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2022 Hunga Tonga–Hunga Haʻapai eruption and tsunami. In December 2021, an eruption began on Hunga Tonga–Hunga Haʻapai, a submarine volcano in the Tongan archipelago in the southern Pacific Ocean. [6] . The eruption reached a very large and powerful climax nearly four weeks later, on 15 January 2022. [7] .
2022年8月2日 · When the Hunga Tonga-Hunga Ha’apai volcano erupted on Jan. 15, it sent a tsunami racing around the world and set off a sonic boom that circled the globe twice. The underwater eruption in the South Pacific Ocean also blasted an enormous plume of water vapor into Earth’s stratosphere – enough to fill more than 58,000 Olympic-size swimming pools.
2022年1月18日 · BBC News. A massive volcanic eruption in Tonga, on Saturday, triggered a tsunami that spread across the Pacific in a matter of hours. Waves hit Australia, New Zealand and Japan as well as the...
- Overview
- A volcanic powerhouse in the Pacific
- The volcano’s menacing maelstrom
- The Hephaestion hammer falls
- A foggy future in Tonga
The volcanic plume generated record amounts of lightning before producing a blast heard thousands of miles away. Here’s what geologists say drove the event—and what may happen next.
Just a few weeks ago, a submarine volcano identifiable by two small uninhabitable islands in the Kingdom of Tonga began to erupt. Its outburst initially seemed innocuous, with ashen plumes and moderate explosions that few people living outside the archipelago noticed.
But in the past 24 hours, that volcano, named Hunga Tonga-Hunga Ha'apai, forced the world to sit up and pay attention.
After a moment of calm earlier this month, its eruptive activity turned increasingly violent. The middle section of the island vanished on satellite imagery. Towering columns of ash began to produce record-breaking amounts of lightning.
“The thing just went gangbusters,” says Chris Vagasky, meteorologist and lightning applications manager at the Finland-based weather measurements company Vaisala. “We were starting to get 5,000 or 6,000 events per minute. That’s a hundred events per second. It’s unbelievable.”
Then, early in the morning on January 15, the volcano produced a colossal explosion. The atmosphere was blasted out of the way as a shockwave emanated from the island, radiating outward at close to the speed of sound. The sonic boom was heard in parts of New Zealand more than 1,300 miles away, with the shockwave eventually traveling halfway around the world—as far as the United Kingdom, which is located a staggering 10,000 miles distant.
Hunga Tonga-Hunga Ha'apai is located in region of the South Pacific that’s jam-packed with volcanoes—some above the waves, some far below—that have a penchant for violent eruptions. Past events have unleashed city-size rafts of pumice or seen volcanoes blowing themselves apart only to build new islands immediately afterward.
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This profusion of volcanoes exists because of the Pacific plate’s continuous dive beneath the Australian tectonic plate. As the slab descends into the superhot rocks of the mantle, the water inside gets baked out and rises into the mantle above. Adding water to these rocks causes them to more readily melt. This creates a lot of magma that tends to be sticky and filled with gas—a potent recipe for explosive eruptions.
Hunga Tonga-Hunga Ha'apai is no exception to this rule. The bits of land sit above a volcano more than 12 miles wide featuring a cauldron-like pit about three miles across, hidden from view by the sea. It’s been seen erupting with vim and vigor as far back as 1912, sometimes popping above the waves before being eroded away. The eruption of 2014-15 created a stable island that was soon home to colorful plants and barn owls.
As the volcano’s explosivity began to intensify, the amount of lightning emerging from its ashy plume began to eclipse not only that seen during this eruption, but during any eruption ever recorded.
Volcanoes can produce lightning because ash particles in their plumes bump into each other or into bits of ice in the atmosphere, which generates an electrical charge. Positive charges get segregated from negative ones, sparking a flash of lightning. (Learn more about how volcanoes can trigger lightning.)
From the outset, the Tonga eruption’s lightning was detected by Vaisala’s GLD360 network, which uses a global distribution of radio receivers that can “hear” the lightning as intense bursts of radio waves. During the first two weeks, the system recorded sometimes a few hundred or a few thousand flashes per day—nothing unusual. “It was clearing its throat, I guess,” says Vagasky.
There was nowhere else that was that electric on the planet last night.
ByChris VagaskyVaisala meteorologist
But by late Friday into early Saturday, the volcano was producing tens of thousands of discharges. At one point, this Tongan volcano managed 200,000 discharges in a single hour. By comparison, the 2018 eruption of Indonesia’s Anak Krakatau had 340,000 discharges over a week or so.
The astounding amount of lightning wasn’t the only prelude to the volcano’s cataclysmic blast. By Saturday morning, satellite imagery had revealed the island was no longer building itself: The middle of the volcanic isle had vanished, likely thanks to the uptick in explosivity.
When it eventually unleashed a giant explosion, the shockwave ricocheted across the globe at breakneck speeds. It was immediately followed by a tsunami that slammed into several islands in the Tongan archipelago before racing across the Pacific.
Jackie Caplan-Auerbach, a seismologist and volcanologist at Western Washington University in Bellingham, says the blast involved a “mind-boggling amount of energy.” But there isn’t enough data right now to ascertain the precise cause of the tsunami.
These events require displacing a lot of water, which can happen through underwater explosions, through a collapse event—when lots of rock suddenly falls off the volcano into the sea—or a combination of these and other factors.
With the ash column obscuring the volcano, and much of the volcano submerged underwater, scientists will need time to gather more indirect data before drawing any conclusions. Clues could come from the types of acoustic waves the blast generated or perhaps the redistribution of mass around the volcano.
“The jury is still out,” Caplan-Auerbach says, but the fact that such an intense explosion and potent tsunami came out of this single, relatively small volcanic isle “speaks to the incredible power of this eruption.” And although not the cause of the main tsunami, the shockwave itself triggered another big wave: The rapidly moving air impacting the ocean was powerful enough to force water to move out of the way, a phenomenon called a meteotsunami.
The Tongan archipelago may owe its very existence to the infernal forces that constructed its islands in the first place, but it’s clear the cost of living on them can be steep. Only 100,000 people live in the kingdom, with about a quarter residing in the capital, and they are now besieged by ashfall and tsunami waves.
“The biggest unknown right now that really matters is we don’t know how the people in Tonga are,” Krippner says. This eruption, Mitchell adds, “could potentially be incredibly devastating to the country.”
So now comes the question everyone wants answered: “Is this eruption over?” Krippner says. “We don’t know.”
Such a terrifying outburst may represent the effective decapitation the volcano’s shallow magma reservoir and the speedy exsanguination of its molten contents, Mitchell says. This eruption will be extensively studied by volcanologists, which will only improve their understanding of future events and bolster efforts to mitigate their effects.
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Satellite images from JMA show the volcano eruption in Tonga on January 15. JMA Himawari satellite/Japan Meteorological Agency. On social media, footage showed people fleeing as waves...
2022年11月20日 · Tonga's strange volcanic eruption was even more massive than we knew. The ferocious 2021 explosion blew out 2.3 cubic miles of rock, unleashing a 35-mile-high plume and a global tsunami that...
2022年1月19日 · The explosion of the underwater volcano, which is formally known as Hunga Tonga-Hunga-Haʻapai, rained hazardous ash over the region, including the Tongan capital, Nuku’alofa, about 40 miles...
