An underwater volcano that erupted earlier this year is believed to be the “largest ever recorded” with modern equipment, researchers revealed this week.
On January 15, 2022 the Hunga Tonga-Hunga Ha’apai volcano erupted in the Tongan archipelago, triggering tsunami waves and sending a sonic boom that could be heard throughout the world. Since then, a team of scientists have been investigating the historic eruption, concluding that it turned out to be one for the record books.
“The eruption reached record heights, being the first we’ve ever seen to break through into the mesosphere,” said New Zealand National Institute for Water and Atmospheric Research (NIWA) marine geologist Kevin Mackay. “It was like a shotgun blast directly into the sky,” he added.
“It was a shotgun blast directly into the sky”. 💥
NIWA scientists have confirmed January’s eruption of the Hunga Tonga-Hunga Ha’apai volcano was the largest ever recorded with modern technology. 🌋
— NIWA (@niwa_nz) November 21, 2022
The eruption in the South Pacific Ocean displaced 10 cubic kilometers of seafloor, which is equal to 2.6 million Olympic sized swimming pools, according to the NIWA. According to their findings, 75% of that material ended up within 20 kilometers of the volcano, meaning much of it remains unaccounted for.
“The volume of this ‘shotgun’ plume is estimated to be 1.9 [cubic kilometers] of material, which has been circulating in our atmosphere for months, causing the stunning sunsets we saw following the eruption,” Mackay said. The group added that the volcano’s caldera, or crater, is now 700 meters deeper than it was prior to the eruption.
NASA Earth Observatory says that the blast from the volcanic eruption “released hundreds of times the equivalent mechanical energy” of the atomic bomb dropped over the Japanese city of Hiroshima. The powerful blast was heard all the way in Alaska, 6,000 miles away.
.@NASAEarth scientists are tracking the effects of the Jan. 15 volcanic eruption in Tonga and sharing satellite data with disaster response agencies: https://t.co/LKO6BWlFkq pic.twitter.com/6KhVMImRh3
— NASA (@NASA) January 20, 2022
Pyroclastic flows, which were said to be one of the great unknowns from the eruption, “are currents made up of dense lava, volcanic ash, and gases which can reach temperatures of 1,000 [degrees celsius] and speeds of 700km/hr,” according to NIWA. Researchers collected 150 sediment cores that were sent to the University of Otago in New Zealand and the National Oceanographic Center in the United Kingdom, revealing deposits up to 80 kilometers away from the volcano.
These are the first pyroclastic flows of this magnitude, according to Mackay. “It’s the interaction with water that made this event so unprecedented. It’s still speculation but the latest science shows that this phenomenon may be more exaggerated under water,” he said.
🧵 Here are some amazing facts about the eruption ⬇️
🌋 Most of the material was deposited within 20kms of the volcano. But more than three cubic kilometres appears to have been shot up to 58km into the sky – causing the stunning sunsets we’ve been seeing.
📸 Pununu Tukuafu pic.twitter.com/QoYKhXF22X
— NIWA (@niwa_nz) November 21, 2022
The tsunami waves that were created by the blast reached 15 meters high when they hit parts of Tonga, devastating the small South Pacific kingdom and leaving it covered in volcanic ash. 1,500 people were displaced and four were killed throughout the Tongan islands, according to the United States Geological Survey, who also noted that damage was recorded in Fiji, Hawaii, Chile, New Zealand, Japan, Russia, and California.
“While this eruption was large – one of the biggest since Krakatoa in 1883 – there have been others of similar magnitude since then that didn’t behave in the same way,” Mackay said, adding that “the difference here is that it’s an underwater volcano and it’s also part of the reason we got such big tsunami waves.”