25 January 2022
In case you missed it …
The archipelago of Tonga was devastated on 15 January 2022 when one of its islands exploded violently around 4pm local time. The capital city of Nuku’alofa, only 41 miles away, was hard hit by the shock wave, tsunami and heavy ash fall.
When the dust cleared the island of Hunga Tonga-Hunga Ha’apai had disappeared leaving just two small remnants.
This NASA composite of eight GOES-17 satellite images shows just the first hour and 20 minutes of the massive explosion.
The explosion that killed the island was more violent than a nuclear bomb. Its sound was heard in Alaska, its tsunami rippled through the Pacific, Atlantic, Caribbean and Mediterranean, and its atmospheric shock wave sped at 1,000 feet/second (681 mph) around the world.
Atmospheric scientists immediately began crunching the numbers. By 19 Jan, Nedjeljka Žagar (@NedjeljkaZ) of the University of Hamburg, tweeted this map with a request for verification.
How good does this simulation of the wave generated by the Hunga Tonga-Hunga Ha?apai eruption fit with your local surface pressure measurements? We see a good agreement with pic.twitter.com/wZMNf97EUh, etc
— Nedjeljka Žagar (@NedjeljkaZ) January 19, 2022
Performed by Sergiy Vasylkevych at @CENunihh. (1/4) pic.twitter.com/WNS1rkpukt
On 21 Jan, EOS published more information on the Surprising Reach of Tonga’s Giant Atmospheric Waves including Nedjeljka Žagar’s animation of the shock wave across the globe, embedded below.
The outbound wave passed over Pittsburgh at approximately 10:30am on Sat 15 Jan, converged to a single point over northern Africa — probably at the explosion’s antipodes, GPS 20.545003 4.609298, Guezzam, Algeria — crossed over itself and headed back again. The return wave passed over us around 9:30p that same day.
You can see it tickle the U.S. in this tweet from Daryl Herzmann @akrherz:
15 minute pressure altimeter change via ASOS NWS/MADIS 5 minute interval data. Shows the shockwave from the #Tongaeruption , feel free to use as you wish. pic.twitter.com/P31Aq1SYku
— daryl herzmann (@akrherz) January 15, 2022
Amazingly the death of a small uninhabited island was felt around the world.
A few of the resources used in this article:
- EOS: The Surprising Reach of Tonga’s Giant Atmospheric Wave
- NASA Earth Observatory: Hunga Tonga-Hunga Ha’apai Erupts
- CIMMS blog: Explosive eruption of the Hunga Tonga volcano
- New York Times: Here’s What Scientists Know About the Tonga Volcano Eruption
- BBC: Tonga eruption: How its impact spread so widely and violently
(photos and gifs credited in the captions; click on the captions to see the originals)
This is an incredible article of information, Kate. Thanks. I did know about it and read some of the stories on it, but none as comprehensive as this.
This is fascinating. Thank you. I read about the very resilient and prepared Tongans, some of whom climbed trees to avoid being washed away.