On January 15, 2022, the Hunga Tonga-Hunga Ha’apai volcano in the Tonga archipelago erupted, blanketing the neighboring islands in a thick layer of ash. At least three people died.
The force with which the volcano actually erupted is increasingly being documented by data on the event. A working group led by Robin Matoza from the University of California in Santa Barbara, for example, shows in “Science” how often the pressure wave from the explosion raced around the earth: it spread at a speed of around 1100 kilometers per hour and circled the earth at least four times within six days, as the records from thousands of measuring stations around the world show.
According to Matoza and Co, a so-called Lamb wave emerged as the most dominant atmospheric wave that was stimulated by the Tonga eruption. It only occurs in extremely strong, explosive events.
The team compared the data to those of other volcanic eruptions, including that of Krakatoa in 1883. The amplitude of the pressure wave was therefore the magnitude of the Krakatoa eruption and ten times larger than the eruption of Mount St. Helens in 1980.
The effects of the atmospheric pressure wave were also evident in the sea: it triggered meteoric tsunamis worldwide that preceded the geotectonic tsunami wave triggered in the Pacific.
In addition, the Hunga eruption produced what the scientists say was a “remarkable” infrasound wave that has been proven worldwide and a boom that can be heard over 10,000 kilometers away.
The eruption is considered the strongest of the 21st century; its ash clouds even reached the stratosphere. The ejected particles also caused a thunderstorm of lightning that has never been proven before.
Records from Finnish environmental technology group Vaisala show 590,000 lightning bolts in three days around the eruptions, beginning on January 13 and culminating on January 15.
The original to this article “Tonga explosion wave triggered tsunamis and infrasonic wave” comes from Spektrum.de.
