A deadly volcanic eruption near Tonga in January was the largest ever recorded using modern equipment, a New Zealand team of scientists revealed on Monday.
The Hunga Tonga-Hunga Ha’apai volcano erupted underwater with a force equivalent to hundreds of atomic bombs, triggering a 15-meter (50-foot) high tsunami that destroyed homes and at least three people on the Pacific island kingdom killed.
The natural disaster also damaged underwater communication cables, cutting Tonga off from the rest of the world for weeks and hampering efforts to help victims.
A detailed study by New Zealand’s National Institute for Aquatic and Atmospheric Research shows that the eruption ejected nearly 10 cubic kilometers of material – the equivalent of 2.6 million Olympic-sized swimming pools – and hurled debris more than 40 kilometers (25 miles) into Earth’s mesosphere, the plain above the earth’s stratosphere.
“The eruption reached record highs and was the first we’ve ever seen to penetrate the mesosphere,” said marine geologist Kevin Mackay.
“It was like a shotgun blast straight into the sky.”
The Hunga-Tonga-Hunga-Ha’apai eruption rivals the infamous Krakatoa disaster that killed tens of thousands in 1883 in Indonesia before the invention of modern measuring devices.
“Although this eruption was large — one of the largest since Krakatoa — the difference here is that it’s an underwater volcano, and it’s also one of the reasons we got such big tsunami waves,” Mackay added .
The team of scientists has identified three quarters of the material fired by the Tonga eruption, while the remainder has been explained as debris scattered in the atmosphere.
Mackay said the cloud was estimated to contain almost two cubic kilometers of particles that “remained in the atmosphere for months and caused the stunning sunsets that we saw” over the Pacific region as far north as New Zealand.
His team also discovered that the volcano’s crater is now 700 meters deeper than it was before.
The eruption’s pyroclastic flows — deadly streams of lava, volcanic ash, and gases that reach temperatures of 1,000 degrees Celsius (1,800 degrees Fahrenheit) and speeds of 700 kilometers per hour — carried debris from the volcano along the sea floor at least 80 kilometers away.
“But the pyroclastic flows appear to extend beyond that, perhaps as far as 100 kilometers away,” said the team’s lead scientist, Emily Lane.
“The sheer power of the currents is amazing – we saw deposits in valleys beyond the volcano, meaning they had enough force to flow up giant ridges and then down again.”
