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When the Hunga Tonga-Hunga Ha’apai volcano erupted underwater in January, it created a plume of ash and water that tore through the third layer of Earth’s atmosphere.
It was the highest recorded volcanic plume and reached the mesosphere, where meteorites and meteorites normally break up and burn in our atmosphere.
The mesosphere, about 31 to 50 miles (50 to 80 kilometers) above the Earth’s surface, troposphere and stratosphere and below the other two layers. (Stratosphere and mesosphere are dry atmospheric layers.)
The highest point of the volcanic plume reached an altitude of 35.4 miles (57 kilometers). It surpassed previous records, such as the 1991 eruption of Mount Pinatubo in the Philippines at 24.8 miles (40 kilometers) and the 1982 eruption of El Chichon in Mexico at 19.2 miles (31 kilometers).
The researchers used satellite images of the eruption site to confirm the height of the plume. The eruption occurred on January 15 in the South Pacific Ocean, near the Tonga archipelago, in an area covered by three geostationary weather satellites.
A study detailing the findings was published Thursday in the journal Science.
A strong plume was felt in the upper layers of the atmosphere There was enough water to fill 58,000 Olympic-sized swimming poolsAccording to previous NASA satellite detections.
Understanding the height of the plume can help researchers study the impact of the eruption on global climate.
It was difficult for researchers to determine the height of the plume. Typically, scientists can measure the height of a plume by studying its temperature — the colder the plume, the higher it is, said lead study co-author Dr. Simon Proud is a researcher at RAL Space and the National Center for Earth Observation and the University of Oxford.
However, this method could not be applied to the Tonga event because of its violent eruption.
“The eruption pushed the layer of atmosphere we live in, the troposphere, into the upper layers where the atmosphere warms again as you go up,” Proud said via email.
“We had to come up with another approach, using different views from weather satellites on opposite sides of the Pacific Ocean and some pattern matching techniques to determine the height. “This has only become possible in recent years, as even a decade ago we didn’t have the technology of satellites in space to do this.”
Citing the “parallax effect” to determine the height of the plume, the research team compared how the plume looks from different angles as photographed by meteorological satellites. The satellites took pictures every 10 minutes, documenting dramatic changes in the plume as it rose from the ocean. The images showed differences in the position of the plume from different lines of sight.
The eruption “went from nothing to a 57 kilometer tower of ash and clouds in 30 minutes,” Proud said. Team members also observed rapid changes at the top of the eruptive plume that surprised them.
“After the initial big burst, which reached 57 kilometers, the central dome of the plume collapsed inward, shortly after another plume appeared,” Proud said. “I didn’t expect something like this to happen.”
The amount of water released by the volcano into the atmosphere is expected to temporarily warm the planet.
Co-author of the study Dr. Andrew Prata, Postdoctoral Research Assistant in the Atmospheric, Oceanic and Planetary Physics Sub-Department of the Clarendon Laboratory at the University of Oxford, via email.
Knowing the composition and height of the plume can reveal how much ice is felt in the stratosphere and where ash particles are released.
Altitude is also critical to aviation safety, as volcanic ash can cause engine failure, so it’s important to prevent ash plumes from forming.
The height of the plume is another emerging detail of what is known as one of the most powerful volcanic eruptions on record. When the undersea volcano erupted 40 miles (65 kilometers) north of Tonga’s capital, it triggered a tsunami and shock waves that rippled around the world.
Investigations are ongoing to find out why the eruption was so powerful, but it may have occurred underwater.
The heat of the eruption vaporized the water and “created a steam explosion that was more powerful than a volcanic eruption would normally be,” Proud said.
“Examples such as the Hunga Tonga-Hunga Ha’apai eruption show that magma-seawater interactions play an important role in generating highly explosive eruptions that can propel volcanic material to extreme heights,” Silver added.
Next, researchers want to understand why the plume is so high, as well as its composition and its lasting impact on the global climate.
“Often when people think of volcanic plumes, they think of volcanic ash,” Silver said. “However, preliminary work on this case reveals that there is a significant amount of ice in the plume. “We also know that fairly small amounts of sulfur dioxide and sulfate aerosols were produced quickly after the eruption.”
Proud wants to use multi-satellite altimetry techniques in this work to create automatic warnings for severe thunderstorms and volcanic eruptions.
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