This Could Be Why The Massive Volcanic Eruption in Tonga Was So Explosive
By any measure you want to use, the Hunga Tonga-Hunga Ha'apai volcano eruption in January 2022 was a massive eruption.
It produced a swirling plume of gas, dust and ash that reached 58 kilometers (36 miles) into the sky, atmospheric waves that traveled around the globe several times, and tsunamis in the Caribbean on the other side of the Pacific Ocean.
A newly published study now suggests why the scale of this volcanic blast was so huge: a smaller eruption the day before, priming the volcano for a bigger explosion by sinking its main vent under the surface of the ocean.
That meant molten rock was spewing out straight into seawater, vaporizing it along the way and intensifying the eruption. ...
Combined with ice crystals in the upper atmosphere, the roiling cloud of material built static charges that drove a dramatic period of lightning. The frenzy of electrical activity was so intense, in fact, it represented 80 percent of Earth's lightning strikes in its most active hour.
"We really just set out to try to understand what happened," says volcanologist Melissa Scruggs from the University of California, Santa Barbara. ...
Scruggs and her colleagues think that almost 2 cubic kilometers (0.48 cubic miles) of material – weighing about 2,900 teragrams or 2.9 thousand million metric tons – was sent half way to space, causing violent ripple effects that were felt around the world.
The first two hours of the eruption were particularly violent, the researchers discovered, with the event starting at 5.02pm local time. After about 12 hours, activity at the site faded. It's the largest eruption we've seen since the 1991 blast from Mount Pinatubo in the Philippines, the researchers say. ...