Tonga volcano was the first ever to send debris into the mesosphere

By Al Mayadeen English
Source: Agencies
21 Nov 09:16

The Hunga Tonga-Hunga Ha'apai volcano erupted underwater in January and the debris has been in the atmosphere for months.

Geologist observing as the volcano erupted (Tonga Geological Services)

A team of scientists led by New Zealand said Monday that the catastrophic volcanic explosion in Tonga in January was the greatest ever observed using current technology.

In the Pacific Island Kingdom of Tonga, the Hunga Tonga-Hunga Ha'apai volcano erupted underwater with the force of hundreds of atomic bombs, causing a 15-meter tsunami that destroyed homes and claimed at least three lives.

The natural disaster also hampered attempts to aid the victims by damaging underwater communication cables that cut Tonga off from the rest of the world for weeks.

The volcano blew out almost 10 cubic kilometers of material, which is equal to 2.6 million Olympic-sized swimming pools according to a thorough study by New Zealand's national institute for water and atmospheric research.

The eruption further fired debris more than 40 kilometers into the mesosphere, the level above the Earth's stratosphere, and Kevin Mackay, a marine geologist, indicated that "the eruption reached record heights, being the first we've ever seen to break through into the mesosphere," adding that "it was like a shotgun blast directly into the sky."

One of the biggest since Krakatoa

The Hunga Tonga-Hunga Ha'apai eruption is comparable to the notorious Krakatoa tragedy, which occurred in Indonesia in 1883 and claimed tens of thousands of lives before the development of modern measurement technology.

"While this eruption was large -- one of the biggest since Krakatoa -- the difference here is that it's an underwater volcano and it's also part of the reason we got such big tsunami waves," Mackay added.

Approximately two cubic kilometers of particles, which lingered in the atmosphere for "months, causing the stunning sunsets we saw," according to Mackay, were thought to have been confined in the plume, which spread as far away as New Zealand in the Pacific.

Additionally, his team found that the volcano's crater had receded 700 meters. Debris from the volcano was carried along the ocean floor at least 80 kilometers away by the eruption's pyroclastic flows, which are deadly currents of lava, volcanic ash, and gases that can reach temperatures of 1,000 degrees Centigrade (1,800 degrees Fahrenheit) and speeds of 700 kilometers per hour.

The team's principal scientist Emily Lane explained that the volcano's "pyroclastic flows appear to extend beyond that, perhaps as far as 100 kilometers away," adding that "the sheer force of the flows is astonishing -- we saw deposits in valleys beyond the volcano, meaning they had enough power to flow uphill over huge ridges and then back down again."