Scientists claimed to have figured out what caused the massive tsunami that hit Tonga earlier this year and traveled around the world so swiftly.
The extraordinary event was caused by acoustic-gravity waves (AGWs) triggered by the powerful volcanic blast, which traveled into the atmosphere and across the ocean as the Hunga Tonga-Hunga Ha'apai volcano erupted, according to a new paper published today in Nature by an international team including Cardiff University researchers.
Hunga-Tonga eruption
Mary Lyn Fonua/AFP via Getty Images
As these waves collided, energy was constantly injected into the tsunami, causing it to grow larger, move much further, much faster, and for much longer, as per NASA.
On 15 January 2022, the Hunga Tonga-Hunga Ha'apai volcano erupted, becoming the greatest volcanic eruption of the twenty-first century and the largest since Krakatoa in 1883.
It was hundreds of times more powerful than the Hiroshima atomic bomb and was regarded as the largest explosion ever recorded in the atmosphere.
The eruption caused global atmospheric changes as well as an unusually fast-traveling tsunami, which perplexed earth, atmospheric, and ocean experts equally.
The volcano sent a massive cloud of gases, water vapor, and dust into the sky as it erupted.
The explosion also caused significant pressure changes in the atmosphere, which resulted in high winds. Winds became quicker as they extended upwards into smaller atmospheric layers.
ICON detected wind speeds of up to 450 mph as it approached the ionosphere and the edge of space, making them the mission's highest winds below 120 miles altitude since launch.
Electric currents in the ionosphere were also influenced by the strong winds.
The equatorial electrojet is an east-flowing electric current formed by particles in the ionosphere that is driven by winds in the lower atmosphere.
Understanding how this complicated region of our atmosphere responds to powerful influences from below and above is an important element of NASA's study.
NASA's forthcoming Geospace Dynamics Constellation, or GDC, will study electrical currents and atmospheric winds using a band of tiny satellites, similar to weather sensors on the ground.
Scientists can better forecast serious difficulties caused by such disruptions by studying what influences electrical currents in the ionosphere.
Although the theory that tsunamis are caused by airwaves induced by volcanic eruptions isn't new, this occurrence was the first to be recorded by contemporary, global dense equipment, helping experts to finally figure out how these unusual phenomena work, said co-author of the study Dr. Ricardo Ramalho, from Cardiff University's School of Earth and Environmental Sciences.
AGWs are very long sound waves that propagate through space because of gravity's impact, as per ScienceDaily.
They are created by volcanic eruptions or earthquakes, among other powerful causes, and may cut through a medium at the speed of sounds, such as the deep ocean or the atmosphere.
A single AGW can span tens of kilometers and penetrate hundreds of meters into the ocean surface, carrying energy from the top surface to the bottom and throughout the oceans.
AGWs can spread into the atmosphere following catastrophic events like volcanic eruptions and earthquakes, in addition to crossing the ocean, said co-author Dr. Usama Kadri of Cardiff University's School of Mathematics.
The Tonga eruption occurred in an excellent position below the surface, in shallow water, causing energy to be released into the atmosphere in a mushroom-shaped pattern close to the water surface, ensuring that energetic AGWs would impact with the water surface.
The scientists used sea-level, atmospheric, and satellite data from throughout the world at the time of the volcanic eruption to establish that the tsunami was generated by AGWs that traveled quickly into the atmosphere and were continually 'pumping' energy.
