Large Eruption Near Tonga, Heard in NZ. Tsunami at Tonga and Fiji

871 points4
perihelions4 days ago

The satellite imagery is incredible -- you can see atmospheric waves traveling hundreds of kilometers: (GOES-West) (Himawari-8)

Edited comment: originally linked to the wrong satellite imagery (from a separate eruption several hours ago). The discussion in this link is still informative, but not current:

Cyykratahk4 days ago

Here's the Himawari-8 satellite viewer, centred on the eruption.

Press the right arrow icon in the bottom right to advance to the next 10min snapshot.

You can also download high-res images (11000x11000 PNG): (you might have to click this link twice for the search to work)

samb17294 days ago

For anyone wanting to see the same shockwave as is linked here in video form, a BBC article[0] has a it embedded. The Himawari viewer works well for stills but makes the effect over time a bit harder to appreciate.


curiousgal3 days ago

Seriously fuck the BBC and their Cookie Consent prompt, do they really expect me to manually untick every single vendor?

ceejayoz3 days ago

No, they expect you to give up and accept them.

The worst one I ever saw was where above the fold items were unchecked, but the below the fold items were checked where you couldn’t see them.

robin_reala3 days ago
thorsten113 days ago
IanCal3 days ago

I'm curious as to what you see (I'm in the UK so there are very strict legal requirements that the BBC don't show ads so my page will be different to yours) for me the cookie prompt is at the top and pushes the content down a little but I can ignore it and see everything. That meets gdpr requirements as I can still do what I want and unless I tick OK nothing should be set.

zh33 days ago

That sounds like a different experience to what we get in the UK - one cookie prompt and you're good to go for many months (at least).

Could be the BBC's fault, possibly due to in-country legalese though?

madacol3 days ago

Use incognito, or Firefox + Multi-account Container + Temporary containers

johnmaguire3 days ago

uBlock Origin + EasyList Cookies or Fanboy Annoyances.

blobbers3 days ago

This is FANTASTIC! Thank you so much for sharing these links. Kids loved this, as we had just learned about similar volcanic eruptions through a recent Nat Geo magazine.

dylan6044 days ago

I think this might be the first satellite imagery I've seen that caught the color change in the clouds at sunset..

irrational3 days ago

So it looks like the eruption happened right at dusk. For some reason that feels to me like that would make it worse for the people.

zh33 days ago

Yeah - the timelapse of the terminator showing darkness descending suggests it's was a rough night.

gokhan4 days ago

Himawari-8 footage is excellent. That shockwave is gigantic. Thanks for the link.

neom4 days ago

Really makes you think about how cool satellites have gotten. After some googling, I learned Himawari is a Japanese weather satellite:

awb4 days ago
johnyzee4 days ago

That's the best one. Incredible. To imagine that Tonga is practically right at ground zero. Anyone know how this measures in megatonnes?

quakeguy3 days ago

100-160 Mt i saw rumored on Twitter.

AtlasBarfed3 days ago

Is my wikipedia-ing correct? Krakatoa was 200 Mt?

beamatronic3 days ago

Are the Tongans okay?

awb3 days ago
qwertox4 days ago

Thank you for your incredible link collection.

Here is an animated gif in the relevant timeframe, 9 MB in size.

and one hour earlier

matkoniecz3 days ago

404ing for the first link

qwertox3 days ago

Oh no! Both links are a 404 now. Why didn't I save them :(

perihelions4 days ago

Here's alternate versions with 24-hour long windows (not ideal), because I haven't figured out how to link timestamps in the URL parameters of satellite loops, so they are shifting forwards in time. (I'm sure someone else will figure out a better solution: I've given up). (GOES-West) (Himawari-8)

Taniwha4 days ago

There was one yesterday and a bigger one 3-4 hours ago

awb3 days ago

And potentially more eruptions after the big one:

wyclif4 days ago

They are evacuating Lord Howe Island.

carbocation4 days ago

FYI there is a tsunami advisory for the entire west coast at this point: (specifically at [1], but will contain the latest).

Expected arrival times in California (Pacific Time):

     * California
    Fort Bragg       0735  PST Jan 15
    Monterey         0735  PST Jan 15
    Port San Luis    0740  PST Jan 15
    Santa Barbara    0745  PST Jan 15
    La Jolla         0750  PST Jan 15
    Los Angeles Harb 0750  PST Jan 15
    Newport Beach    0755  PST Jan 15
    Oceanside        0755  PST Jan 15
    Crescent City    0800  PST Jan 15
    San Francisco    0810  PST Jan 15
1 =
not2b3 days ago

The parking lot at Santa Cruz (California) Harbor flooded and there was some minor damage, though a lot less than from the 2011 tsunami from the Japanese earthquake. It was only about a 30 to 50 cm surge (one to 1.5 feet) but happened at high tide.

matkoniecz3 days ago

Any info how large it is expected to be?

The advisory is really unclear how it is on scale "measurable wave" to "run away immediately"

Lack of specific seems to point to the first one but...

Rebelgecko3 days ago

A few feet. It looks like there was some light flooding at a marina in Santa Cruz:

whoisburbansky3 days ago

You can see wave heights by looking at the residuals plots on tide stations: Looks like 2ft peaks in Monterey?

awb3 days ago

Not too big on the West Coast, it hit Santa Cruz and caused minor flooding at the harbor.

awb3 days ago
sonium3 days ago

> If you are in a tsunami advisory area;

>* A tsunami with strong waves and currents is possible.

matkoniecz3 days ago

"Strong waves" may be anything from "measurably stronger wave" to "0.5m tsunami wave that requires evacuation from flat coastal areas"

tomc19853 days ago

Huh, Fort Bragg is a lot closer to Crescent City than Oceanside. I would think the earliest time would be the center of the incoming wave?

cjnicholls4 days ago
irthomasthomas4 days ago

Did they know this was coming? Or how did they manage to have the satellite centred over the volcano at the right moment?

Edit: Found the answer, this was the second or third eruption from this volcano. So yeah they where already monitoring it. Amazing how they can manoeuvre these camera satellites now.

perihelions4 days ago

It's a weather satellite 36,000 km from Earth; half of the planet is contained in its field of view. Here, see:

irthomasthomas4 days ago
JshWright4 days ago

The satellite wasn't maneuvered, and it was not specifically monitoring this location. It is a weather satellite that looks at half the planet at a time. This is just a crop of a much wider field of view.

pavelrub4 days ago

Satellites in general aren’t maneuverable. The camera angle can be changed to point at, and capture, a region of interest when the satellite passes over it, but the satellite’s orbit is determined on insertion and doesn’t change on demand.

Symbiote4 days ago
temp08264 days ago

Exception of course being the X-37B spy "satellite"

perihelions4 days ago

Barometer data here:

Roughly +/- 300 Pa pressure wave in New Zealand, about 2,000 km away.

rz2k3 days ago

This is from two indoor BMP280 sensors on Home Assistant that are about 5300 miles from Tonga. (They are a floor apart from each other)

It's amazing what extremely cheap sensors can currently measure, though 1883 technology was sufficient to measure the pressure wave from Krakatoa circling the globe multiple times.

r7214 days ago
Taniwha4 days ago

It's worth noting that that cloud is (very) roughly 150km across

dylan6044 days ago

I wonder at what point the person shooting that footage starts to question their decision of not getting to higher ground than single story roof

GekkePrutser4 days ago

Whoa that second link.. that guy is so lucky this didn't turn into a full blown tsunami.

I don't think I'd like to live right at the coast if I were in the Pacific.

But luckily it seems to be more of a slow eruption

runeks4 days ago

> Whoa that second link.. that guy is so lucky this didn't turn into a full blown tsunami.

That is what a full blown tsunami looks like, based on watching many YouTube videos on the subject.

Bear in mind this is only a minute of footage. If the water keeps coming in like that for an hour it will eventually reach the person shooting this video.

The scary thing about tsunamis is that they look fairly innocent in the beginning. And five minutes later there’s ten feet of water moving very fast with houses and cars in it.

Here’s a good example of how it can go from looking harmless to terrifying in 25 minutes:

jsrcout3 days ago

That's a sobering video. It doesn't look like much... at first. The power and violence of the water really has to be seen to be appreciated.

Edited to add:

On March 11, 2011, large parts of the city were destroyed by the tsunami which followed the Tōhoku earthquake. The island of Ōshima and its 3,000 residents, included in the city limits, was isolated by the tsunami which damaged the ferry connections.[7] After the tsunami, spilled fuel from the town's fishing fleet caught fire and burned for four days.[8] As of 22 April 2011, the city had confirmed 837 deaths with 1,196 missing.[9]

johnyzee4 days ago

Wow. Watching the people's attitude change, from puttering around in slippers joking about the first quaint little trickle, to full judgement day, within twenty minutes.

mythrwy3 days ago

Wow! Someone else already mentioned it, but this so "interestingly unusual" to "apocalyptic" in twenty minutes it's hard to fathom. Thanks for sharing the link I personally had no idea!

mannykannot3 days ago

The term 'tidal wave' has been deprecated for some time, as they are not gravity-driven, but it does capture how the wave does not just break on the shoreline like an ocean roller, it keeps on coming.

Taniwha4 days ago

This is a real tsunami, just not really really big, they are partially protected by a reef. It's not a slow eruption (check out the shockwave in one of the videos, heard in New Zealand). There was a smaller bang yesterday.

kzrdude4 days ago

Some of these communities have nothing but a coast!

It's probably in a Jared Diamond book somewhere about shifting expectations depending on where you grow up, some people can't imagine that people live in a place where you can't hear the sea, because they only knew that.

Someone4 days ago

Also, for those that have some high areas, chances are the high areas are a volcano. If it is, it likely is an active volcano, as this region is on the ring of fire (

divbzero4 days ago

What would be the timescale of those satellite videos? I imagine they must be time lapse videos?

perihelions4 days ago

It has a 10-minute repeat rate (one frame); you can see the timestamps here,

sml1564 days ago

Judging by the movement of the sun I would guess a couple of hours, It's hard for me to tell with all the clouds in the sky.

>What would be the timescale of those satellite videos?

They are animated gif's just a bunch of frames from the original video.

mtoohig4 days ago

Here in Vanuatu we could also hear it. On facebook people from all the islands are talking about it and were trying to figure out if it was one of our own island volcanoes that erupted.

watersb4 days ago

Has Vanuatu been affected by tsunami or ash ejecta?

I have a friend there. I hope you all stay safe. And then I wonder about air travel impact for all of the region.

mtoohig1 day ago

Tsunami was minor but no ash here yet. Everyone is okay :)

Nitrolo4 days ago

Does anyone with knowledge about volcanoes have context on how big this is? Clearly not small, but is this a once-in-a-decade or a once-in-a-lifetime size explosion? Are there any well-known eruptions to compare it to (e.g. Mount St. Helens)?

miedpo4 days ago

Not a volcanologist here but I've always loved volcanoes.

It's probably gonna depend on how long it keeps erupting. Volcanic eruptions are rated (VEI index) on volume of material ejected, but each level has 10x more material than the previous.

If this were a volcano on land... I'd guess we are at a 4 or so. As this is a volcano that just barely breached the surface and thus interacts with water alot... maybe a 3? Volcanoes like this create really violent explosions (like the ones heard yesterday), but that doesn't necessarily require more material.

As said though, it'll be hard to tell without knowing how long the eruption went on and seeing the state of the island.

Robotbeat4 days ago

Probably between VEI 4 and 6 inclusive.

hliyan4 days ago

It is believed that the mystery eruption of 1808 originated in the same area.

scottatron3 days ago

According to this one is pretty much right on schedule for an eruption of this size every ~1000 years.

vba6163 days ago

I initially misinterpreted this.

After checking the link, it seems it is saying this event is a 1 in 1000 year event for this volcano, not for the world in general.

I guess it could be both, but they don't appear to be saying that.

hugh-avherald4 days ago

It's unknown precisely (still erupting), but it's probably not even the largest eruption in the last few months.

totaldude874 days ago

Not sure someone else shared this , but this looks scary

phreeza3 days ago

My watch was able to pick up the pressure wave in Switzerland, on the other side of the earth. It's the little spike around 25% from the left. I wouldn't have believed it but the magnitude, timing and shape line up with what others have reported from stationary barometers on twitter.

noduerme4 days ago

Man. This has got to count as the largest explosion on earth within any of our lifetimes. Anyone got a figure on how much pulverized rock would have been displaced into the atmosphere had this taken place on dry land? How long a nuclear winter we'd be in for? Or how this compares to Krakatoa? From the imagery it seems orders of magnitude larger as a single explosion than all the nuclear weapons we ever detonated combined. That shock wave goes over Tonga within the first couple frames.

Robotbeat4 days ago

It still remains to be seen exactly how big it is. My feel is it’s slightly smaller than Mount Pinatubo in 1991 (in my lifetime) which significantly reduced global temperatures for a bit. Folks have suggested maybe 0.1 to 0.5C (0.2 to 1 degree F) temporary temperature reduction.

Probably 4-6 on the VEI scale.

bb1234 days ago

I wonder if the debris this puts up into the atmosphere will help slow the effects of climate change

cyanydeez4 days ago

its theorized massive amounts or co2 wouod be released from yellowstone.

more realistically, this would just cool for a few years, make climate denial easier to believe, then signficantlymrebound in amcoupke of years

esahione4 days ago
colordrops4 days ago
miedpo4 days ago

Probably not. Way to small for that, and even the early large eruptions only affect the atmosphere noticably for a year or two (unless it's a really really really crazy large eruption that makes Tambora look like tiny)

Fordec3 days ago

They won't slow it, but pause effects for a short while. The CO2 would still be there afterwards and all the while increasing, the oceans will still be acidifying, etc.

The next years after would still be as bad as predicted

colechristensen3 days ago

Possibly, but only briefly, highly dependent on the composition. Previous large explosions had measurable cooling effects for a year or two.

noduerme4 days ago

It would... if it weren't underwater.

jcims4 days ago

The cloud you see in the satellite image is in the atmosphere.

Tepix4 days ago

Since the dec 20 2021 eruption it's been an island.

dylan6043 days ago
noduerme4 days ago
bb1234 days ago

Ah I didn’t realise that. Thanks for clarifying.

Valmar4 days ago

That's a pretty awful hot take.

Unless this is some terribly poor trolling, in which case I've taken your bait...

tasha06634 days ago
bb1234 days ago

Not sure what a hot take is. It was a a genuine question - volcanic eruptions have well documented climatic effects.

noduerme4 days ago
noduerme4 days ago

Eh, that's what I was thinking too (except it's underwater). One good belch like this from Yellowstone and we'd be back in an ice age.

maxerickson4 days ago
2OEH8eoCRo04 days ago

What length of time are these satellite videos taken? I think it might make the explosion look larger than it really is. What we are seeing is the billowing flat top of the debris cloud.

s1artibartfast3 days ago

Unlikely to be that big. More like a once per year to once per decade eruption.

If this is indeed a VEI4, Krakatoa would have been 100x bigger.

99_003 days ago

And fertilizer prices are already extremely high due to Nat gas shortages. Crop yeilds are going to be bad.

fguerraz4 days ago

I actually quite like the "zoomed-out" version, it really shows the scale of the event. Look at the bottom right quadrant of this video:

Big thanks to earth2day again!

ByThyGrace4 days ago

The expansion of the shockwave there is almost like running a race against the terminator, but not quite as fast. Amazing.

tgbugs3 days ago

It looks like there was another eruption in a volcano north east of there the day before?

dredmorbius4 days ago

Wikipedia's article on the topic should be a good onging / updated summary of the event:

bandyaboot3 days ago

I saw a thread on Twitter regarding the expected pressure spike that should be happening shortly in Southern Algeria as the pressure waves converge from opposite directions at the antipode of the volcano. Thought that was pretty interesting.

awb3 days ago

Really interesting! Maybe this is the thread?

Author says no danger to Algerians BTW.

bandyaboot3 days ago

Yeah, that’s the one.

MontagFTB4 days ago

US Stormwatch has an incredible shot of the eruption- the largest ever captured by satellite:

georgeburdell4 days ago

Is there any website tracking how long the sound would take to reach various locations? I’m guessing I might be able to hear a gentle rumble in SF

Edit: some Googling tells me it's about 5300 miles from SF to this volcano. At 767mph, that's 6 hours and 54 minutes. The volcano erupted at 8:26pm Pacific, meaning at around 3:20am Pacific time the sound should reach SF.

quickthrower24 days ago

Heard nothing in Sydney Australia .. so I wouldn't count on hearing it from SF.

mcyukon3 days ago

I live in the Yukon Territory, Canada... Not 100% sure this explosion is what woke me this morning but:

I woke up at 7:15 AM MST to what I though was a freight truck loading boxes at the business next door. Rumbling, thudding noises. Very faint. Promptly ignored it and tried to go back to sleep, a few moments later my sister 100 KM outside of my location on a off-grind property texted me asking if I could hear thunder/fireworks like noises outside. Noise probably lasted 10-15 minutes.

I did some napkin math for speed of sound and it gets close.


9,700 KM distance Tonga - Whitehorse, YT

1,225 Km/hr speed of sound @ 20C

~7.9 Hrs to get here

3:10 PM AEDT Saturday 1st Explosion - 9:10 PM MST Friday + 8 Hrs = 5:10 MST Saturday

5:26 PM AEDT Saturday 2nd Explosion - 11:26 PM MST Friday + 8 Hrs = 7:26 AM MST Saturday

HeyLaughingBoy3 days ago

Accounting for inaccuracy, temperature changes along the way, wave diffraction, etc., I'd say you heard it.

jb19913 days ago

It was heard easily in North America:

> The eruption of the Hunga Tonga-Hunga Haʻapai volcano was heard across the South Pacific, and eventually as far away as the US.

pleb_nz3 days ago

It was heard in NZ, some as south as Christchurch claiming to have heard it. In in Christchurch and didn't hear it but did see changes in air pressure was the sound waves went through.

fguerraz3 days ago

You know it's bad when the tide gauge data stops suddenly. :/

AnotherGoodName3 days ago

>“We continue to try and contact the Tonga network operations centre but at this stage remain unable to do so, even via satellite phone. While we understand Tonga also has satellite links, we don’t know whether the satellite ground equipment has been affected.”

The ground link between Fiji and Tonga was broken. Even satellite links are down due the ash cloud. That's why there's no telemetry from anything at all. Hard to imagine but we have no link to Tonga.

yosito3 days ago

What about radios? Any radio connections?

zimpenfish3 days ago

Shockwave as seen from York, UK (both directions).

Thread collecting other amateur observations.

Seems my indoor Netatmo module also caught it -

8bitsrule3 days ago

Recording of a (very loud) blast hitting Tonga, it says

Taumoefolau: tsunami landing video

quantumfissure4 days ago

Really, unbelievably cool satellite images. I don't know much about satellite imagery, is Himawari-8 always pointed to that area in the Pacific, or did we expect it to explode and was purposefully pointed towards the island?

Here's what I honestly worry about: queue the conspiracies, "New islands don't just explode like that! That's the Fauci-Gates COVID-5G nuclear testing site sheeple!"

...cause Krakatoa definitely never happened.

twic4 days ago

It's in a geostationary orbit at 140.7 degrees east, roughly in line with the east coast of Japan, and about 35 degrees west of the volcano, so it always has the volcano in view. It has an imaging sensor which continuously scans the whole visible disc of the earth, taking ten minutes to do so [1]. So, you get pictures of anything that happens, anywhere!


_Microft4 days ago

Yes, Himawari-8 is a geostationary satellite over longitude 140deg east and always pointed there. The Wikipedia article contains images of the full disk of Earth that it is observing. Since it is geostationary, the view does not change.

vdo3 days ago

Along southern Alaska, the shockwaves were audible a few hours ago. I slept through it, but my feed has people complaining of having been woken up. Our local subreddits have posts from people being confused about potential thunder or military exercises. It is incredible to think of the energy involved in these events.

darknavi3 days ago

Do you know what time? I'd love to see if any of my cameras picked it up but hard to scrub audio in large quantities.

vdo3 days ago

Around 4-5 AM AKST going off what I see others have been saying, sorry I don't know precise timestamps. One of the posts in /r/alaska was at 4:50 AM. One in /r/anchorage was at 4:39 AM.

Edit: Alaska Volcano Observatory just posted this graph of the pressure wave here

tazjin3 days ago

Put the audio in a tool that visualises it (e.g. Audacity), should make the segments easier to pick out than scrubbing.

jwtorres4 days ago

Getting crazy tides sloshing in and out of the marina every couple minutes here on Oahu.

accidue4 days ago

Amazing satellite crop here:

Top middle - eruption Left middle - cyclone Cody Bottom left - New Zealand 2000km/1200miles away

twillin4 days ago

I live on a boat in Southern CA. Can someone here help me quantify how concerned I should be about this?

sabareesh4 days ago

please see the notes below

Get into deeper water

MrsPeaches4 days ago

Selected section for boat operators:

* Boat operators, * Where time and conditions permit, move your boat out to sea to a depth of at least 180 feet.

     * If at sea avoid entering shallow water, harbors,
       marinas, bays, and inlets to avoid floating and
       submerged debris and strong currents.

 * Do not go to the shore to observe the tsunami.

 * Do not return to the coast until local emergency officials
   indicate it is safe to do so.
This doesn’t seem to be specifically about house boats. Might be worth contacting your local emergency officials (whoever they may be).
db48x3 days ago

To be honest, this is the kind of thing you should look up before you decide to live on a house boat.

mdoms3 days ago

You probably know more about living on a boat than most people here, you tell us.

ggm4 days ago
Taniwha4 days ago

Actual tsunamis have been reported in Fiji, and of course Tongatapu

sriram_sun4 days ago


"Tsunami Advisory Alert color: Orange

When a Tsunami Advisory is posted, tsunami conditions in or near the water are expected. Under an advisory, strong ocean currents and/or waves with the potential to cause coastal damage are expected.

The public should stay out of the water and away from beaches and coastlines."

r7214 days ago

>Incredible footage has emerged of the Hunga-Tonga-Hunga-Ha’apai volcano erupting sending ash, steam and gas 20 kilometres into the air.

gchokov4 days ago

This short video from Independent is incredible as well -

Edit: Shame, it's from the day before. Still interesting, so leaving it here.

pkdpic4 days ago

> A tsunami advisory is in effect Saturday morning for the West Coast, including coastal California and parts of the San Francisco Bay Area, after a large underwater volcanic eruption near the Tonga Islands Friday night.

The National Weather Service said peak waves of one to two feet are possible from the event.

[from sfgate]

Just in case anyone with family in sf was wondering.

ryzvonusef3 days ago

the google maps location, incase anyone was curious:

tootahe453 days ago

I could hear these large thuds all the way from the top of the south island, NZ, in the hills and at around the same time others were reporting it. Definitely heard like 20+ of these sounds, just assumed it was some anti-pest thing going off at random intervals but it was pine forest so doubt it was that.

peter3034 days ago

Normally Tsunami algorithms start calculating/warning when there is M7 or higher. As an "airquake" the registered magnitude is negligible.

tunnuz3 days ago

Crap, I hope people are safe :(

dontbeabill3 days ago
bioinformatics3 days ago
motorist_hacker3 days ago
maximp3 days ago

Can't report but someone who can should - video is unrelated to thread.

motorist_hacker3 days ago
bigyellow4 days ago
dylan6044 days ago

Yes, you are right, nobody except you has ever thought about the events of volcanism on the climate.

Where in the world do you think that this has never been discussed? What goes on in your thought processes that suggests this?

Kelamir3 days ago

I think you have a point there, but it could sound less condescending. It is really putting off. I personally don't think it leads to anything constrictive, only makes people feel worse about themselves.

dylan6043 days ago

Maybe, but to be honest, that was the re-edited dialed back version. The original post I replied was way to trollish/consipiracy pushing. "question no one else will ask" is just obvious attempt at a dog whistle, but instead grabbed the football ref whistle.

jcranmer3 days ago

Volcanic eruptions have climatic effects on short timescales--think a few years of maybe ~0.5°C cooling (this is going by Pinatubo's eruption ~30 years ago).

schainks4 days ago

It looks like measurements are still ongoing, be patient.

bigyellow3 days ago

My comment was already "flagged" and hidden from public view, questioning "climate change" is too controversial for "hackers" ... oh, my sides.

transitory_pce4 days ago

Does Larry still live there?

dzhiurgis4 days ago

These volcanos have been on since December so I guess he'd bailed since then.

The_rationalist4 days ago

Are there similar satellite imagery for the probably much bigger explosion that was krakatoa?? If no why..

wolfram744 days ago

The big krakatoa eruption wiki lists was 1883[0], while tsiolkovsky was doing some theory by then, nobody was building satellites.


thehappypm2 days ago

Is this parody?

janmo4 days ago I am no expert but this looks huge, perhaps something the size of the Krakatoa eruption.

miedpo4 days ago

Much smaller than Krakatoa so far. We'll have to see where it comes out on the VEI scale though. Krakatoa was really big, so I think it's pretty unlikely we will get close to that on this one.

The Tsunami they are guessing probably came from an earthquake or underwater landslide caused by the eruption, but the eruption doesn't really need to be huge to cause those. It'll be interesting to see once the eruption stops (if it's a landslide, you can usually see a crescent shaped formation on the volcano, although it may be underwater).

yesenadam4 days ago

From the Krakatoa page:

"The third explosion has been reported as the loudest sound heard in historic times. The loudness of the blast heard 160 km (100 mi) from the volcano has been calculated to have been 180 dB. Each explosion was accompanied by tsunamis estimated to have been over 30 metres (98 feet) high in places. ...The energy released from the explosion has been estimated to be equal to about 200 megatonnes of TNT, roughly four times as powerful as the Tsar Bomba"

divbzero4 days ago

The terminator in this video provides a good sense of time elapsed.

xarball4 days ago

Wow I'd never have known the line between day and night ever had a name, before you used that word! :)

tialaramex4 days ago

In some alternate universe 1984's "The Terminator" is a movie with a similar plot to "Pitch Black" in our universe (yes I know it's an eclipse in "Pitch Black").

dylan6044 days ago

The Ecliptic Terminator - "I'll be back!"

Andrew_nenakhov3 days ago

And you can be pretty sure it will be back, inevitably.

thematrixturtle4 days ago

That seems unlikely, since the magnitude was only 4.0. The relation between magnitude and actual impact is complex, but big ones tend to be 6+ and really big ones 8 or even 9.

easygenes3 days ago

The current magnitude estimate from the USGS is 5.8, with the caveat that, "...this event is calculated using techniques calibrated for earthquakes. The current magnitude is only a preliminary estimate for this volcanic event." [1]

cmurf4 days ago

What is the magnitude scale for volcanoes vs earthquakes? The site says this is magnitude 1.0 but without units or type. So I wonder if it's a tsunami potential specific scale?

alexander-litty3 days ago

I think the 1.0 magnitude is there as a placeholder. The advisories say to ignore it:

>Please disregard earthquake parameters

kingofpandora4 days ago

What are you basing your comparison of the two on I wonder?