February 26, 2024

Tonga’s Hunga volcano erupted on January 15, 2022, lasting at least 11 hours and producing a record amount of lightning. The information collected on eruptions can be used to better monitor aviation-related hazards caused by such eruptions.

Hunga in the South Pacific is an undersea volcano. The volcano began rumbling in December 2021, and its explosive activity intensified on Jan. 13, 2022, peaking two days later when it spewed ash, water and lava gas into the mesosphere at least 36 miles (58 kilometers) away.

While the massive plume they observed at the time gave researchers some idea of ​​the scale of the eruption, it wasn’t until they looked at high-resolution data from four different sources that they really understood the timing of the eruption and its impact .

“This eruption triggered a super-intense thunderstorm that we’ve never seen before,” said Alexa Van Eaton, lead author of the study. “These findings demonstrate that we must have a new tool to monitor volcanoes at the speed of light and help the USGS (American Geological Society) in its role of ash hazard advisories to aircraft.”

Relying on data from sensors that measure light and radio waves, the researchers tracked the lightning and estimated their height. They found that the Hunga eruption produced more than 192,000 flashes of nearly 500,000 electrical pulses. The flashes peaked at 2,615 times per minute and reached altitudes of 12 to 19 miles (20 to 30 kilometers) high, which had never been seen before.

“With this eruption, we found that volcanic plumes can create conditions for lightning far beyond the range of meteorological thunderstorms we’ve previously observed,” Van Eaten said. “It turns out that volcanic eruptions produce more extreme lightning than any other type of storm on Earth.”

The volcano’s plume pushed so much material into the mesosphere that it created waves in the volcanic cloud, like ripples in a pond when a stone is dropped. Lightning has been seen “surfing” these waves, moving outward in a massive 150-mile (250-kilometer) circle.

“It wasn’t just the intensity of the lightning that attracted us,” Van Eaten said. “The size of these lightning rings blew our minds. We had never seen anything like this before, and there was no comparison in meteorological storms. Single lightning rings were observed, but not multiple, and they were small in comparison.”

Obtaining reliable information about volcanic plumes at the onset of an eruption can be challenging, especially from submarine volcanoes. Insights from the Hunga eruption could be used to better monitor aviation-related hazards during future large eruptions, researchers say.

This is the first time modern instruments have been used to observe massive magma spewing water, known as a phreatoplinian eruption. So far, scientists have only seen evidence of reef eruptions in the geological record.

“It’s like digging up a dinosaur and seeing it walk around on four legs,” Van Eaton said. “It kind of takes your breath away.”

The study was published in the journal Geophysical Research Letters, The video below, produced by the American Geophysical Union (AGU), shows the meteorological impact of the Hunga eruption.

Tonga’s Hanga Volcano Generates Strongest Lightning Ever

source: AGU