Tonga Eruption

[Nev]

You could believe that about Krakatau bursting eardrums, based on the video of the Hunga Tonga-Hunga Ha'api eruption wave coming through - the sound was very sharp and very loud indeed. Makes me wonder what Taupo would sound like, albeit only with a lake above it and not an ocean.

Great article there Nev.

Please consider that "The Video" is not of the actual event. Same can be said of the small Tsunamis rolling in. It was the build up and early on at that. As things ramped up from there, The ash cloud turned day in to night and most residents moved to higher ground (Look and you'll find videos of this). The actual explosion proper was later in the peace & I've to date seen no video of it.

The media seem to think that video was the sound of the main eruption, which occurred at 5:15pm on Saturday (NZ & Tonga local time) according USGS. The first tsunami waves arrived in the capital, Nukuʻalofa about 15 minutes later, according to news reports, the largest being 1.2 metres recorded at 5:30pm according the BoM's tsunami bulletin. From what I've seen, it doesn't look like the ash cloud 'turned day to night' in Nukuʻalofa until a little later at around 6pm.

There were some small tsunamis reported from the previous day's eruptions, but no larger than about 30cm. The local journalist who videoed the first tsunamis after Saturday's main eruption also said they couldn't see the eruption itself that day because of the 'whiteout on the horizon'.

Video captures enormity of shockwave boom after Tonga eruption
https://www.1news.co.nz/2022/01/15/tong ... -eruption/

Journalist based in Tonga describes ‘huge’ volcanic explosions
https://www.1news.co.nz/2022/01/15/jour ... xplosions/

Footage shows Tongan drivers try to flee tsunami wave
https://www.1news.co.nz/2022/01/15/foot ... nami-wave/

[Chris Raine]

The noise heard at Thornbury in Southland were two distinct bangs. The house shook with each bang .Neighbour's popped out of their houses wondering what they had heard as well. Calm clear night

[jamie]

We heard frequent and ongoing bangs for about 45 min starting not long after 7pm. Then it went quiet for maybe 20 mins then we got some real big ones about an hour after it first started. These were some of the biggest thuds. Some made the house rattle and shake. At one point it was non stop noise. Almost like hail roar in USA or the grand finale of big time fireworks.
Around 7pm I went outside to see if I would hear or see the shock wave. I felt my ears hurt and I thought na I’m just imagining they are hurting. There is no way this is the volcano. Then very shortly later the bangs started. I had put the kids to bed a few mins before 7 and then went outside. I totally thought the kids were Making the banging noises. I said to my wife, “which bloody kids are jumping off their bed”. It took maybe 15 mins to click to what we were hearing and why my ears had hurt for maybe 30 seconds a while earlier.


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[BeaconHill]

Really interesting article about the atmosphere-tsunami coupling effects observed around the Pacific following the eruption. Explains why waves were observed to be bigger when they arrived in Japan, compared to what was predicted AND observed hours earlier when they passed mid pacific islands.
It is Japanese, but I found if you open in iOS on an iPhone you can use Apple translate to get a good enough translation to read it.

https://www.nhk.or.jp/kaisetsu-blog/100/459802.html

Would also explain why small tsunami-like fluctuations were reported in the Caribbean!

[tgsnoopy]

Really interesting article about the atmosphere-tsunami coupling effects observed around the Pacific following the eruption. Explains why waves were observed to be bigger when they arrived in Japan, compared to what was predicted AND observed hours earlier when they passed mid pacific islands.
It is Japanese, but I found if you open in iOS on an iPhone you can use Apple translate to get a good enough translation to read it.

https://www.nhk.or.jp/kaisetsu-blog/100/459802.html

Would also explain why small tsunami-like fluctuations were reported in the Caribbean!

Thanks for that

Google translate handled it quite well too. Throw the URL above in to the left panel...

https://translate.google.co.nz

[Chris W]

An update today from GNS via RNZ on the initial assessments of the volume of material ejected and also the distance of the audible eruption noise, as well as some comments on the tsunami:
https://www.rnz.co.nz/news/national/459 ... om-volcano

[jamie]

I picked up more pressure anomalies yesterday morning around sun rise and yesterday afternoon. Small but noticeable.


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[Richard]

Been a few minor fluctuations since the first major pressure wave here also.

Screenshot 2022-01-21 at 19-47-25 Neon System.png

[Chris Raine]

Noticed that too,a Pressure fluctuation at 0400 yesterday morning on my barograph

[BeaconHill]

A more detailed first hand video of the eruption taken from 73km away. Shows how violent the atmospheric pressure waves were, even creating a hole in the ceiling! He could even tell when the next wave was going to hit. Also the suction effect of the clouds due to the uplift from the eruption.

Very interesting watch!!

https://youtu.be/vn1Gfqd6SK4

[jamie]

Amazing. Thanks for sharing.


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[Nev]

Great video there!

Below is also a short time-lapse video taken from the Hawaiian Observatory, which shows the faint atmospheric pressure waves running perpendicular to the high clouds (best viewed on a large screen).



And if you've got a spare 24 minutes, this compilation of local Tongan cellphone footage at the time of the main blasts is also worth a look.

[Awhituobs]

wow, that is what we could hear, but obviously only faintly and more muffled!

[Razor]

That must have been freaking terrifying

[BeaconHill]

Follow up video from the YouTuber who posted the video of the “effects of the eruption on the first day”.

This video starts the next day and documents some of the hassles and effort that had to put into the clean up effort. A massive community effort. And highlights how things like water and power can be so affected by an eruption. (Ruapehu alert level anyone? )

https://youtu.be/COIWqvSJoHM

[BeaconHill]

Another interesting article on the eruption and how it impacted the very upper levels of the atmosphere.
https://www.nasa.gov/feature/goddard/20 ... ched-space

[TonyT]

https://www.nature.com/articles/s41586- ... 680a1c0e0c

[BeaconHill]

https://www.nature.com/articles/s41586- ... 680a1c0e0c

Apparently that article will be made "free to view" at some stage according to the writers (Twitter: @CorwinWright and @CathyClerbaux)

In the mean time, they have tweeted a link to the video (3mins long) associated with the research:
https://www.youtube.com/watch?v=NCyg9GLq61g
"Surface-to-space atmospheric waves from Hunga Tonga eruption.

Eruption of Hunga Tonga-Hunga Ha’apai on 15 January 2022 was unique in observed science, creating waves that reverberated around the earth and reached 100km into the ionosphere."

[tgsnoopy]

Some good articles in the latest Air Force news.

https://issuu.com/nzdefenceforce/docs/a ... s_issue244

[James]

I'm surprised that no one has connected the link between the cooling effect in the atmosphere over the tropics, combined with the warmer water, and the resulting "atmospheric rivers" that we have been having since January. The media have mentioned the brilliant sunsets in NZ and Antarctica, but causing weather doesn't suit the agenda
I worry a bit about what will happen when the tropical season kicks in.....

[Awhituobs]

there was not enough ash to have any noticeable cooling effect
instead though there was extra water vapour ejected into the upper atmosphere
its that which has caused the light scattering and so sunset/sunrise colours
(and since water vapour is a green house gas, its actually not going to cause cooling)

[James]

Ah, but it would cut down some of the normal heating from the big yellow ball in the sky?

[Awhituobs]

not really I would suggest
there is not actually much water vapour in the upper atmosphere (25km+).,.as its very thin air anyway...and very cold (and so very dry) ...but, it has been doubled..by the eruption...but its still not much.,.(even at the surface

BUT
when the sun angle is very low, i.e well after sunset, and the light rays are shinning up into and through the upper atmosphere (25km and higher)
the doubling of the water vapour is causing more scattering than normal of that light, producing colours not normally seen (purples, oranges etc)
i,e so its more of a visual change
there is some concern about what that extra water vapour is doing to the ozone layer though


https://www.albany.edu/faculty/rgk/atm101/structur.htm

[James]

In my sixty years of watching the weather, I do not remember ever witnessing these continual "atmospheric rivers" such as we have had since January. I do fear for the upcoming cyclone season.

I hope I'm wrong.

[Awhituobs]

a triple dip la nina and indian ocean dipole combined is fueling this
but yes Summer could very likely see continuing heavy rain events