Unidentified Shockwave Hours After Tonga Volcano Eruption... What Is Happening to Earth? [Reading Science]

An underwater volcanic eruption in Tonga captured by a satellite belonging to the U.S. National Oceanic and Atmospheric Administration (NOAA). Photo by Nature.

[Asia Economy Reporter Kim Bong-su] Just hours after the largest underwater volcanic eruption in history occurred on the 15th in Tonga in the South Pacific, a massive shockwave was detected in the airspace above, leaving scientists puzzled as they try to identify its nature, according to the international academic journal Nature on the 19th.

During the Tonga underwater eruption, an unusual pattern of atmospheric gravity waves was observed, which had never been detected in any previous volcanic eruptions, causing confusion among scientists. These waves were detected several hours after the Tonga underwater volcanic eruption by NASA's Atmospheric Infrared Sounder (AIRS) aboard an ocean observation satellite. The waves extended rapidly as dozens of concentric circles over 16,000 km in the atmosphere. They reached from the sea surface up to the ionosphere and are estimated by experts to have possibly circled the Earth multiple times. Particularly, atmospheric gravity waves occur when air molecules are disturbed vertically rather than horizontally, which adds to the mystery.

Theoretically, when hot air and volcanic ash are rapidly ejected due to magma eruption, very large-scale gravity waves can be generated. However, Professor Corwin Wright, an atmospheric physicist at the University of Bath in the UK, said, "Since observations began in 2002, there have been several volcanic eruptions, but such gravity waves have never been observed," adding, "Something physical is definitely happening, but currently, we do not know what it is."

Nature reported, "Professor Wright and colleagues believe that the hot and massive volcanic ash gas mass formed in the upper atmosphere after the eruption may have continued to rise into the stratosphere, generating strong waves."

Meanwhile, NASA also released footage taken during the Tonga underwater volcanic eruption on the same day. NASA stated, "Due to the powerful volcanic eruption, the small uninhabited island known as Hunga Tonga-Hunga Ha'apai in the South Pacific disappeared," and "Worldwide tsunamis, sonic booms, and atmospheric shockwaves occurred." NASA particularly noted, "(The eruption) generated shockwaves and a massive umbrella cloud with a maximum diameter of 500 km," adding, "The cloud size is comparable to that of the Pinatubo volcano, the largest volcanic eruption in history, and matches the widest range observable by satellites."

However, NASA analyzed that this volcanic eruption is unlikely to affect the climate. Approximately 0.4 teragrams of sulfur dioxide were injected into the upper atmosphere by this eruption, but at least 5 teragrams are required to impact the climate.