The eruption of the Tonga volcano was unusual, it could even warm the earth

NEW YORK (Associated Press) – When an underwater volcano erupted in Tonga in January, its watery eruption was massive and unusual — and scientists are still trying to understand its impact.

The volcano, known as Hunga Tonga-Hunga Ha’apai, released millions of tons of water vapor high into the atmosphere, according to the report The study was released on Thursday in Science magazine.

Researchers estimate the eruption increased the amount of water in the stratosphere — the second layer of the atmosphere, above the area where humans live and breathe — by about 5%.

Now scientists are trying to figure out how all that water might affect the atmosphere and whether it will warm the Earth’s surface in the years to come.

“This was a unique event,” said lead author Holger Voemel, a scientist at the National Center for Atmospheric Research in Colorado.

Large eruptions usually cool the planet. Most volcanoes emit large amounts of sulfur, which blocks the sun’s rays, explained Matthew Toohy, a climate scientist at the University of Saskatchewan who wasn’t involved in the study.

The explosion in Tonga was much more powerful: the eruption started under the ocean, raising a column with much more water than usual. Because water vapor acts as a greenhouse gas that traps heat, it’s likely that a volcanic eruption would raise temperatures rather than lower them, Tohey said.

It’s not clear how much warming that could hold.

Karen Rosenloff, a climate scientist at the National Oceanic and Atmospheric Administration who was not involved in the study, said she expects the impact to be limited and temporary.

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“This surge could slightly warm the surface for a short period of time,” Rosenloff said in an email.

The water vapor will linger in the upper atmosphere for a few years before making its way to the lower atmosphere, Tohey said. Meanwhile, Rosenloff added the extra water could accelerate ozone depletion in the atmosphere.

But it’s hard for scientists to say for sure because they’ve never seen an eruption like this before.

Vojmel explained that the stratosphere extends from about 7.5 miles to 31 miles (12 km to 50 km) above Earth and is usually very dry.

Voemel’s team estimated the volcano’s plume using a network of instruments suspended from weather balloons. These instruments typically can’t measure stratospheric water levels because the amounts are too small, Voemel said.

Another research group monitored the explosion using an instrument on a NASA satellite. into their studiesreleased earlier this summer, estimated the eruption would be larger, adding about 150 million tons of water vapor to the stratosphere — three times what the Voemel study found.

Voemel acknowledged that satellite imagery may have noticed parts of the pillar that balloon tools were unable to capture, making their estimate higher.

Anyhow, he said the Tonga eruption was unlike anything seen in recent history, and examining its impact could provide new insights into our atmosphere.


The Associated Press’s Health and Science Division is supported by the Howard Hughes Medical Institute’s Science Education Division. AP is solely responsible for all content.