanes, tornadoes, and typhoons—save lives. Any amount of notice is better than none, as even critical minutes of warning can make the difference between life and death.

“Early warnings are very important for disaster mitigation,” said study co-author Mie Ichihara, a volcanologist at the University of Tokyo, in an American Geophysical Union release. “Island volcanoes can generate tsunamis, which are a significant hazard.”

The team inspected seismometer data from stations in Fiji and Futuna—over 466 miles (750 kilometers) from the eruption. In that data, the researchers found a certain kind of surface-traveling seismic wave—called a Rayleigh wave—that emanated from the direction of the cataclysmic eruption about 15 minutes before the event itself. The Rayleigh wave was imperceptible to humans, but the seismometers had no problem picking it up.

“Referring to other seismic signals and satellite images, we concluded that the Rayleigh wave was the most significant eruption precursor with no apparent surface activity,” the researchers wrote in their work, published Monday in Geophysical Research Letters. “Including our findings and results of previous studies, we propose a scenario of the beginning of the caldera-forming eruption.”

The record-breaking eruption occurred on January 15, 2022. The eruption’s 36-mile-high (58-kilometer-high) volcanic plume was the largest ever recorded, and reached Earth’s mesosphere in just half an hour. The previous record-holder was the huge 1991 eruption of Mount Pinatubo in the Philippines.

As the team notes, the Hunga Tonga-Hunga Ha‘apai eruption was not preceded by any “apparent surface activity.” Consequently, the Rayleigh wave was the main indicator of the imminent destruction.

“When a usual earthquake occurs, seismic waves including the Rayleigh wave are instantaneously used to estimate the source parameters,” such as the epicenter, depth, magnitude, and mechanism, Ichihara told Gizmodo in an email. “Then, the source parameters are used to disseminate Tsunami early warning. However, there is no existing infrastructure to use the Rayleigh wave from an eruption precursor like the one identified in our article, though we believe it useful.”

“At the time of the eruption, we didn’t think of using this kind of analysis in real-time.”

In their paper, the researchers suggest that a fracture in the oceanic crust beneath the volcano’s caldera wall released the seismic wave detected in Fiji and Futuna. Then, magma from beneath the crust and ocean water above it poured into the volcano’s magma chamber beneath the surface, which caused the land above to collapse and kick off the eruption.

The team suggests that analyzing data from seismic stations located even hundreds of miles from an eruption can reveal the event before its worst impacts occur. “At the time of the eruption, we didn’t think of using this kind of analysis in real-time,” Ichihara said. “But maybe the next time that there is a significant eruption underwater, local observatories can recognize it from their data.”



Monday, January 17, 2022

Tonga volcano: distress signal detected in low-lying islands after eruption, as first death reported

Regular contact with Tonga may not resume for weeks after confirmation the communications cable was cut in at least one place
Hunga Tonga-Hunga Ha’apai volcano erupted on Saturday, triggering a tsunami warning for several South Pacific island nations. 
Photograph: New Zealand High Commission/ZUMA Press Wire Service/REX/Shutterstock

Tess McClure
@tessairini
Tue 18 Jan 2022 00.13 GMT

A distress signal has been detected in an isolated, low-lying group of Tongan islands after Saturday’s huge volcanic eruption, even as most external communications remain down, and diaspora families anxiously await news.

Reuters reports that the UN detected the distress signal on Monday, prompting particular concern for the inhabitants of Fonoi and Mango. According to the Tonga government, 36 people live on Mango and 69 on Fonoi.

The news comes as most communication between Tonga and the outside world is still cut off, after the Pacific nation’s main communication cable was broken by the eruption of Hunga Tonga-Hunga Ha’apai volcano and subsequent tsunami.


Tonga volcano: a visual guide to the eruption and its aftermath

Tongans around the world may be forced to wait weeks for regular contact to resume, after testing confirmed that the cable connecting the islands to the outside world was cut in at least one place.

A spokesperson for Southern Cross Cable, which operates other undersea cable networks across the region, said that testing by Fintel and Tonga Cable on Sunday afternoon “seems to confirm a likely cable break around 37km offshore from Tonga”.

The offshore nature of the break means it is more difficult and time consuming to repair, with a specialist cable repair ship being dispatched from Papua New Guinea. The spokesperson said reports indicated that “while timing is currently unconfirmed it is likely to be one to two weeks before they have repaired the cable, conditions willing”.

There have been no official confirmations of casualties from Tongan authorities, but the family of Angela Glover, a British woman living in Tonga who went missing in the tsunami, reported on Monday that her body had been found.

Images from Australian and New Zealand defence force surveillance flights that travelled to the islands on Monday have not been released. But UN analysis of satellite imagery from the island of Nomuku found that almost all visible structures were covered with ash, and about 40% of visible structures were damaged.


‘Not knowing is heartbreaking’: sleepless nights among Tongan diaspora after contact with country cut off

New Zealand prime minister Jacinda Ardern said on Monday that boulders and boats had washed ashore on Tongatapu, Tonga’s largest island, about 65km south of the volcano.

“Seeing some of those waves come in and peeling back fencelines and structures, you can see the force of those surges,” she said. “Everyone just wants to establish how wide scale that impact has been … we want to be in Tonga and on the ground as soon as we are possibly able to be.”

The United Nations Office for Coordination of Humanitarian Affairs said in a briefing on Monday there was significant infrastructural damage around the main island of Tongatapu. “We are particularly concerned about two small low-lying islands – Mango and Fonoi – following New Zealand and Australian surveillance flights confirming substantial property damage,” they said.

Distress beacon from islands near Tonga eruption site detected

A map provided by the European Commission's Directorate-General for European Civil Protection and Humanitarian Aid Operations shows the extent of Saturday's Tonga volcanic eruption. Map courtesy of ECHO


Jan. 17 (UPI) -- A distress signal emanating from a pair of isolated, low-lying islands near Tonga has been detected in the wake of this weekend's undersea volcano eruption, United Nations officials said Monday.

The UN Office for the Coordination of Humanitarian Affairs said the distress beacon is coming from the Ha'apai Group of islands, situated 45 miles northeast of the main Tongan island of Tongatapu, where concerns were mounting about the welfare of the small islands of Mango and Fonoi.

The two islands lie just a few miles to the northeast of Saturday's eruption site in the South Pacific.

The blast covered the Tongan capital of Nuku'alofa in ash and dust and triggered tsunami waves in several Pacific Ocean nations, particularly Tonga, Fiji, Samoa, Vanuatu, Solomon Islands, the United States, Mexico, Peru and Chile.

Communications in the South Pacific remained disrupted Monday, two days after the eruption.

Two people had been reported missing in Tonga. Family members of one of the missing persons, British national Angela Glover, said her body was recovered Monday after she was swept away by the tsunami wave, Sky News reported.

Two others were reported killed in Peru, while two people were injured during evacuations in Japan, local authorities said.

In investigating the distress beacon from the islands of Mango and Fonoi, OCHA said Australia carried out a surveillance flight Monday and reported substantial property damage on the beaches.

The Tongan Maritime Force has also deployed to the Ha'apai Group of islands.



Tonga: First reconnaissance flights surveil aftermath of volcanic eruption

Communication with the Pacific island is still spotty after a massive volcanic eruption spewed ash into the atmosphere. The eruption triggered a tsunami that flooded coastlines from Japan to the United States.


TONGA VOLCANO ERUPTION SENDS TSUNAMI WAVES ACROSS PACIFIC
Volcano erupts off of Tonga
A volcano near the island nation of Tonga erupted on Saturday, sending tsunami waves across the Pacific. The massive eruption has severely hampered international communication with the island.
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New Zealand said Monday it was able to send a surveillance plane to assess the damage caused by the Hunga-Tonga-Hunga-Ha'apai underwater volcano.

The volcano erupted off the coast of Tonga on Saturday evening, sending a plume of ash, steam, and gas rising high into the atmosphere. The roar from the eruption was reportedly heard 10,000 kilometers (6,000 miles) away in Alaska.

After a tsunami triggered by the eruption that hit the Pacific island, officials downgraded the threat of further tsunamis on Sunday.

At least one person on Tonga — a British woman — is reported to have died.



A volcano near Tonga erupted in the Pacific on Saturday, triggering a tsunami
What is the latest?

Australia also sent a reconnaissance flight on Monday to assess damage in Tonga.

Australia's Minister for the Pacific Zed Seselja said initial reports suggested no mass casualties from the eruption. However, Australian police had visited beaches and reported significant damage with "houses thrown around."

"We know there is some significant damage, and know there is significant damage to resorts," Seselja said in a radio interview. He added that Tonga's airport appeared to be in good condition.

Tonga's deputy head of mission in Australia, Curtis Tu'ihalangingie, said the flights were expected to return on Monday evening.

Tonga is concerned about the risk of COVID-19 reaching the island through aid deliveries, as it is currently COVID-free.

"We don't want to bring in another wave — a tsunami of COVID-19," Tu'ihalangingie told Reuters.

Tu'ihalangingie added that it is likely that foreign personnel would not be allowed to disembark aircraft and any aid delivered would need to be quarantined.

Officials were also worried about the fate of some of the many isolated, low-lying islands nearby, especially after a distress signal was detected on one.

A tsunami flooded parking lot at a harbor in Santa Cruz, California on Saturday
'Significant' damage to Tonga capital


A full assessment was not possible as of Sunday, as the eruption knocked out the internet and disrupted communication with the island. Tonga receives its internet via an undersea cable from Fiji.

The company that owns the fiber-optic cable that connects Tonga to the rest of the world said it likely was severed in the eruption and repairs could take weeks, the Associated Press reported.

However, New Zealand Prime Minister Jacinda Ardern said at a press briefing on Sunday that Tonga's capital, Nuku'alofa, suffered "significant" damage.

"The tsunami has had a significant impact on the foreshore on the northern side of Nuku'alofa with boats and large boulders washed ashore," she said after managing to contact the New Zealand embassy in Tonga.

"Nuku'alofa is covered in a thick film of volcanic dust but otherwise conditions are calm and stable," the prime minister added.

There were no official reports of injuries or deaths in Tonga, she said, while cautioning that authorities were yet to contact some coastal areas and smaller islands.

"Communication with Tonga remains very limited. And I know that is causing a huge amount of anxiety for the Tongan community here," the prime minister said.

The thick ash cloud 63,000 feet (19,000 meters) above Tonga had previously prevented military surveillance flights.

'One of the most explosive eruptions in the 21st century'


Experts expressed concern about the sheer size of the eruption and are on the lookout for potentially further volcanic activity.

"It was a remarkable eruption. It was extremely explosive. We're sort of thinking it's one of the most explosive eruptions in the 21st century at the moment," Shane Cronin, professor of volcanology at the University of Auckland in New Zealand, told DW.

"These very large ones at this volcano happen about once every 900 years, but they seem to have a series of events, and so this may be the first in a series of eruptions," he added.

In terms of damage, the expert said the main concerns at the moment are about how hard the tsunami hit, as well as the level of ash that has fallen on the island.

"So far, what we've seen has been tsunami damage, and most of what we've seen has been from Tongatapu — the main inhabited island of Tonga where the capital Nuku'alofa is," Cronin said.

"What we're concerned about is some of the low-lying islands, which are actually very close to Hunga-Ha'apai - Nomuka and the islands of the Ha'apai group. These islands have potentially a lot of low-lying areas that were affected by tsunami waves," he added.

"At the moment, the ashfall that has gone on to Tongatapu hasn't been that large yet, but the eruption column actually spread in a way that it probably would have [and possibly still will] put more ash onto the central part of the Tongan island group," the volcanologist said.

"What we're waiting to find out now is that what kinds of impacts there have been, what kind of help people need."

International support


Besides New Zealand, other countries have expressed concern for Tonga and offered help.

An Australian government spokesperson said initial assessments were still underway, but the country was ready to provide support to Tonga if requested.

US Secretary of State Antony Blinken also expressed concern, adding that the US "stands prepared to provide support to our Pacific neighbors."

The lack of COVID-19 outbreaks on the island of 105,000, is another element for international aid efforts to take into account.

New Zealand has assured that its military staff was all fully vaccinated and willing to follow any protocols established by the island nation.
Tsunami threat downgraded

The tsunami threat around the Pacific basin from the powerful underwater volcano eruption off the coast of Tonga began to recede on Sunday, the Pacific Tsunami Warning Center said.

Authorities at "impacted coastal areas should monitor... to determine when it is safe to resume normal activities," the center said.

The seismic force sent powerful waves crashing into coastlines from Japan to the United States.

The US National Weather Service in American Samoa canceled its tsunami advisory on Monday, but officials urged caution when entering the water.

In Peru, two women died in Lambayeque due to "anomalous waves."

ab, sdi, adi/wmr, rs (AFP, AP, Reuters)


The ash cloud from the erupting volcano seen from a US satellite

DW RECOMMENDS

Tonga volcano eruption sends tsunami waves across Pacific

A volcanic eruption in Tonga has sent tsunami waves that have hit coastlines as far as Japan and New Zealand and flooded the Tongan capital of Nuku'alofa.

Flights sent to assess Tonga damage after volcanic eruption

By NICK PERRY

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In this photo provided by the New Zealand Defense Force, an Orion aircraft is prepared at a base in Auckland, New Zealand, Monday, Jan. 17, 2022, before flying to assist the Tonga government after the eruption of an undersea volcano. (NZDF via AP)


WELLINGTON, New Zealand (AP) — New Zealand and Australia were able to send military surveillance flights to Tonga on Monday to assess the damage a huge undersea volcanic eruption left in the Pacific island nation.

A towering ash cloud since Saturday’s eruption had prevented earlier flights. New Zealand hopes to send essential supplies, including much-needed drinking water, on a military transport plane Tuesday.

A British woman who was missing has been found dead, her family said, in the first reported fatality on Tonga.

The brother of Angela Glover, who ran an animal rescue center, said the 50-year-old died after being swept away by a wave.

Nick Eleini said his sister’s body had been found and that her husband survived.

“I understand that this terrible accident came about as they tried to rescue their dogs,” Eleini told Sky News.

He said it had been his sister’s life dream” to live in the South Pacific and “she loved her life there.”

Communications with Tonga remained extremely limited. The company that owns the single underwater fiber-optic cable that connects the island nation to the rest of the world said it likely was severed in the eruption and repairs could take weeks.

The loss of the cable leaves most Tongans unable to use the internet or make phone calls abroad. Those that have managed to get messages out described their country as looking like a moonscape as they began cleaning up from the tsunami waves and volcanic ash fall.

Tsunami waves of about 80 centimeters (2.7 feet) crashed into Tonga’s shoreline, and New Zealand Prime Minister Jacinda Ardern described damage to boats and shops on Tonga’s shoreline. The waves crossed the Pacific, drowning two people in Peru and causing minor damage from New Zealand to Santa Cruz, California.

Scientists said they didn’t think the eruption would have a significant impact on the Earth’s climate.

Huge volcanic eruptions can sometimes cause temporary global cooling as sulfur dioxide is pumped into the stratosphere. But in the case of the Tonga eruption, initial satellite measurements indicated the amount of sulfur dioxide released would only have a tiny effect of perhaps 0.01 Celsius (0.02 Fahrenheit) global average cooling, said Alan Robock, a professor at Rutgers University.

Satellite images showed the spectacular undersea eruption Saturday evening, with a plume of ash, steam and gas rising like a giant mushroom above the South Pacific waters.

A sonic boom could be heard as far away as Alaska and sent pressure shockwaves around the planet twice, altering atmospheric pressure that may have briefly helped clear out the fog in Seattle, according to the National Weather Service. Large waves were detected as far away as the Caribbean due to pressure changes generated by the eruption.

Samiuela Fonua, who chairs the board at Tonga Cable Ltd. which owns the single cable that connects Tonga to the outside world via Fiji, said the cable appeared to have been severed about 10 to 15 minutes after the eruption. He said the cable lies atop and within coral reef, which can be sharp.

Fonua said a ship would need to pull up the cable to assess the damage and then crews would need to fix it. A single break might take a week to repair, he said, while multiple breaks could take up to three weeks. He added that it was unclear yet when it would be safe for a ship to venture near the undersea volcano to undertake the work.

A second undersea cable that connects the islands within Tonga also appeared to have been severed, Fonua said. However, a local phone network was working, allowing Tongans to call each other. But he said the lingering ash cloud was continuing to make even satellite phone calls abroad difficult.

He said Tonga, home to 105,000 people, had been in discussions with New Zealand about getting a second international fiber-optic cable to ensure a more robust network but the nation’s isolated location made any long-term solution difficult.

The cable also broke three years ago, possibly due to a ship dragging an anchor. At first Tongans had no access to the internet but then some limited access was restored using satellites until the cable was repaired.

Ardern said the capital, Nuku’alofa, was covered in a thick film of volcanic dust, contaminating water supplies and making fresh water a vital need.

Aid agencies said thick ash and smoke had prompted authorities to ask people to wear masks and drink bottled water.

In a video posted on Facebook, Nightingale Filihia was sheltering at her family’s home from a rain of volcanic ash and tiny pieces of rock that turned the sky pitch black.

“It’s really bad. They told us to stay indoors and cover our doors and windows because it’s dangerous,” she said. “I felt sorry for the people. Everyone just froze when the explosion happened. We rushed home.” Outside the house, people were seen carrying umbrellas for protection.

One complicating factor to any international aid effort is that Tonga has so far managed to avoid any outbreaks of COVID-19. Ardern said New Zealand’s military staff were all fully vaccinated and willing to follow any protocols established by Tonga.

Dave Snider, the tsunami warning coordinator for the National Tsunami Warning Center in Palmer, Alaska, said it was very unusual for a volcanic eruption to affect an entire ocean basin, and the spectacle was both “humbling and scary.”

The U.S. Geological Survey estimated the eruption caused the equivalent of a magnitude 5.8 earthquake. Scientists said tsunamis generated by volcanoes rather than earthquakes are relatively rare.

Rachel Afeaki-Taumoepeau, who chairs the New Zealand Tonga Business Council, said she hoped the relatively low level of the tsunami waves would have allowed most people to get to safety, although she worried about those living on islands closest to the volcano.

“We are praying that the damage is just to infrastructure and people were able to get to higher land,” she said.

The explosion of the Hunga Tonga Hunga Ha’apai volcano, about 64 kilometers (40 miles) north of Nuku’alofa, was the latest in a series of dramatic eruptions. In late 2014 and early 2015, eruptions created a small new island and disrupted international air travel to the Pacific archipelago for several days.

Earth imaging company Planet Labs PBC had watched the island in recent days after a new volcanic vent began erupting in late December. Satellite images showed how drastically the volcano had shaped the area, creating a growing island off Tonga.

___

Associated Press journalists Seth Borenstein in Kensington, Maryland, and Jill Lawless in London contributed to this report.

Wednesday, January 19, 2022

EXPLAINER: Why Tonga eruption was so big and what’s next

By NICK PERRY

FILE - This satellite image provided by Maxar Technologies shows an overview of Hunga Tonga Hunga Ha'apai volcano in Tonga on Jan. 6, 2022, before a huge undersea volcanic eruption. (Satellite image ©2022 Maxar Technologies via AP,

WELLINGTON, New Zealand (AP) — People around the world looked on in awe at the spectacular satellite images of an undersea volcano erupting in a giant mushroom cloud in the Pacific. Many wondered why the blast was so big, how the resulting tsunami traveled so far, and what will happen next. New Zealand scientists Shane Cronin, a volcanology professor at the University of Auckland, and Emily Lane, a tsunami expert at the National Institute of Water and Atmospheric Research, help explain.

EXPLOSIVE BUT BRIEF

The eruption on Saturday was incredibly explosive but also relatively brief. The plume rose into the air more than 30 kilometers (19 miles) but the eruption lasted only about 10 minutes, unlike some big eruptions that can continue for hours. Cronin said the power of the eruption of the Hunga Tonga Hunga Ha’apai volcano ranks among the world’s biggest over the past 30 years, and the height of the plume of ash, steam and gas was comparable with the huge 1991 eruption of Mount Pinatubo in the Philippines, which killed several hundred people

WHY SO BIG?

The magma inside the volcano was under enormous pressure and had gasses trapped within it. A fracture in the rock likely induced a sudden drop in pressure, allowing the gas to expand and blast the magma apart. Cronin said the crater was sitting about 200 meters (650 feet) below the sea surface, a kind of Goldilocks depth for a big explosion in which seawater pours into the volcano and turns instantly into steam, adding to the rapid expansion and energy of the explosion. Any deeper and the extra pressure of the water would have helped contain the eruption.

FARFLUNG TSUNAMI

Many scientists were surprised that a single eruption could produce a Pacific-wide tsunami of about 1 meter (3 feet) that smashed boats in New Zealand and caused an oil spill and two drownings in Peru. Lane said that oceanwide tsunamis are usually triggered by earthquakes that extend across huge areas rather than from a single volcano, essentially a tiny dot in the ocean. She said other factors may have been at play, such as an underwater flank of the volcano collapsing and displacing water. She said one interesting theory is that the shock wave, or sonic boom, from the volcano that traveled twice around the world may have pumped more power into the tsunami waves.

TONGA MAINLY SPARED

Another mystery is why the tsunami wasn’t bigger and more destructive in Tonga, which sits almost on top of the volcano.

“That’s the million dollar question,” Cronin said. “Looking at the images so far, the level of devastation is less than I was fearing.”

Authorities by Wednesday had confirmed three deaths in Tonga, with concerns remaining about people on some of the hard-hit smaller islands. Dozens of homes were destroyed.

Lane said that Tongans at least got some warning, both from the increased activity at the volcano the day before the eruption and from the incredibly loud bang when it erupted but before the tsunami hit, allowing many to scramble to higher ground. She said reefs, lagoons and other natural features may also have protected parts of Tonga, while amplifying the waves in certain areas.

FALLING ASH

The ash that has coated Tonga is acidic but not poisonous, Cronin said. Indeed, he has been advising Pacific responders that people may still be able to drink from their rainwater supplies even if some ash has fallen in, which will make the water more acidic and salty. He said it was a question of applying the taste test and if water became scarce, it would be better drinking ash-tainted water than stagnant water that might be contaminated with bacteria. New Zealand and other nations are trying to get water and other supplies to Tonga as quickly as possible. Cronin said all of Tonga’s soil comes from volcanic ash and the latest dump of ash would quickly wash into the ground and make the nation more fertile.

NO GLOBAL COOLING

Huge volcanic eruptions can sometimes cause temporary global cooling as sulfur dioxide is pumped into the stratosphere. But in the case of the Tonga eruption, initial satellite measurements indicated the amount of sulfur dioxide released would only have a tiny effect of perhaps 0.01 degree Celsius (0.02 Fahrenheit) global average cooling, said Alan Robock, a professor at Rutgers University.

WHAT’S NEXT

Cronin envisions two main scenarios for the volcano. The first is that it has exhausted itself for now and will go quiet for the next 10 to 20 years as magma slowly returns. A second scenario is that new magma rises up quickly to replace that which exploded, in which case there might be ongoing eruptions. But he believes the cracks and rifts caused by Saturday’s big explosion will allow more gas to escape, and subsequent eruptions won’t be as big, at least for now. Both Cronin and Lane agree there needs to be much better monitoring of the volcano — and others in Tonga — to help better predict future events.

___

Associated Press Science Writer Seth Borenstein in Kensington, Maryland, contributed to this report.

The science behind the Tonga volcanic eruption, tsunami

















Jan 18, 2022 6:20 PM EST
PBS NEWS HOUR
By —John Yang
By —Ali Rogin


The first satellite images of the Pacific nation of Tonga after Saturday's volcanic eruption emerged Tuesday. The photos show the islands coated in ash. Despite the violent explosion, the Tongan government has reported just three deaths. The status of two smaller islands in its chain is still unknown. John Yang takes a closer look at the science behind the volcano, its explosion and aftermath.

 Full Transcript

Judy Woodruff:

Today, the first satellite images emerged of the Pacific nation of Tonga following Saturday's volcanic eruption.

The photos show the islands coated in ash. Despite the violent explosion, the Tongan government has so far reported just three deaths. The status of two smaller islands in its chain is still unknown.

John Yang takes a closer look at the science behind the volcano, its explosion and aftermath.


John Yang:

Judy, scientists say the explosion revealed some of the mysteries of underwater volcanoes. It produced a tsunami that was felt on the coasts of Japan and the United States, 5,000 miles away, and triggered an oil spill in Peru. It set off a lightning storm that lasted seven hours and had 400,000 strikes. It was heard as far away as Alaska.

But for all the ways it made itself felt around the world, its damage was relatively confined. Tonga bore the brunt of the volcano's fury, blanketed with ash that is now contaminating its water supply.

Michael Poland is a research geophysicist with the U.S. Geological Survey's Cascades Volcano Observatory in Vancouver, Washington.

Mr. Poland, thanks so much for joining us. As we talk about, it was so dramatic, this event, that huge plume that was visible from space, the tsunami, the atmospheric shockwave which rippled around the globe, but you say that the data actually showed this was a relatively small eruption.

Explain that.


Michael Poland, U.S. Geological Survey:

Yes, it's a very confounding event, in that the amount of material that came out of the ground was not especially huge.

It was perhaps the kind of thing we might see every few years from a volcano somewhere on Earth. But it produced an outsized explosion, really a massive explosion. And that has to have something to do with the interaction with ocean water, and to produce that really massive tsunami.

So it's having really outsized impacts for the amount of material that came out of the ground.


John Yang:

And what was in that material? What did come out of the ground?


Michael Poland:

Well, there was a lot of ash that came out, of course, as with most volcanic eruptions, and SO2 gas, among other types of gas, water vapor, and so forth.

And that sulfur dioxide really allows us to pinpoint where the plume is and how big it is, because we know roughly the amount of sulfur gas that's dissolved in the magma. So it's a bit like opening a soda and having that carbon dioxide come out of the soda. When the gas comes out of the volcano, you get a lot of SO2 that comes out of that magma. That allows us to track the plume and know roughly how big an eruption is.


John Yang:

And you talk about the reaction with the ocean water. Does that also — or what's the explanation for it being heard so far away, heard as far away as Alaska?


Michael Poland:

Yes, that's really difficult to understand at this point.

It had to have something to do with that sort of interaction. Perhaps a large amount of gas-rich magma being suddenly exposed to cold ocean water generated just a really massive explosion, and it was heard obviously, very, very far away. That's something I think is going to be the subject of an awful lot of research in the days, years to come.


John Yang:

And the tsunami, I think a lot of people's familiarity with tsunamis really comes from the 2004 Banda Aceh tsunami, which was the result of an earthquake, of a seismic event.

Is this common, a tsunami also common with volcanic eruptions under underwater like this?


Michael Poland:

Volcanic eruptions that are right underwater or right near the water can generate tsunamis. It's not something we see a lot of. Certainly, we see the earthquake-induced tsunamis much more commonly.

There's a lot of study that went into earthquake-induced tsunami, especially after 2004. And we have come to understand those sorts of processes a lot better than we did before. But volcanic tsunamis being rare give us fewer opportunities to study them.

So we don't understand the volcanic tsunamis quite as well. So a bit like that airwave that traveled around the Earth, this tsunami is also going to be studied quite intently to understand more about what generated it. Was it some displacement of the seafloor? Was it perhaps the impact of an ash plume on the water?

There are many potential mechanisms for why the tsunami was so big. And understanding that is going to be key to being able to forecast these sorts of events in the future.


John Yang:

As I hear you talk, it sounds like there's a lot we don't understand about underwater volcanoes, and that this is suggesting ways or new research, as you say, to examine this one.

What sorts of things will you be looking at and your colleagues be looking at it in this event?


Michael Poland:

I think the key here is that magma-water interaction.

And so there's going to be all kinds of attention paid to how magma and water interact. What happens when you put these two different materials in contact with another really in a dynamic way. So we're going to be looking at modeling studies of those sorts of interactions, studying the ash particles to see whether that can provide some clues as to how the interaction took place, and then modeling this explosion, modeling the tsunami, to try to understand more about the nature of this interaction, because, obviously, there are submarine volcanoes in other places.

And they're tremendously hard to study, because they are obscured. It's relatively easy to study volcanoes on land compared to these underwater volcanoes. But, clearly, they present a hazard. So we need to understand more about that hazard.

This event, as tragic as it is for Tonga, might help us understand these kinds of interactions in more detail. And that will help us in the future.


John Yang:

It's fascinating stuff.

Research geophysicist Michael Poland, thank you very much.


Michael Poland:

My pleasure.

Tuesday, January 18, 2022

Despite huge volcano blast, Tonga avoids widespread disaster
By NICK PERRY

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In this photo provided by the New Zealand Defense Force, volcanic ash covers roof tops and vegetation in an area of Tonga, Monday, Jan. 17, 2022. Thick ash on an airport runway was delaying aid deliveries to the Pacific island nation of Tonga, where significant damage was being reported days after a huge undersea volcanic eruption and tsunami. (CPL Vanessa Parker/NZDF via AP)


WELLINGTON, New Zealand (AP) — The blast from the volcano could be heard in Alaska, and the waves crossed the ocean to cause an oil spill and two drownings in Peru. The startling satellite images resembled a massive nuclear explosion.

And yet, despite sitting almost on top of the volcano that erupted so violently on Saturday, the Pacific nation of Tonga appears to have avoided the widespread disaster that many initially feared.

Perhaps the biggest problem is the ash that has coated the main island and transformed it into a gray moonscape, contaminating the rainwater that people rely on to drink. New Zealand’s military is sending fresh water and other much-needed supplies, but said Tuesday the ash covering Tonga’s main runway will delay the flight at least another day.

Tonga has so far reported two deaths, and concerns remain over the fate of people on two smaller islands that were hard hit. Communications have been down everywhere, making assessments more difficult.

But on the main island of Tongatapu, at least, life is slowly returning to normal. The tsunami that swept over coastal areas after the eruption was frightening for many but rose only about 80 centimeters (2.7 feet), allowing most to escape.

“We did hold grave fears, given the magnitude of what we saw in that unprecedented blast,” said Katie Greenwood, the head of delegation in the Pacific for the International Federation of Red Cross and Red Crescent Societies. “Fortunately, in those major population centers we are not seeing the catastrophic effect we thought might happen, and that’s very good news.”



Greenwood, who is based in Fiji and has been talking with people in Tonga by satellite phone, said an estimated 50 homes were destroyed on Tongatapu but that nobody needed to use emergency shelters. She said about 90 people on the nearby island of ’Eua were using shelters.

U.N. humanitarian officials and Tonga’s government has reported “significant infrastructural damage” around Tongatapu.

“There has been no contact from the Ha’apai Group of islands, and we are particularly concerned about two small low-lying islands — Mango and Fonoi — following surveillance flights confirming substantial property damage,” U.N. spokesman Stephane Dujarric said.

New Zealand’s High Commission in Tonga also reported significant damage along the western coast of Tongatapu, including to resorts and the waterfront area.

Like other island nations in the Pacific, Tonga is regularly exposed to the extremes of nature, whether it be cyclones or earthquakes, making people more resilient to the challenges they bring.

Indeed, Greenwood said Tonga does not want an influx of aid workers following the eruption. Tonga is one of the few remaining places in the world that has managed to avoid any outbreaks of the coronavirus, and officials fear that if outsiders bring in the virus it could create a much bigger disaster than the one they’re already facing.

Another worry, said Greenwood, is that the volcano could erupt again. She said there is currently no working equipment around it which could help predict such an event.

Satellite images captured the spectacular eruption of the Hunga Tonga Hunga Ha’apai volcano on Saturday, with a plume of ash, steam and gas rising like a giant mushroom above the South Pacific. The volcano is located about 64 kilometers (40 miles) north of Tonga’s capital, Nuku’alofa.

Two people drowned in Peru, which also reported the oil spill after waves moved a ship that was transferring oil at a refinery.

In Tonga, British woman Angela Glover, 50, was one of those who died after being swept away by a wave, her family said.

Nick Eleini said his sister’s body had been found and that her husband survived. “I understand that this terrible accident came about as they tried to rescue their dogs,” Eleini told Sky News. He said it had been his sister’s life dream to live in the South Pacific and “she loved her life there.”

New Zealand’s military said it hoped the airfield in Tonga would be opened either Wednesday or Thursday. The military said it had considered an airdrop but that was “not the preference of the Tongan authorities.”

New Zealand also sent a navy ship to Tonga on Tuesday, with another planned to leave later in the day, and pledged an initial 1 million New Zealand dollars ($680,000) toward recovery efforts.

Australia sent a navy ship from Sydney to Brisbane to prepare for a support mission if needed.

Chinese Foreign Ministry spokesperson Zhao Lijian on Tuesday said China is preparing to send drinking water, food, personal protective equipment and other supplies to Tonga as soon as flights resume.

The U.N. World Food Program is exploring how to bring in relief supplies and more staff and has received a request to restore communication lines in Tonga, which is home to about 105,000 people, Dujarric said.

Communications with the island nation are limited because the single underwater fiber-optic cable that connects Tonga to the rest of the world was likely severed in the eruption. The company that owns the cable said the repairs could take weeks.

Samiuela Fonua, who chairs the board at Tonga Cable Ltd., said the cable appeared to have been severed soon after the eruption. He said the cable lies atop and within coral reef, which can be sharp.

Fonua said a ship would need to pull up the cable to assess the damage and then crews would need to fix it. A single break might take a week to repair, he said, while multiple breaks could take up to three weeks. He added that it was unclear when it would be safe for a ship to venture near the undersea volcano to undertake the work.

A second undersea cable that connects the islands within Tonga also appeared to have been severed, Fonua said. However, a local phone network was working, allowing Tongans to call each other. But he said the lingering ash cloud was continuing to make even satellite phone calls abroad difficult.

___

Associated Press journalist Jill Lawless in London contributed to this report.

Friday, January 21, 2022

Fisherman recalls racing tsunami, raining rocks after Tongan volcano erupted

Smoke and ash billowing from the eruption of the Hunga Tonga-Hunga Ha'apai volcano on Jan 14, 2022. PHOTO: REUTERS/TONGA GEOLOGICAL SERVICES

SYDNEY (REUTERS) - Mr Branko Sugar and his son were spearfishing on an outer reef in Tonga last Saturday (Jan 15).

The air smelt of sulphur, as it had done for weeks, from the nearby active volcano, but he noticed the ash cloud from the crater was much higher.

As the 61-year-old stowed away his spearfishing gear, the first of four loud volcanic explosions rocked the tranquil South Pacific, sending a giant wave towards his boat.


"We stopped the boat and just looked. Then we saw the wave coming towards us. The biggest wave I've ever seen," Mr Sugar told Reuters via telephone from Tonga on Friday where communications are still only being restored.

Mr Sugar turned his boat, a 400-horsepower 27-foot (8m) World Cat catamaran, and accelerated towards deep water near Eueiki Island.

"That's what saved us, the power of the boat," he said. "I shouldn't be alive."

As he raced for safety, Mr Sugar telephoned his home on Tonga's main island Tongatapu to warn of the approaching tsunami, but nobody answered.

"The wave came past us and hit the main island, and then we knew we'd managed to get away. But then the rocks started raining. It was raining stones," he recalled.

In minutes, the Pacific blue sky turned to total darkness, ash enveloped everything and a storm seemed to whip up, lashing the boat with wind and waves.

A 12-mile (19km) trip home took three hours in the darkness before they reached the harbour.

"There were wrecked boats everywhere. Upside-down boats, sunken boats. We didn't know where to go," Mr Sugar said.

"And when we finally stopped, then we couldn't find our cars - they'd all been swept away. It was one thing after another. When we finally found them, I couldn't drive, I was blind from rocks pounding my eyes for hours driving the boat."

The Hunga Tonga-Hunga Ha'apai volcano eruption triggered tsunami that destroyed villages, resorts and many buildings and knocked out communications for the nation of about 105,000 people. It also sent shockwaves and tsunami across the Pacific.

Three people have been reported killed, say Tongan authorities.

Nasa's Goddard Space Flight Centre has said the force of the eruption was estimated to be the equivalent of five to 10 megatons of TNT, or more than 500 times that of the nuclear bomb the United States dropped on the Japanese city of Hiroshima at the end of World War II.

The volcanic explosion in Tonga destroyed an island—and created many mysteries

Maya Wei-Haas

For many years, the Hunga Tonga-Hunga Ha'apai volcano poked above the waves as a pair of narrow rocky isles, one named Hunga Tong and the other Hunga Ha'apai. An eruption in 2014 built up a third island that later connected the trio into one landmass. And when the volcano awoke in December, the uninhabited island at the peak's tip slowly grew as bits of volcanic rock and ash built up new land.

 
© Provided by National Geographic

Then came the catastrophic eruption on January 15. As seen in satellite images, only two tiny outcrops of rock now betray the beast lurking beneath the waves. But whether it happens in weeks or years, the volcano will rise again.

This cycle of destruction and rebirth is the lifeblood of volcanoes like Hunga Tonga-Hunga Ha'apai, which is just one of many that dot the Kingdom of Tonga. Still, the tremendous energy of this latest explosion, which NASA estimated to be equivalent to five to six million tons of TNT, is unlike any seen in recent decades. The eruption sent a tsunami racing across the Pacific Ocean. It unleashed a sonic boom that zipped around the world twice. It sent a plume of ash and gas shooting into the stratosphere some 19 miles high, with some parts reaching as far as 34 miles up. And perhaps most remarkable, all these effects came from only an hour or so of volcanic fury.
© Provided by National Geographic

"Everything so far about this eruption is off-the-scale weird," says Janine Krippner, a volcanologist with Smithsonian's Global Volcanism Program.

© Photograph by New Zealand Defense Force via Getty Images A blanket of ash has dulled the usually vibrant plantlife across the string of tropical islands, as shown in this January 17 image of Nomuka, where the tsunami caused extensive damage.

Scientists are now racing to work out the cause behind this week’s intense outburst and the surprisingly widespread tsunamis that followed. Some clues to what set the stage for such a powerful explosion may come from the chemistry of rocks that cooled from lava in past eruptions. In a new study published in the journal Lithos, scientists found key differences between the erupted material of small and large blasts—and now they are curious what the chemistry of this latest event might reveal.

Understanding the spark that ignited Hunga Tonga-Hunga Ha'apai’s recent explosive event could help reduce future risks. For now, however, the biggest concern is for the people of Tonga, and whether there could be more volcanic outbursts on the horizon. Almost all of the volcano is now beneath the ocean surface, hidden from satellite view, and there's no equipment on the ground to help track subterranean shifts of molten rock

.
© Photograph by Japan Meteorology Agency via AP Multiple satellites captured the volcano’s tremendous blast as a billowing plume of ash and gas shot into the stratosphere. The eruption is shown here in an image taken by Himawari-8, a Japanese weather satellite.

"If we can't detect what is happening in the magma system, we have no idea what might happen next," Krippner says.

An underwater giant


While Hunga Tonga-Hunga Ha'apai has erupted many times in the past, scientists only recently realized how large these eruptions could be. Mostly submerged underwater, the volcano is not easy to study.

"No one had actually done any work on the rocks," says Simon Barker, a volcanologist at Victoria University of Wellington in New Zealand and an author of the new Lithos study documenting the volcano's history.

Barker and his colleagues chartered a boat in 2015 to camp for several nights on the volcanic island’s rubbly landscape. As they surveyed the region and collected samples of rock, the team spotted small cones from recent eruptions dotting the seafloor around the primary peak. They also discovered thick layers of fragmented lava rocks and ash, known as pyroclastic flows, from two monstrous eruptions that they later dated to around 900 and 1,800 years old.

"We saw there was a lot more complexity to the history of the volcano," Barker says.

The chemistry of erupted material might help untangle what made this eruption so powerful, explains Marco Brenna, a volcanologist at the University of Otago in New Zealand and an author of the new Lithos study.

As a magma system cools, crystals of different minerals form at different times, which changes the chemistry of the dwindling molten rock. The crystals preserve these changes as they grow, a little like tree rings.

Brenna and his colleagues analyzed the rings of crystals in the rocks that erupted during the two large blasts 900 and 1,800 years ago. Their work suggests that before the volcano unleashed these eruptions, fresh magma was rapidly injected into the chamber—a commonly proposed trigger for many volcanic eruptions. But the rocks from more moderate explosions in 2008 and 2015 lacked these rings, pointing to a constant but slow influx of magma, Brenna says.

Scientists are now hoping to study the chemistry of the freshly erupted rock to see what it can tell us about this latest event. "It'll be interesting to see what the crystals are recording," Brenna says.

While these subterranean processes may be driving part of the explosivity, water also likely had a hand in this weekend's blasts, says Geoff Kilgour, a volcanologist with New Zealand's GNS Science who was not part of the study team. Water can supercharge the power of a volcanic explosion, but it remains unclear exactly how it would have sparked the astounding boom from Hunga Tonga-Hunga Ha'apai.

Perhaps, Kilgour suggests, the recent explosion had just the right mix of magma and water; an excess of either one would have generated a more moderate blast. "It may be that we've gotten to this Goldilocks zone," he says.
Airblast tsunami?

This latest eruption is layering on even more intrigue because its mighty boom, while energetic, ejected surprisingly little material. Ash from the volcano's past large eruptions can be found on the nearby island of Tongatapu, and that layer is 10 times thicker than the new layer deposited there by the recent event, Barker says.

Some scientists now speculate that the enormous, short-lived burst of energy may have helped stir up the unusually large tsunami waves that followed the eruption.

Tsunamis usually radiate from a sudden underwater shift, like a submarine landslide down a volcano's flanks or rapid movement of the land in an earthquake. Yet after Hunga Tonga-Hunga Ha'apai erupted, waves appeared in some places, such as the Caribbean, far earlier than would be expected of a classic tsunami.

The later tsunami waves that crashed on distant shores were also strange. The farther from the trigger a tsunami travels, the more its waves should diminish. While the waves that hit the islands in the Kingdom of Tonga were damaging, they weren't high enough to account for the surprisingly large waves across the ocean.

"It basically had a very low decay of tsunami size all around the Pacific, which is really, really unusual," Kilgour says. The shockwave that traveled through the air could have coupled with the sea surface, driving the expansive tsunamis. Just such a process was proposed for the 1883 explosion of Krakatoa, one of the most powerful and deadly volcanic eruptions in recorded history.

Modeling the spread and timing of the waves along with mapping changes to the volcano could help explain what drove the large tsunami. Still, Krippner says, the confusing mix of events "is going to change the way we look at this style of eruption—and that doesn't happen that often."
Trying to monitor a hidden giant

The recent event and all its oddities highlight how little is known about submarine volcanoes, says Jackie Caplan-Auerbach, a seismologist with Western Washington University. Many of these submerged giants linger in the deep ocean, and their blasts usually aren't deadly. Yet this weekend's explosion is a stark reminder of the risks of volcanoes lingering just beneath the waves.

For now, Hunga Tonga-Hunga Ha'apai seems to have fallen silent. The locals are helping each other pick through the damage and clean up the streets. While communications remain largely severed, information about the current situation is finally starting to trickle out. Three deaths have been confirmed among Tonga's residents, with two additional deaths in Peru from the tsunami.

Damage on some of the islands is severe. The homes of all 36 residents of Mango Island have been destroyed. Just two houses still stand on Fonoifua Island, and extensive damage stretches across Nomuka Island, which has a population of 239. Damage to the largest and most populous island, Tongatapu, where about 75,000 people live, was mostly focused on the western side. The Tonga Red Cross estimates a total of 1,200 "affected households."

Ash has contaminated the islands' stores of drinking water and delayed planes from landing with additional supplies. The New Zealand navy has deployed two supply ships that are scheduled to arrive on January 21.

And there's still a risk that the volcano could have more explosive blasts in store. The Tonga Geological Services relies on visual and satellite observations to track the activity of the many volcanoes across the region. But with Hunga Tonga-Hunga Ha'apai’s volcanic tip now beneath the surface, scientists have lost sight of any signs that might help understand the volcano's activity. The potential for additional activity also prevents scientists from flying nearby for a closer look.

Even when the volcano isn't actively erupting, monitoring largely submarine volcanoes is a complex task. GPS—which is frequently used to track shifts in the surface as magma moves underground—doesn't work on the seafloor. And obtaining real-time data from seismometers on the ocean floor is technologically difficult and expensive. Caplan-Auerbach says she often likens working in the oceans to doing seismology on another planet.

Instruments known as hydrophones can listen to the grumbles of submarine volcanoes as the sound travels across vast tracts of the ocean. But these are not easy to deploy in emergency situations and require connection to underwater cables for real-time data.

The situation in Tonga highlights the need for better international efforts to fund volcano monitoring around the world, Krippner says. She and other volcanologists have all stressed how well the Tonga Geological Services is handling a near-impossible task. "They don't have a huge amount of money. They don't have a huge amount of staff," Kilgour says. "But they're asked to do a huge amount."

In the days leading up to the January 15 blast, based on visual and satellite information alone, the agency persistently warned of future eruptions and a potential tsunami, instructing locals to stay away from the beaches. "Because of that, I think they saved probably thousands of lives," Barker says.

"We often learn from these really dreadful times," Caplan-Aurbach adds. Perhaps by closely studying the aftermath of this volcanic explosion, "we'll have a better sense for what's coming."


Sunday, June 25, 2023

ICYMI
'Nothing comparable': Volcanic eruption caused the most intense lightning storm on record


Doyle Rice, USA TODAY
Fri, June 23, 2023 

Wow.

Last year's colossal eruption of the Hunga undersea volcano near Tonga produced the most intense lightning storm ever recorded on Earth, scientists announced in a new study published this week.

In fact, at one point during the 11-hour lightning storm, an incredible 2,600 flashes per minute were recorded.

“This eruption triggered a supercharged thunderstorm, the likes of which we’ve never seen,” said Alexa Van Eaton, a volcanologist at the United States Geological Survey, who led the study.

The study was published in Geophysical Research Letters, a publication of the American Geophysical Union. Previously, the annual lightning report from Vaisala estimated The Hunga Tonga volcano explosion generated hundreds of thousands of lightning events in just six hours, the most extreme concentration of lightning ever detected.

Amazing facts about the eruption and lightning storm

The eruption lasted at least 11 hours, several hours longer than previously known

There were a total of 200,000 lightning flashes during the storm

The volcanic plume produced the highest-altitude lightning flashes ever measured, at some 12 to 19 miles above sea level

Lightning “surfed” giant waves that rippled through the volcanic plume


An image from footage by Japan's Himawari-8 satellite and released by the National Institute of Information and Communications (Japan) on Jan. 15, 2022 shows the volcanic eruption that provoked a tsunami in Tonga. The eruption was so intense it was heard as "loud thunder sounds" in Fiji more than 500 miles) away.

'We’ve never seen anything like that before'

High-resolution lightning data from four separate sources – never previously used all together – have now let scientists peer into the volcanic plume from the event, teasing out new phases of the eruption’s life cycle and gaining insights into the weird weather it created, the study said.

“With this eruption, we discovered that volcanic plumes can create the conditions for lightning far beyond the realm of meteorological thunderstorms we’ve previously observed,” Van Eaton said. “It turns out, volcanic eruptions can create more extreme lightning than any other kind of storm on Earth.”

According to the study, that also includes lightning that comes from supercell thunderstorms and from hurricanes.

“It wasn’t just the lightning intensity that drew us in,” Van Eaton added. She and her colleagues were also puzzled by the concentric rings of lightning, centered on the volcano, that expanded and contracted over time.

“The scale of these lightning rings blew our minds. We’ve never seen anything like that before, there’s nothing comparable in meteorological storms. Single lightning rings have been observed, but not multiples, and they’re tiny by comparison.”

More lightning info: Video shows fiery lightning strike at North Carolina motorsports company


The January 15, 2022, eruption of Tonga’s Hunga volcano produced a “supercharged” storm in the volcanic plume that had the most intense lightning ever recorded in a storm, according to a new study.
An 'explosive event'

The volcano, which is located in the southern Pacific Ocean, began erupting in December 2021, but its most explosive event did not occur until Jan. 15, 2022, Space.com said.

During the Jan. 15 eruption, it generated atmospheric shock waves, sonic booms and tsunami waves that traveled the world, according to NASA. It was the most powerful atmospheric explosion ever recorded on the planet.

At least six people died as a result of the eruption worldwide.

Contributing: Dinah Voyles Pulver

Violent Volcano Eruption Triggers an Ungodly Number of Lightning Flashes



Frank Landymore
FUTURISM
Sat, June 24, 2023

Zeus's Playground


The eruption of the underwater Hunga volcano in the southern Pacific Ocean produced the most intense lightning storm ever recorded.

According to a new study published in the journal Geophysical Research Letters, the resulting "supercharged" thunderstorm crackled with an unholy 2,600 flashes every minute at its peak, totaling nearly 200,000 flashes overall.

"This eruption triggered a supercharged thunderstorm, the likes of which we've never seen," said lead author Alexa Van Eaton, a volcanologist at the US Geographical Survey, in a statement.

If that isn't already insane enough, Van Eaton says the team observed massive lightning rings centered above the volcano, which continuously expanded and contracted.

"The scale of these lightning rings blew our minds," Van Eaton said. "We've never seen anything like that before, there's nothing comparable in meteorological storms."

Perfect Storm


Van Eaton explains that Hunga's eruption — which itself is one of the most powerful in history — blasted molten rock and volcanic ash through the ocean, sending a towering plume over 36 miles into the air. This form of eruption is called "phreatoplinian," and nothing of its kind has ever been observed with modern instruments.

On the way up, the molten material vaporized the seawater, which rose into the air and mingled with the ashy plume that continued to expand laterally after hitting its maximum height.

Now, all mixed together in a hellish brew, the collisions between the ash and the water generated incredible amounts of electricity — the ideal environment for lightning.

"With this eruption, we discovered that volcanic plumes can create the conditions for lightning far beyond the realm of meteorological thunderstorms we've previously observed," Van Eaton said. "It turns out, volcanic eruptions can create more extreme lightning than any other kind of storm on Earth."
Hell On Earth

This almighty display of power was only recorded thanks to a novel technique that combined lightning data from four different sources, using a mixture of light and radio wave sensors. Otherwise, the plume would have been too thick to penetrate.

From carefully combining the data, Van Eaton and her team observed the astonishing 192,000 lightning strikes, some originating from an "unprecedented" altitude of 19 miles.

This technique for observing the lightning strikes also proved invaluable in measuring the eruption's duration. Because the plume obstructed the volcanic vent, the researchers had to rely on lightning data to understand how long the eruptions persisted.

"The January 15 activity created volcanic plumes for at least 11 hours," Van Eaton said. "It was really only from looking at the lightning data that we were able to pull that out."

Wednesday, November 15, 2023

VULCANOLOGY
'Time's finally up': Impending Iceland eruption is part of centuries-long volcanic pulse

Hannah Osborne
Tue, November 14, 2023 

Fagradalsfjall volcano in Iceland erupting at dusk


Iceland's potentially imminent eruption in the Reykjanes Peninsula is part of a 1,000-year cycle of volcanic activity that will likely cause eruptions for centuries, scientists say.

"Time's finally up," Edward W. Marshall, a researcher at the University of Iceland's Nordic Volcanological Center, told Live Science in an email. "We can get ready for another few hundred years of eruptions on the Reykjanes."

Seismic activity began increasing in the south of the peninsula in October, with hundreds of earthquakes recorded there each day. On Nov. 10, authorities evacuated the town of Grindavík, with experts warning an volcanic eruption could take place in just days.


Infographic showing the seismic activity that has hit Iceland in recent weeks

According to the Icelandic Met Office (IMO), a magma tunnel stretching 9.3 miles (15 kilometers) formed beneath the ground between Sundhnúkur in the north and Grindavík. The area affected also encompasses the Blue Lagoon geothermal spa — a tourist hotspot that attracts hundreds of thousands of visitors annually.

Magma in the tunnel — also known as a dike — appears to be rising to the surface, and there is a high risk of it breaking through. The greatest area of magma upwelling is currently close to Sundhnúkur, about 2 miles (3.5 km) northeast of Grindavík, according to the IMO. Researchers believe the amount of magma in the tunnel is "significantly more" than what was present during the eruptions at Fagradalsfjall, which sparked back to life in 2021 after more than 800 years of inactivity.

That 2021 eruption marked the start of a new cycle of volcanic activity on the Reykjanes Peninsula. Geological records show periods of inactivity last between 600 and 1,200 years, which is then followed by pulses of eruptions lasting between 200 and 500 years, Clive Oppenheimer, a professor of volcanology at the University of Cambridge in the U.K., told Live Science in an email.

"It looks like 2021 kicked off a new eruptive phase which might see the several fault zones crossing the [Reykjanes Peninsula] firing on and off for centuries," he said.

vehicles leaving the town of Grindavik, southwestern Iceland, during evacuation following earthquakes., with the sea in the background

The Reykjanes Peninsula sits above two tectonic plates that are being pulled apart. The strain that builds up is released in bursts as part of the cycle. "We are now in one of these pulses," David Pyle, a volcanologist and professor of Earth sciences at the University of Oxford, U.K, told Live Science in an email. "Each eruption releases just a bit more of the stored-up strain, and eventually, when all of that strain has been released, then the eruptions will stop."

It is currently unclear if an eruption will take place as a result of the magma tunnel. "These sorts of dikes are actually a tectonic, not a magmatic feature. In other words, the lava is filling a fracture, not forcing its way into the rock," Marshall said.

Should a fissure emerge, an eruption could last for several weeks. The large amount of magma involved compared with previous eruptions in the region could result in more lava flow at the surface, Oppenheimer said.

What happens next is a waiting game, Marshall said. "I predict — if an eruption occurs — that it will occur between a few days to threeish weeks. If it hasn't erupted in three weeks, I don't think it will happen. Cooling will begin to close the fractures."

Related:
Where is the largest active volcano in the world?

Emilee Speck
Tue, November 14, 2023 


Hawaii's Mauna Loa is the largest active volcano on Earth, with the summit more than 10 miles above its base, according to the U.S. Geological Survey.

Located inside Hawai'i Volcanoes National Park, Mauna Loa makes up more than half of the Big Island, standing at 13,681 feet above sea level, according to the National Park.

About 30,000 feet of Mauna Loa starts from the bottom of the sea, about 1,000 feet taller than Mount Everest, the planet's highest mountain above sea level.

WHAT ARE THE 4 CLASSIC TYPES OF VOLCANOES?

Hawaii's Mauna Kea volcano is taller at 33,500 feet. However, Mauna Loa is much larger by volume, according to the USGS.

Map notes the locations of Mauna Loa, along with nearby sister volcano Kilauea.

Mauna Loa is so massive that the sea floor caves in another 5 miles from the weight of the volcano.

Including the most recent eruption in November 2022, Mauna Loa has erupted 34 times since its first well-documented eruption in 1843, according to the USGS Hawaiian Volcano Observatory.

The 12-day eruption in 2022 marked the first since 1984.

About two months before its last eruption, Mauna Loa began displaying increased seismic activity, one of the signs geologists look for when an eruption is imminent.

WHAT HAPPENS BEFORE A VOLCANO ERUPTS?

Since its 2022 eruption, Mauna Loa has been mostly quiet, according to the Hawaii Volcano Observatory, but remains active with increasing seismic activity as recently as October.

Only about 20 miles from Mauna Loa, KÄ«lauea is Hawaii's second-largest active volcano and most recently erupted in September.

Mauna Loa and KÄ«lauea are classic examples of shield volcanoes and are among the most active in the world.

This type of volcano is typically the largest on Earth and covers a broad swath of terrain.

Volcanologists say the great width of these volcanoes is a result of thin lava flows. Eruptions are not considered to be eruptive and usually rank low on the VEI. Threats from landslides and volcanic smog are usually significant for these types of volcanoes.

Original article source: Where is the largest active volcano in the world?

Can one volcano's eruption trigger an eruption at another volcano?

Emilee Speck
Mon, November 13, 2023 


When there is one volcano in a region, there can be several or many others nearby, but if one volcano erupts, can that trigger an eruption at a nearby volcano or hundreds of miles away?

According to the U.S. Geological Survey, it is difficult to determine if one eruption caused another.

Active volcanic regions, such as the Rabaul Caldera in Papua New Guinea and Iceland's Reykjanes volcanic region, sometimes have common magma reservoirs that can trigger unrest.

WHAT HAPPENS BEFORE A VOLCANO ERUPTS?

According to the USGS, the largest volcano eruption in the 20th century happened in 1912 when Alaska’s Novarupta volcano began spewing magma that came from a reservoir 6 miles away beneath Mount Katmai. Even though it was the source of the magma, Mount Katmai did not erupt.

There are also volcanoes near one another that do not share this magma system, like Hawaii's Kilauea volcano, only 20 miles from Mauna Loa, but the two have individual magma reservoirs, according to the USGS.

There are multiple ongoing active eruptions worldwide at one time, and between 60 and 70 eruptions a year.

Most recently, officials warned of an impending volcanic eruption in Grindavík, Iceland, where the town has been evacuated following thousands of earthquakes. At the same time, Italy's Mount Etna began spewing lava fountains in the sky in November, just months after its August eruption.

However, according to the USGS, no definitive evidence exists that one eruption can trigger another eruption from a different volcano system that is hundreds of miles away or even on a different continent.

WHAT ARE THE 4 CLASSIC TYPES OF VOLCANOES?

There are signs of an impending eruption, including earthquakes, ground deformation and changes in gas emissions. Still, geology experts say predicting an eruption is not an exact science.

There are some historical examples of simultaneous eruptions within about 6 miles, but the USGS said it's unclear if one eruption caused the other.

Russia's tallest volcano spews out 1,000-mile-long river of smoke after giant eruption, satellite images reveal

Harry Baker
Tue, November 14, 2023 

A dark cloud of smoke flows from a lava flow on a volcano

Eurasia's tallest volcano has violently erupted, throwing a 1,000-mile-long (1,600 kilometers) cloud of dust and ash into the air, new NASA satellite images show.

Klyuchevskoy, sometimes referred to as Klyuchevskaya Sopka, is an active stratovolcano in Russia's Kamchatka Peninsula, which is home to more than 300 other volcanos. Klyuchevskoy's peak stands at 15,584 feet (4,750 meters) above sea level, making it taller than any other volcano in Asia or Europe, according to the Kamchatka Volcanic Eruption Response Team (KVERT).

Klyuchevskoy has been continually erupting since mid-June. But on Nov. 1, a massive volcanic explosion released a torrent of smoke and ash, which reached a maximum height of 7.5 miles (12 km) above Earth's surface, according to NASA's Earth Observatory.

The smoke and ash plume prompted KVERT to temporarily raise the aviation alert level to red (the highest possible level), which grounded planes in the area. Several schools were also evacuated due to the increase in air pollution.

The Landsat 8 satellite, which is co-run by NASA and the U.S. Geological Survey, captured a striking false-color image of the eruption plume (shown above), in which the red lava plume and grey smoke stand out against the surrounding blue-colored clouds.

NASA's Aqua satellite also captured a wider true-color image of the plume (shown below), which shows that the river of smoke was around 1,000 miles long at the time. But the plume may have eventually stretched up to 1,400 miles (2,255 km) long, according to the Smithsonian Institution's Global Volcanism Program.

Related: The 12 biggest volcanic eruptions in recorded history

The outburst only lasted for a few days, and it now appears that Klyuchevskoy may have stopped erupting altogether, according to KVERT.

The Kamchatka Peninsula is part of the Pacific Ring of Fire — a 25,000-mile-long (40,200 km) tectonic belt that circumscribes the Pacific Ocean and contains around three-quarters of the world's active volcanos.

The Ring of Fire has also recently been active in other areas: On Oct. 30, an underwater volcanic eruption off the coast of the Japanese island Iwo Jima birthed a brand new tiny island of hardened magma, which can also be seen from space.






A satellite image of a large eruption plume stretching across Russia and the Pacific Ocean

While the trail of smoke and ash given off by Klyuchevskoy was enormous, it is still quite a way off some of the largest eruption plumes ever seen.

The tallest eruption plume in recorded history was the towering pillar of smoke, ash and water vapor from the eruption of Tonga's underwater volcano in January 2022, which rose to 35.4 miles (57 km) above sea level.

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Following the Tonga eruption, scientists warned that the record amount of water vapor it released into the stratosphere could weaken the ozone layer. And in September this year, scientists partially attributed the eruption as the cause of an unusually large ozone hole above Antarctica.

However, Klyuchevskoy's latest eruption plume will likely have no real impact on the ozone layer because it contained much less water vapor and did not reach as high up in the atmosphere.