Australia and New Zealand issue tsunami warnings after South Pacific undersea volcano erupts off Tonga

A tsunami warning is in place for much of Australia's east coast after an explosion at an underwater volcano near Tonga. 

The Tonga Meteorological Services said a tsunami warning had been put in force for all of Tonga (Photo: Dr Faka’iloatonga Taumoefolau)

The Bureau of Meteorology said the Hunga Tonga-Hunga Ha'apai volcano erupted at 3.10pm AEDT on Saturday, and tsunami waves have been observed as a result of the eruption.

Tsunami warnings were issued across much of the Pacific, including New Zealand, Canada, the US and Australia's Lord Howe, Norfolk and Macquarie islands.

Witnesses in Tonga said the blast shook the earth for several minutes and sounded like rumbling thunder.

Video filmed by locals shows waves more than a metre high crashing into houses.

Photos showed ash falling from the sky.  

In Vanuatu, the authorities have received reports of waves up to two-and-a-half metres high.

Tsunami waves nearing 1 metre have been recorded on the Australian mainland.

"The size of these waves means the threat is for the marine environment for the east coast of Australia, and for land on Lord Howe Island and Norfolk Island; however the situation will be closely monitored and warnings updated as required," the BOM said in a statement.

"People in land-warning zones are strongly advised to move 1 kilometre inland or go to high ground at least 10 metres above sea level.

"While evacuations are not necessary for marine warning zones, people in these areas are advised to leave the water and move away from the immediate water's edge."

The statement said tsunami waves are more powerful than beach waves of the same size.

"There will be many waves and the first wave may not be the largest," it said.

The BOM issued marine warnings for parts of Queensland, New South Wales, Victoria and Tasmania.

  • QLD: Sandy Cape to Point Danger
  • NSW: All coastal areas
  • VIC: Lakes Entrance to Gabo Island
  • TAS: Flinders Island to South East Cape

Early on Sunday morning, the NSW State Emergency Service (SES) ordered evacuations of low-lying parts of Lord Howe Island.

Big waves on Gold Coast and Twofold Bay

According to the BOM, large waves have been observed on Australia's east coast, with Queensland's Gold Coast seeing waves of up to 0.82 metres and Twofold Bay in southern NSW recording 0.77 metre waves.

Norfolk Island has observed waves of up to 1.27 metres. 

Tsunami impacts of unusual currents and waves have also been recorded at Lord Howe Island and Derwent Park in Hobart. 

New Zealand warning for north and east coasts

New Zealand's emergency management agency issued an advisory on tsunami activity for its north and east coasts.

The areas, some 2,300 kilometres from Tonga's volcano, were expected to experience strong and unusual currents, and unpredictable surges at the shore.

The Tonga Meteorological Services said a tsunami warning had been put in force for all of the island nation.

Fiji issued a tsunami warning, urging residents to avoid the shorelines "due to strong currents and dangerous waves".

Tsunami waves measuring 60 centimetres in height were also observed by sea-level gauges at the capital of American Samoa, Pago Pago, following volcanic activity in Tonga, the US-based Pacific tsunami warning centre said.

The tsunami threat continues and sea-level fluctuations and strong ocean currents pose hazards along beaches in harbours, the tsunami monitor said in a statement.

The US National Tsunami Warning Center has issued a tsunami advisory for Hawaii and the north-west US, which includes the states of Alaska and California.

Several hours later, a tsunami advisory was issued for Washington state on the north-western US coast, which includes the major city of Seattle. 

'Loud thunder' heard in Fiji

Lasting eight minutes, the eruption could be heard as "loud thunder sounds" in Fiji, more than 800km away, officials in the capital Suva said.

Jese Tuisinu, a television reporter at Fiji One, posted a video on Twitter showing large waves washing ashore with people trying to flee in their cars.

"It is literally dark in parts of Tonga and people are rushing to safety following the eruption," he said.

The eruption, located about 65 kilometres north of Nuku'alofa, caused a tsunami measuring 1.2 metres, the BOM said.

In this satellite image taken by Himawari-8, a Japanese weather satellite, shows an undersea volcano eruption at the Pacific nation of Tonga (Photo: Japan Meteorology Agency)

The federal government is "monitoring the situation and "ready to provide support to Tonga if requested".

"Tonga is part of our Pacific family and our thoughts are with the entire community dealing with the impact of the volcanic eruption and tsunami," a Department of Foreign Affairs and Trade spokesperson said.

"Initial assessments are still underway and DFAT is working to ensure Australians in Tonga are safe and accounted for."

The Japan Meteorological Agency has also issued tsunami warnings for the eastern coastal regions, with waves of 1.2 meters reaching Amami Island in the south of the country.

© Australian Broadcasting Corporation. All rights reserved.

Comments

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:02am

Thought I'd copy over some of my comments from the forum thread which I started last night.

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:03am

Holy shit, just realised that I heard the sonic booms from the volcanic eruption in Tonga, I was on the balcony cooking dinner on the BBQ and heard/felt a quiet rumble that genuinely made put down the tongs, and walk out on to the street. Seemed to be what I imagine a small earthquake might sound like, but without any movement. A second one happened about a minute later. Couldn’t work out what it was, then got distracted. Unsure of the exact time but between 6:30 - 7pm I reckon.

seaslug's picture
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seaslug Sunday, 16 Jan 2022 at 9:40am

Holy sht indeed, thats incredible Ben

Sprout's picture
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Sprout Sunday, 16 Jan 2022 at 11:32am

Not taking into account whatever variables are involved like wind, temperature etc.
Distance 3250k's / speed of sound @ 20'c, 1235k/hr = Roughly 2 hours 40 minutes to hear it at Tweed (plus an hour of variables), crazy. I wonder if you can figure out a rough dB from time, speed and distance.

Anyway, awesome stuff Ben.

Queef Jerky's picture
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Queef Jerky Sunday, 16 Jan 2022 at 8:41pm

Is that accounting for the air speed of an african swallow?

Spuddups's picture
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Spuddups Monday, 17 Jan 2022 at 6:16am

They're non migratory though.

SGAG's picture
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SGAG Sunday, 16 Jan 2022 at 12:21pm

I heard them as well and went outside thinking there must be a thunder about but there wasn't anything in the vicinity.. I'm in Southeastern Tassie!

Crab Nebula's picture
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Crab Nebula Sunday, 16 Jan 2022 at 2:45pm

Wow! Incredible. We heard a strange sound early evening in the back hills of Tweed. We couldnt place it. But, it was like a thump on the roof, short and sharp.

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:03am

Yep, check hPa readings at coastal weather stations around this time, confirms the sonic boom. Byron dropped 6hPa between 6:17pm and 6:48pm.

http://www.bom.gov.au/products/IDN60801/IDN60801.94599.shtml

Phenomenal.

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:05am

So, at 8:45pm last night, the Tweed tide gauge recorded a 0.47m positive residual, and then a 0.23 negative residual at 9:15pm (i.e 0.7m drop over half an hour). That's quite impressive.

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:05am

Wow, most impressive location the East Coast seems to be Crowdy Head, where the marina saw a negative residual of -0.61m at 9pm, and then a positive residual of 0.69m at 10pm (with a few waves between). That's a 1.3m tidal range over sixty minutes.

Supafreak's picture
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Supafreak Sunday, 16 Jan 2022 at 7:14am

Reading through the Twitter comments last night, amazing how far away this could be heard , must’ve been terrifying on tonga hearing the explosions.

batfink's picture
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batfink Sunday, 16 Jan 2022 at 7:19am

Is that 9 pm and 10 pm last night Ben? (not 10 am)

Looks like 4 waves, so period of 15 minutes? ;-)

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:24am

Ah yep, corrected.

Would need the raw data to calculate period.. I'll see what I can find.

Roadkill's picture
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Roadkill Sunday, 16 Jan 2022 at 7:20am

Pretty amazing stuff.

seaslug's picture
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seaslug Sunday, 16 Jan 2022 at 9:44am

wow some amazing footage there RK

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:30am

Here's the Crowdy Head marina data in more detail. Each data point is 15 mins apart.

How's the drop in water level in the fifteen minutes between 10:00pm and 10:15pm: residuals went from +0.69m to -0.47m (actual water level went from 1.38m to 0.17m, second image).

That's a 1.2m drop in water in fifteen minutes. Like pulling the plug out of the bathtub! That'd drag boats out to sea (if they weren't moored properly inside the marina).


Solitude's picture
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Solitude Sunday, 16 Jan 2022 at 7:31am

When there’s already a couple of metres of swell out there, is there anyway of discerning with the eye on the ground what is or isn’t a tidal wave?

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:42am

First up, it's not a tidal wave (it's a tsunami). And it's more of a surge, than a wave. Like a larger version of the infragravity waves we've been discussing here for the last few years.

So the perception is all dependent on size - this current event in Australia is relatively small (compared to what the public's perception may be of tsunamis, i.e. Japan, Indo etc) - so you're right - it would be a little hard to discern. Though experienced surfers would notice a significant increase in the volume of water moving through the surf zone, unusual currents, temporarily exposed rocks that are normally underwater etc.

Inexperienced surfers (or non surfers) probably wouldn't notice much, apart from the infragravity sweep up the beach (by which time it's too late).

Either way, this is a very uncommon event that we don't have a lot of upstream tools to monitor and assess - so I'd highly recommend being overly cautious for the next day or so. Better still, completely avoid low-lying coastal areas.

Solitude's picture
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Solitude Sunday, 16 Jan 2022 at 7:51am

Yeah makes sense, I was thinking about those previous articles on infra gravity waves.
So what is a singular wave from a tsunami known as then? A tsunami wave?

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 8:09am

Not sure, actually - tsunami is both singular and plural. A soliton is a solitary wave, but different to a tsunami... and now we're well and truly outside of my area of expertise!

Some light Sunday reading for y'all: "On the solitary wave paradigm for tsunamis".
https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2008JC004932

batfink's picture
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batfink Sunday, 16 Jan 2022 at 7:54am

May have heard it here last night but we had a minor thunderstorm come through in the evening and would have just written it off as more thunder. One particular crack seemed quite unusual. Don’t know.

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 7:59am

T'was a series of quiet, small rumbles here on the Tweed Coast, which would have been undetectable if there'd been any ambient noise (it was very still at the time). Wouldn't have been a thunderstorm-like 'crack', I reckon (not this far away from Tonga).

batfink's picture
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batfink Sunday, 16 Jan 2022 at 10:08am

Makes sense. Would have just been distant rumbling from a thunderstorm, I understand it was heavy nearby but we just caught the edge of it.

sean killen's picture
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sean killen Sunday, 16 Jan 2022 at 8:23am

Too risky going for a wave? .. got two mates gone out crack of dawn .. probably oblivious to the warnings..

blindboy's picture
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blindboy Sunday, 16 Jan 2022 at 8:28am

From first hand experience, if you are in the water when it happens the first thing you are likely to obseve is a sudden drop in tide. The size of that should give you a rough idea of what will follow.

Craig's picture
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Craig Sunday, 16 Jan 2022 at 8:44am

No risk as the height is minimal for NSW and out in the surf zone you'd hardly notice it. All the action was last night as well unless there's been further eruptions?

Quick calculation for timing as well is the shallow water wave equation. Speed = sqrt(depth*gravity). So say an average of 3,000m and gravity = 9.8 so speed is 171.46m/s = 616km/h.

Sydney is some 3,600km away so 6 hour travel time which equals 9pm last night.

sean killen's picture
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sean killen Sunday, 16 Jan 2022 at 8:47am

When this girl (Mother Nature) are this angry and unpredictable best left alone for a while ..

sean killen's picture
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sean killen Sunday, 16 Jan 2022 at 8:49am

Cheers Craig

phnud's picture
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phnud Sunday, 16 Jan 2022 at 8:52am

Don’t suppose this will lead to a correction in coastal real-estate prices?

palpacino's picture
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palpacino Sunday, 16 Jan 2022 at 9:54am

Hey Ben/Craig,
How will this event mix with the jump in period from the east on the east coast this afternoon?
My wife is saying I shouldn’t go surfing.
Thoughts?

thermalben's picture
thermalben's picture
thermalben Sunday, 16 Jan 2022 at 11:28am

Definitely heed caution if you are heading down. If you're risk averse prob worth staying out.

seeds's picture
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seeds Sunday, 16 Jan 2022 at 1:04pm

That was unnecessary

Island Bay's picture
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Island Bay Sunday, 16 Jan 2022 at 9:58am

Shockwave shook our house here in Raglan.

Colleague's pressure gauge in Wellington registered a sharp 5hPa spike.

fitzroy-21's picture
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fitzroy-21 Sunday, 16 Jan 2022 at 11:04am

Pre-cursor to the big one yesterday?

blackers's picture
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blackers Sunday, 16 Jan 2022 at 12:37pm

Far out, astounding.

seeds's picture
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seeds Sunday, 16 Jan 2022 at 1:07pm

Was it an under water volcano as reported? Seems to be land above sea in footage or is that nearby to the eruption site? Impressive sonic cracks shot/ heard from Fiji in that footage

fitzroy-21's picture
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fitzroy-21 Sunday, 16 Jan 2022 at 1:58pm

&t=232s

seeds's picture
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seeds Sunday, 16 Jan 2022 at 3:15pm

The caldera is underwater and the above water mass is the spoil?
As in it’s not classified as an island yet?
Edit. It’s between two small islands by the looks from that Fitz and creating one big one. But in reality has been in existence since 2015. The other two small islands from spoil from the past? What we can see in vids?

Cockee's picture
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Cockee Sunday, 16 Jan 2022 at 3:13pm

'According to the BOM, large waves have been observed on Australia's east coast, with Queensland's Gold Coast seeing waves of up to 0.82 metres and Twofold Bay in southern NSW recording 0.77 metre waves.' That's frightening stuff alright.

thermalben's picture
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thermalben Sunday, 16 Jan 2022 at 3:29pm

batfink's picture
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batfink Sunday, 16 Jan 2022 at 4:13pm

So yes, the shock wave literally went around the world. If you click on Ben’s Twitter pic it takes you to a page which discusses it and scroll down till you find a globe with comments confirming, with pictures.

The antipodes of Tonga is over North Africa. That’s one I’ll take to my grave, or forget by tonight. Not sure which.

hoody's picture
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hoody Sunday, 16 Jan 2022 at 4:38pm

When the Indo Quake happened I was working in Coffin bay. We were in Tit deep water doing oysters. The water started dropping but only slowly till it was knee deep, probably twenty minutes. The tide was meant to be still coming in. Then it slowly filled back in to where it was before. A couple of weeks later I saw the animation of the wave and it lined up perfectly for the time that it happened. Pretty Cool

billie's picture
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billie Monday, 17 Jan 2022 at 6:05pm

So cool!

Queef Jerky's picture
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Queef Jerky Sunday, 16 Jan 2022 at 8:47pm

Ben has a boner!

keano's picture
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keano Sunday, 16 Jan 2022 at 10:17pm

Update from Pita Taufatofua from the gofundme page I posted a link to earlier.

'Thank you to all of you for sharing and donating. We understand that times are tough yet you have still managed to help out, it is truly appreciated! It's late and we have high hopes that tomorrow morning the ash would have settled enough in Tonga for the New Zealand defense force to fly across and make an assessment. Communication to Tonga is still cut off and the assumption is that the undersea cable that allows internet and phone communication is damaged.
Many Tongans around the world are in the same boat as me and worried about their families in Tonga. Praying that more information comes through tomorrow. Once again we thank you for your assistance. As communication opens up we will get a better assement of the damage and needs of the people.
Ofa Atu
Pita'

Distracted's picture
Distracted's picture
Distracted Monday, 17 Jan 2022 at 8:17am

Keano, thanks for posting, been wondering about what is happening in Tonga. Apart from the initial Twitter videos it has gone really quiet. Could be a lot of damage and lives lost.

Matilda0213's picture
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Matilda0213 Monday, 17 Jan 2022 at 7:27am

Hey Ben could the tsunami have changed the current direction? Paddled out at a tweed beachie sunday morning and the current had reversed from saturday. Looking at the tweed buoy data seems to be a big spike to the north then corrects or maybe it was from the north winds?

thermalben's picture
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thermalben Monday, 17 Jan 2022 at 7:54am

Absolutely. Massive effect on inshore currents.

The Tweed buoy is located further offshore though, so I'm not sure how the tsunami might have affected the EAC (certainly possible though).

Assessing the data though - the image below shows current speed (blue line) and direction (red dots) and the yellow arrow marks the time the tsunami started impacting the region. Max current speeds in the early hours of Sunday morning was a little over 1kt (not much).

And whilst current speeds did increase following the tsunami, the direction looks pretty steady S/SE. Current direction is usually measured the opposite of winds - that is, S/SE is the direction the current is flowing TOWARDS (so, it's flowing from the N/NW to the S/SE).

Note: the scattered direction data from the previous 24 period is related to a very slow current speed, kinda like 'light and variable winds' will blow from any direction.

My experience in the water on the Tweed y'day was powerful inshore northerly currents at one spot (moving from south to north), and a slight southerly current at another spot. All within the space of a few hours. So, quite variable.

Matilda0213's picture
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Matilda0213 Monday, 17 Jan 2022 at 8:44am

Thanks Ben great info!

thermalben's picture
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thermalben Monday, 17 Jan 2022 at 9:39am

As per Don's comment in the Qld Forecaster Notes, the offshore buoy at Tweed did show an increase in current speed from about the time the tsunami arrived. But, the EAC has been known to reach speeds up to 5kts, so the data's not extraordinary.

Still, quite likely a cause/effect from the tsunami.

Island Bay's picture
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Island Bay Monday, 17 Jan 2022 at 9:28am

Pressure wave travelled around the world a few times. Here's the track from my colleague's pressure gauge in Wellington, NZ.

thermalben's picture
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thermalben Monday, 17 Jan 2022 at 9:40am

Amazing!

Island Bay's picture
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Island Bay Monday, 17 Jan 2022 at 9:50am

Science can be fun, aye - though less so if you're in Tonga :-(

thermalben's picture
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thermalben Monday, 17 Jan 2022 at 9:55am

Indeed.

Gotta say too, up until yesterday I always found it a little hard to comprehend how the explosions from Krakatoa were heard around the world. Science tells us so, but I just couldn't imagine it.

Now I've got first hand experience!

Island Bay's picture
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Island Bay Monday, 17 Jan 2022 at 10:43am

Me too. I had all the Time Life books growing up, and I looked at images of Krakatoa and Anak Krakatoa, and read the stories completely enthralled.

Here's some more incredible stuff:

Craig's picture
Craig's picture
Craig Monday, 17 Jan 2022 at 10:53am

Wow sick!

Craig's picture
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Craig Monday, 17 Jan 2022 at 11:32am

A great video (2nd post) of the spreading tsunami..

Craig's picture
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Craig Monday, 17 Jan 2022 at 11:44am

Also an account from Andrew Bagnell who was in Fiji surfing..

"We pulled up in the boat, surf was firing and we jumped in. A set rolled through and I paddled for it but pulled back as something seemed a bit odd, and suddenly we were all in what felt like a river surging along the edge of the reef pulling us down the line about 300m or so.

The boat saw and came to get us. We hopped in and then the current turned and went the other direction.
Took us a few minutes to work out what might have happened as we had heard the eruption an hour earlier but had no idea what it was at the time.

Then we got back to the resort and they'd seen the news about the volcano so we figured it must have been a small tsunami."

Clam's picture
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Clam Monday, 17 Jan 2022 at 1:33pm

swellnet has the best info to be found about this event

Sprout's picture
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Sprout Monday, 17 Jan 2022 at 4:04pm


Spuddups's picture
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Spuddups Tuesday, 18 Jan 2022 at 6:53am

Fark, it's been obliterated.

GreenJam's picture
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GreenJam Monday, 17 Jan 2022 at 4:44pm

strangely, my tv literally exploded on Saturday evening, no shrapnel or anything, just a very loud 'pop/bang' and the smell of burning electrics. Dead. Looking at the image shown above re the MSLP, it coincided pretty much right at the time of that big drop in pressure on the Brisbane line.
any chance this could be related? or just a crazy coincidence.
the tv wasnt very old

Distracted's picture
Distracted's picture
Distracted Monday, 17 Jan 2022 at 6:40pm

@Ben, wonder if that ‘blistering sunrise’ on Sunday morning on the Yamba cam screen shot might have been due to the ash cloud?

thermalben's picture
thermalben's picture
thermalben Tuesday, 18 Jan 2022 at 11:00am

Surely it must have! Here it is:

Off sure's picture
Off sure's picture
Off sure Tuesday, 18 Jan 2022 at 9:56am

Nice time lapse video of the tsunami at Mogareeka inlet: https://theconversation.com/waves-from-the-tonga-tsunami-are-still-being...

donweather's picture
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donweather Tuesday, 18 Jan 2022 at 3:31pm
Craig's picture
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Craig Tuesday, 18 Jan 2022 at 3:39pm

Would say that's more due to the slackening of those east to north-east winds and the suppression of upwelling, with the EAC filling back in.

john.callahan's picture
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john.callahan Tuesday, 18 Jan 2022 at 6:45pm

This Tonga volcanic eruption event is probably the closest approximation to Krakatoa since, well Krakatoa in 1883.

Incredible natural forces at work -

Distracted's picture
Distracted's picture
Distracted Tuesday, 18 Jan 2022 at 9:16pm

Offsure, that’s a pretty cool seeing little video. Wonder what it would have looked like when the main wave hit.

Here’s a different sequence showing the growth then utter atomisation of the volcano.
https://mobile.twitter.com/spahn711/status/1483197121063002115

Craig's picture
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Craig Friday, 21 Jan 2022 at 11:14am
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Craig Thursday, 31 Mar 2022 at 8:26am

Magnitude 7.0 recorded off New Caledonia. 33km deep.

https://earthquakes.ga.gov.au/

No threat to Australia.