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How big was the Tonga eruption?

graphics.reuters.com

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Re: How big was the Tonga eruption?

#141

Post by brendyn »

acchow wrote: post #125
Robotbeat wrote: post #88

Earlier quoted context omitted.

The 6-10MT estimate is really a lower bound based on the amount of material moved from the island. A more reliable estimate is based on the overpressure, which was significantly larger than the Tsar Bomba (also exploded over an island) which was 50MT. https://text.npr.org/1074438703 That said, the amount of SO2 was fairly low, so the climate impact not likely to be large.

Any idea if this will have a measurably effect on climate change?

I heard from an Anton Petrov video it would reduce the planets average temperature by half a degree for some time, but I don't know where he got that info from.

Re: How big was the Tonga eruption?

#143

Post by jameshart »

bt1a wrote: post #89
lelandbatey wrote: post #47

Earlier quoted context omitted.

Yes, they did use transparent shadows. You can tell because the images are not GIF's, they're actually a sequence of PNG images overlayed atop other PNG images. There's the base satellite image of the area, then the frames-of-explosion-with-transparency overlayed atop them. You can confirm this by right clicking on the image and choosing "open image in new tab", which will (usually) open this final frame in a new tab…

I tried to save one of the "gifs" to share with a friend and was quite upset that I found myself with a png. Interesting technique. Do you think this was done to have better quality animated images? GIF compression isn't amazing (relative to WebM at least)

Very gratified they didn’t just post these as rendered gifs.

Imagine the social media scare you could generate in a year or so after everyone has forgotten about this eruption by sharing a graphics.reuters.com URL for one of these animations that appears to show a satellite image sequence of a massive mushroom cloud obliterating the Korean Peninsula or the Sinai with a breathless ‘LOOK WHAT REUTERS JUST REPORTED!!!’ caption.

It’s really important for reputable sources posting images to think about the fake news potential of them getting shared out of context.

Re: How big was the Tonga eruption?

#144

Post by neuronic »

Tuna-Fish wrote: post #84
thomascgalvin wrote: post #77

Earlier quoted context omitted.

That is absolutely mind-boggling.

Mount Tambora is estimated to have been about 33GT. That one messed up weather globally for two years.

And it's suspected to have had an impact on Napoleons Waterloo disaster by changing the weather...

Re: How big was the Tonga eruption?

#145

Post by TheOtherHobbes »

sandworm101 wrote: post #140
TheOtherHobbes wrote: post #135

Earlier quoted context omitted.

US tsunami monitoring has a record. https://www.tsunami.gov/previous.events/?p=03-19-09-Tonga

A tsunami is a wave. Not sea level. Waves literally come and go over a period of seconds to minutes. They wobble back and forth without actually moving much water. Sea levels move on the order of hours and days and involve the physical movement of literally hundreds of cubic-miles of water. Raising or lowering a sea level measurement (not a temporary wave) requires far more energy than a volcano. From the link: "List…

I don't think anyone - except perhaps you - is suggesting that the eruption caused an actual rise in sea levels.

Re: How big was the Tonga eruption?

#146

Post by Railsify »

mkl wrote: post #127
throwaway894345 wrote: post #126

Earlier quoted context omitted.

I've heard that the Krakatoa eruption was so loud that the sound wave reverberated around the globe several times. I assume that means if you're on exactly the other end of the world, the sound is coming at you from every direction? Similarly, no matter where you are on earth, the sound is coming at you from different directions at different times? Of course, I'm assuming that the sound wave was in audible frequencie…

Even exactly on the other side of the world, the sound will reach you at different times from different directions due to different pressures, temperatures, mountains, etc. on the way.

But there would be a spot where the pressure waves would cross?

Re: How big was the Tonga eruption?

#147

Post by taneq »

divbzero wrote: post #119
busyant wrote: post #105

This is an excellent lesson in how shitty my sense of geographic scale is. I would have guessed that the size of the eruption was on par with the size of a small city.

The Pacific Ocean is ginormous (I think that’s the technical term?) I often find myself surprised when I spin a globe (physical or virtual) and compare the expanse of the ocean to my neighborhood of the planet. The scale also makes the history of Polynesian seafaring all that more incredible.

Some experts prefer ‘humongous’. ;)

Re: How big was the Tonga eruption?

#148

Post by phist_mcgee »

michilehr wrote: post #142

My cheap weather station has recorded the blast wave three times. https://michilehr.de/the-eruption-of-hunga-tonga-volcano-and...

I find the mix of your commas and periods in numbers a little confusing.

>305,8 m/s but also 8.7m and ~1.4 hPa.

I know that Europeans have a different notation to Americans, but is there a rule here I am missing?

Re: How big was the Tonga eruption?

#149

Post by thaumasiotes »

Railsify wrote: post #146
mkl wrote: post #127

Earlier quoted context omitted.

Even exactly on the other side of the world, the sound will reach you at different times from different directions due to different pressures, temperatures, mountains, etc. on the way.

But there would be a spot where the pressure waves would cross?

> But there would be a spot where the pressure waves would cross [simultaneously]?

There could be, but it's not immediately obvious that there has to be.

It does seem like certain points would need to be on 'cusps' of the wavefront, though, so something like getting the wave from the north and the northeast 'simultaneously'.

Re: How big was the Tonga eruption?

#150

Post by tacker2000 »

phist_mcgee wrote: post #148
michilehr wrote: post #142

My cheap weather station has recorded the blast wave three times. https://michilehr.de/the-eruption-of-hunga-tonga-volcano-and...

I find the mix of your commas and periods in numbers a little confusing. >305,8 m/s but also 8.7m and ~1.4 hPa. I know that Europeans have a different notation to Americans, but is there a rule here I am missing?

No, there is no missed rule, the comma is the only official decimal separator in these parts. But I can relate to the the OP. Us here in the comma world are forever converting numbers in CSV and Excel files back and forth so as to display them in a proper number format. It’s like that darned USB port, you have to flip it 3 times to get it right.
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