The eruption reached its peak on Jan. 15, 2022. The ocean wave that caused damage as far away as the U.S. West Coast was caused by the rapid release of energy.
The wave pattern close to the eruption was quite complicated, but thousands of miles away it appeared as an isolated wave front.
The b l ast was 500 times more powerful than the bomb dropped on Japan, according to NASA. The wave looked like it came from a stone in a pond.
Dramatic photos show the aftermath of a volcano.
As it moved over North America, India, Europe and many other places, the pulse registered as a change in the atmospheric pressure. Observers posted their barometric observations to social media as people followed the progress of the pulse online. The wave went around the world in 35 hours.
Fascinating depiction of the pressure wave associated with the Tonga eruption as it moved across the US today. RT @akrherz: 15 minute pressure altimeter change via ASOS NWS/MADIS 5 minute interval data. Shows the shockwave from the #Tongaeruption. pic.twitter.com/qdArMC008YJanuary 15, 2022
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I have studied the global atmosphere for almost four decades. The expansion of the wave front from the Tonga eruption was a spectacular example of the phenomenon of global propagation of atmospheric waves.
The atmosphere was ringed like a bell by the powerful eruption, though it was too low to hear. Over 200 years ago, it was a phenomenon.
The eruption of Mount Krakatoa in Indonesia in 1884 was the first pressure wave that attracted scientific attention.
The Krakatoa wave pulse was detected in barometric observations all over the world. Communication was slower in those days, but scientists were able to plot on a world map the propagation of the pressure front in the hours.
The wave front traveled around the globe at least three times. The Royal Society of London published a series of maps showing the propagation of the wave front.
The waves seen after Krakatoa are very low-frequency. The propagation occurs when local pressure changes cause a force on the adjacent air to accelerate, causing an expansion or compression, which in turn forces air farther along the wave.
We expect sound to travel in straight lines from an exploding firework to the ear of the onlooker. The global pressure pulse has a peculiarity of bending as they follow the Earth's curve.
There are 10 incredible volcanoes in our solar system.
Pierre-Simon de Laplace predicted such behavior over 200 years ago.
Laplace's theory was based on the physical equations governing atmospheric motions. He predicted that there should be a group of motions in the atmosphere that hug the surface of the Earth. One effect is to allow atmospheric waves to follow the Earth's curve, because the forces of gravity and atmospheric buoyancy favor horizontal air motions.
This was a somewhat abstract idea for most of the 19th century. The pressure data after the eruption of Krakatoa showed that Earth-hugging motions can be excited and will travel over enormous distances.
Understanding this behavior can be used to detect nuclear explosions. The full implications of Laplace's theory for the background vibration of the global atmosphere have only recently been confirmed.
An eruption that sets the atmosphere ringing like a bell is one example of the phenomenon that Laplace theorizes. The same phenomenon is also present in the atmosphere.
The global oscillations, similar to the way water moves in a bathtub, have only recently been detected.
Waves propagating through a musical instrument, such as a violin string, drum skin or metal bell, can connect the atmosphere rapidly over the whole globe. The atmosphere can ring at a set of frequencies.
I was able to use modern observations to confirm the implications of Laplace's theory in 2020. We were able to spot the global patterns and frequencies that Laplace and others who followed him had theorized by analyzing a newly released dataset of atmospheric pressure every hour for 38 years at sites worldwide.
The global atmospheric oscillations are too low-frequency to be heard, but they are excited continuously by all the other motions in the atmosphere, providing a very gentle but persistent background music.
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