Author of the article: The eruption of an underwater volcano off Tonga, which triggered a tsunami warning for several South Pacific island nations, is seen in an image from the NOAA GOES-West satellite taken at 05:00 GMT, January 15, 2022. Photo by CIRA/ NOAA / via REUTERS
Content of the article
WASHINGTON — The powerful Jan. 15 underwater eruption of Tonga’s Hunga Tonga-Hunga Ha’apai volcano in the South Pacific produced a plume that shot higher into Earth’s atmosphere than any on record — about 35 miles (57 km) — as it stretched more than halfway to space, researchers said Thursday.
Advertisement 2
This ad hasn’t loaded yet, but your article continues below.
Content of the article
The white-gray plume released by the eruption in the Polynesian archipelago became the first documented to have penetrated an icy layer of the atmosphere called the mesosphere, according to scientists who used a new technique using multiple satellite images to measure its height. Sign up to receive The Canucks Report newsletter, delivered directly to your inbox at the start of each series. Essential reading for hockey fans who eat, sleep, Canucks, repeat. By clicking the subscribe button you consent to receive the above newsletter from Postmedia Network Inc. You can unsubscribe at any time by clicking the unsubscribe link at the bottom of our emails. Postmedia Network Inc. | 365 Bloor Street East, Toronto, Ontario, M4W 3L4 | 416-383-2300
Thanks for subscribing!
A welcome email is on its way. If you don’t see it, check your spam folder. The next issue of the Canucks Report will be in your inbox soon. We encountered a problem with your registration. PLEASE try again
Content of the article
The plume consisted mostly of water with some ash and sulfur dioxide mixed in, said atmospheric scientist Simon Proud, lead author of the study published in the journal Science. Eruptions from terrestrial volcanoes tend to have more ash and sulfur dioxide and less water. The deafening explosion sent tsunami waves into the Pacific Ocean and produced an atmospheric wave that traveled several times around the world. (See related chart)
Advertising 3
This ad hasn’t loaded yet, but your article continues below.
Content of the article
“For me, what was impressive is how quickly the explosion happened. It went from nothing to a 57km high cloud in just 30 minutes. I can’t imagine what it must have been like to see it from the ground,” said Proud, a fellow at Britain’s National Earth Observatory who works at the University of Oxford and STFC RAL Space. “Something that fascinated me was the dome-like structure in the center of the umbrella plume. I’ve never seen anything like this before,” added Oxford atmospheric scientist and study co-author Andrew Prata. Damage and loss of life—six deaths—were relatively low due to the blast’s remote location, although it obliterated a small and uninhabited island. Tonga is an archipelago of 176 islands with a population of just over 100,000, located southeast of Fiji and just west of the International Date Line.
Advertising 4
This ad hasn’t loaded yet, but your article continues below.
Content of the article
“It could have been a lot worse,” said Proud. The plume extended through the lower two layers of the atmosphere, the troposphere and stratosphere, and about 4 miles (7 km) into the mesosphere. The top of the mesosphere is the coldest place in the atmosphere. “The mesosphere is one of the upper layers of our atmosphere and it’s generally pretty quiet – there’s no familiar weather up there and the air is very dry and extremely thin,” Proud said. “It’s one of the least understood parts of the atmosphere because it’s so hard to get to. Lower, we can use airplanes. Higher up, we have spaceships. Many meteorites burn up in the mesosphere, and it also hosts nocturnal clouds, which are sometimes visible in the summer sky toward the poles.”
Advertising 5
This ad hasn’t loaded yet, but your article continues below.
Content of the article
The plume was far from reaching the next atmospheric layer, the thermosphere, which starts about 53 miles (85 km) above the Earth’s surface. A demarcation called the Karman line, about 62 miles (100 km) above the Earth’s surface, is generally considered the boundary with space. Until now, the highest recorded volcanic plumes were from the 1991 eruption of Mount Pinatubo in the Philippines at 25 miles (40 km) and the 1982 eruption of El Chichón in Mexico at 19 miles (31 km). Volcanic eruptions in the past likely produced higher plumes, but they occurred before scientists could make such measurements. Proud said the 1883 eruption of Krakatau in Indonesia probably reached the mesosphere. Scientists were unable to use the standard technique of measuring a volcanic plume based on temperature because the January eruption passed the maximum height for which this method could be used. Instead, they turned to three geostationary weather satellites that received images every 10 minutes and relied on what’s called the parallax effect – determining the location of an object by seeing it along multiple lines of sight. “For the parallax approach we’re using to work, you need multiple satellites in different locations – and that’s only become possible on a global scale in the last decade or so,” Proud said. (Reporting by Will Dunham Editing by Rosalba O’Brien)
Share this article on your social network
Advertisement 1
This ad hasn’t loaded yet, but your article continues below.
Comments
Postmedia is committed to maintaining a lively but civil forum for discussion and encourages all readers to share their views on our articles. Comments may take up to an hour for moderation before appearing on the site. We ask that you keep your comments relevant and respectful. We’ve enabled email notifications—you’ll now receive an email if you get a reply to your comment, there’s an update on a comment thread you’re following, or if a user follows the comments. Visit the Community Guidelines for more information and details on how to adjust your email settings.
