7 ms·

Heard it go bang, 2600km away, echoing through the hills around our place at the top of the South Island of New Zealand. That's pretty staggering to think about

by RowanH 5y ago

Heard it go bang, 2600km away, echoing through the hills around our place at the top of the South Island of New Zealand. That's pretty staggering to think about it. Then to see other peoples Home Assistants around the world pick up the change in pressure on opposite sides of the planet. Mental, just mental...

belter 5y ago
Talk about long distance effects.... "Tonga volcanic eruption shockwave reached the Netherlands" https://nltimes.nl/2022/01/16/tonga-volcanic-eruption-shockwave-reached-netherlands https://nltimes.nl/2022/01/16/tonga-volcanic-eruption-shockw...
- wiredfool 5y ago
  There was a report from a climate org in Miami that they recognized the pressure pulse 9 times, once each ~35 hours since the eruption.
depereo 5y ago
My colleague's backyard weather station picked up the pressure wave in Christchurch several times as it repeatedly circled the globe. Sea levels in the upper south were a little 'odd', trending higher and more variably than usual, even if not by that much, for a week.
- jmspring 5y ago
  Here in California in the Sierra Nevada, a pressure variation was noticeable around 4am pacific.
  - kQq9oHeAz6wLLS 5y ago
    Hadn't thought of that. Just checked the data from my weather station, and there's a definite spike, followed by a drop. 30.16 inHg just before, 30.19 spike followed by an immediate drop to 30.14, then basically normalized again.
- sandworm101 5y ago
  I find it difficult to believe that even a massive eruption could literally push sea levels up or down in the surrounding area (waves /= sea level). Volcanoes are massive, but the energy to move cubic miles of water, water many hundreds or thousands of miles away, is at different level. Hurricanes can move water like that, but they do so with orders of magnitude greater energy (tens of thousands of nukes).
  - TheOtherHobbes 5y ago
    US tsunami monitoring has a record. https://www.tsunami.gov/previous.events/?p=03-19-09-Tonga https://www.tsunami.gov/previous.events/?p=03-19-09-Tonga
    - sandworm101 5y ago
      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: "Listed wave heights are maximum amplitude in cm (above sea level)." In other words, even tsunami waves heights are not changes to sea level.
      - TheOtherHobbes 5y ago
        I don't think anyone - except perhaps you - is suggesting that the eruption caused an actual rise in sea levels.
        andrewflnr 5y ago
        They were initially responding to a comment that said sea levels were slightly elevated for a week after the eruption. I have to agree that's pretty weird even for a tsunami.
      - 5y ago
LeoPanthera 5y ago
My back yard weather station picked up the shockwave here in the bay area: https://twitter.com/DavidCWG/status/1482451910154014720 https://twitter.com/DavidCWG/status/1482451910154014720 I had no idea that was even possible. Crazy stuff.
- madaxe_again 5y ago
  Mine picked it up too - in Portugal. Teeny little dip and crest, and I wasn’t sure until the meteorological station in a city 30km tweeted that they’d seen it too, and the times coincided (well, I was about a minute later) very neatly.
- Nekhrimah 5y ago
  > the bay area It's always interesting that anyone who lives in a "Bay", refers to their local as THE Bay. For this phenomenon, which is documented as circling the globe, who knows where this could be!
  - rjeli 5y ago
    no, there’s multiple areas with bays, there’s only one Bay Area.
    - yesenadam 5y ago
      > there’s only one Bay Area I suspected you were just assuming that, so I googled it, and found quite a few.
      - deleted 5y ago
        [deleted]
  - kenneth 5y ago
    The "Bay Area" is well known to refer (only) to the San Francisco Bay, while the "Greater Bay Area" is known to only refer to the Pearl River Delta Bay (HK, Macau, Guangdong). Other bays are typically named more specifically (e.g. Tokyo Bay, Monterey Bay, etc.). You'd be more on point if OP had referred to San Francisco as "The City" as many in the City do; since that's something that's also used in other cities like NYC. NB: current resident of the Greater Bay Area in China and former resident of the lesser Bay Area in California.
dylanz 5y ago
Takaka or Motueka? I used to live in that area. Golden Bay has a pretty unique geographical layout!
divbzero 5y ago
What did the “bang” sound like? Was it the sharp crack of thunder close by, the slower rumbling of distant thunder, the sound of fireworks exploding, or would some other description fit better?
- swamp40 5y ago
  Close up (next island over) it was a low loud fast boom like dynamite going off nearby. Over in an instant. From a Facebook video. Really strange that it would sound that way.
- muti 5y ago
  I also heard it in the north of the South Island of NZ. To me it sounded like very distant explosions, like a cannon firing, or avalanche control explosives. We heard multiple explosions over the span of a minute or two, presumably from the multiple paths the sound took as they all sounded the same.
- 8bitsrule 5y ago
  Here's a video with several pre-thuds then a VERY LOUD bang about 1m50s in ... 'sposed to be from Tonga. https://www.youtube.com/watch?v=KGV5payoRYs https://www.youtube.com/watch?v=KGV5payoRYs
throwaway894345 5y ago
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 frequencies which may or may not be the case...
- mkl 5y ago
  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.
  - Railsify 5y ago
    But there would be a spot where the pressure waves would cross?
    - thaumasiotes 5y ago
      > 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'.
    - layer8 5y ago
      Not necessarily. The set of points reached last by the waves could be multiple points, or a line, or multiple lines.
    - gnramires 5y ago
      I think so. I think there is necessarily a circle "eversion" (turning it inside-out) with a crease. Whatever is the point of the crease would hear sound from all directions. Even with something like a figure 8 collapsing wavefront, eventually one or more creases should form.
muti 5y ago
We also heard it while tramping on the thousand acre plateau just north of Murchison. It was very quiet, so we were lucky to be where we were with no noise pollution to drown it out. Though at the time we had no clue what it was, we joked about being in the Tomorrow series timeline.
spartanatreyu 5y ago
I live on the beach on the East coast of Australia. We had a marine tsunami warning. We were a few floors up so I wasn't really worried about myself. About 12ish hours after the initial eruption I thought that anything that was going to happened had all passed by hours ago and I was talking with friends online. Randomly I started hearing this white noise kind of sound (it sounded like the bubbling water of a kettle without any whistling). I took my headphones off and opened my door trying to find the source of the noise, thinking that the kettle had turned on. I looked outside and what was small surf conditions only 3 minutes before was extremely turbulent with white frothy waves moving in every direction. It looked like it was reacting to an earthquake but there was no movement in the ground. (I've felt an earthquake there before which is rare here but since our foundations are in the sands I've had the experience and could tell there was no earthquake in the ground on the morning after the eruption) Since the waves were moving in every direction, some of them were colliding head on. When this happened and the peaks and troughs were interacting in the right way they were shooting out jets of water spray at my eye level about 15m above sea level (I could tell since they were intersecting the horizon from my perspective). It continued for about a 30 seconds, calming down over another 30 seconds. After the surf had lowered itself to its previous levels, the whole top of the water going back about 50ish meters was covered in thick brown foam. All of the turbulent waves had dredged up the sand beneath it. The foam slowly disappeared over about an hour with the last bits being the foam that ended up getting washed ashore and out of the water's reach.
- wmeredith 5y ago
  Transport this event and yourself back to the bronze age and you could start a new religion with the other people who saw this.

by RowanH 5y ago

belter 5y ago

Talk about long distance effects.... "Tonga volcanic eruption shockwave reached the Netherlands" https://nltimes.nl/2022/01/16/tonga-volcanic-eruption-shockwave-reached-netherlands https://nltimes.nl/2022/01/16/tonga-volcanic-eruption-shockw...

wiredfool 5y ago
There was a report from a climate org in Miami that they recognized the pressure pulse 9 times, once each ~35 hours since the eruption.

depereo 5y ago

My colleague's backyard weather station picked up the pressure wave in Christchurch several times as it repeatedly circled the globe. Sea levels in the upper south were a little 'odd', trending higher and more variably than usual, even if not by that much, for a week.

jmspring 5y ago
Here in California in the Sierra Nevada, a pressure variation was noticeable around 4am pacific.
- kQq9oHeAz6wLLS 5y ago
  Hadn't thought of that. Just checked the data from my weather station, and there's a definite spike, followed by a drop. 30.16 inHg just before, 30.19 spike followed by an immediate drop to 30.14, then basically normalized again.
sandworm101 5y ago
I find it difficult to believe that even a massive eruption could literally push sea levels up or down in the surrounding area (waves /= sea level). Volcanoes are massive, but the energy to move cubic miles of water, water many hundreds or thousands of miles away, is at different level. Hurricanes can move water like that, but they do so with orders of magnitude greater energy (tens of thousands of nukes).
- TheOtherHobbes 5y ago
  US tsunami monitoring has a record. https://www.tsunami.gov/previous.events/?p=03-19-09-Tonga https://www.tsunami.gov/previous.events/?p=03-19-09-Tonga
  - sandworm101 5y ago
    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: "Listed wave heights are maximum amplitude in cm (above sea level)." In other words, even tsunami waves heights are not changes to sea level.
    - TheOtherHobbes 5y ago
      I don't think anyone - except perhaps you - is suggesting that the eruption caused an actual rise in sea levels.
      - andrewflnr 5y ago
        They were initially responding to a comment that said sea levels were slightly elevated for a week after the eruption. I have to agree that's pretty weird even for a tsunami.
    - 5y ago

LeoPanthera 5y ago

My back yard weather station picked up the shockwave here in the bay area: https://twitter.com/DavidCWG/status/1482451910154014720 https://twitter.com/DavidCWG/status/1482451910154014720 I had no idea that was even possible. Crazy stuff.

madaxe_again 5y ago
Mine picked it up too - in Portugal. Teeny little dip and crest, and I wasn’t sure until the meteorological station in a city 30km tweeted that they’d seen it too, and the times coincided (well, I was about a minute later) very neatly.
Nekhrimah 5y ago
> the bay area It's always interesting that anyone who lives in a "Bay", refers to their local as THE Bay. For this phenomenon, which is documented as circling the globe, who knows where this could be!
- rjeli 5y ago
  no, there’s multiple areas with bays, there’s only one Bay Area.
  - yesenadam 5y ago
    > there’s only one Bay Area I suspected you were just assuming that, so I googled it, and found quite a few.
    - deleted 5y ago
      [deleted]
- kenneth 5y ago
  The "Bay Area" is well known to refer (only) to the San Francisco Bay, while the "Greater Bay Area" is known to only refer to the Pearl River Delta Bay (HK, Macau, Guangdong). Other bays are typically named more specifically (e.g. Tokyo Bay, Monterey Bay, etc.). You'd be more on point if OP had referred to San Francisco as "The City" as many in the City do; since that's something that's also used in other cities like NYC. NB: current resident of the Greater Bay Area in China and former resident of the lesser Bay Area in California.

dylanz 5y ago

Takaka or Motueka? I used to live in that area. Golden Bay has a pretty unique geographical layout!

divbzero 5y ago

What did the “bang” sound like? Was it the sharp crack of thunder close by, the slower rumbling of distant thunder, the sound of fireworks exploding, or would some other description fit better?

swamp40 5y ago
Close up (next island over) it was a low loud fast boom like dynamite going off nearby. Over in an instant. From a Facebook video. Really strange that it would sound that way.
muti 5y ago
I also heard it in the north of the South Island of NZ. To me it sounded like very distant explosions, like a cannon firing, or avalanche control explosives. We heard multiple explosions over the span of a minute or two, presumably from the multiple paths the sound took as they all sounded the same.
8bitsrule 5y ago
Here's a video with several pre-thuds then a VERY LOUD bang about 1m50s in ... 'sposed to be from Tonga. https://www.youtube.com/watch?v=KGV5payoRYs https://www.youtube.com/watch?v=KGV5payoRYs

throwaway894345 5y ago

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 frequencies which may or may not be the case...

mkl 5y ago
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.
- Railsify 5y ago
  But there would be a spot where the pressure waves would cross?
  - thaumasiotes 5y ago
    > 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'.
  - layer8 5y ago
    Not necessarily. The set of points reached last by the waves could be multiple points, or a line, or multiple lines.
  - gnramires 5y ago
    I think so. I think there is necessarily a circle "eversion" (turning it inside-out) with a crease. Whatever is the point of the crease would hear sound from all directions. Even with something like a figure 8 collapsing wavefront, eventually one or more creases should form.

muti 5y ago

We also heard it while tramping on the thousand acre plateau just north of Murchison. It was very quiet, so we were lucky to be where we were with no noise pollution to drown it out. Though at the time we had no clue what it was, we joked about being in the Tomorrow series timeline.

spartanatreyu 5y ago

I live on the beach on the East coast of Australia. We had a marine tsunami warning. We were a few floors up so I wasn't really worried about myself. About 12ish hours after the initial eruption I thought that anything that was going to happened had all passed by hours ago and I was talking with friends online. Randomly I started hearing this white noise kind of sound (it sounded like the bubbling water of a kettle without any whistling). I took my headphones off and opened my door trying to find the source of the noise, thinking that the kettle had turned on. I looked outside and what was small surf conditions only 3 minutes before was extremely turbulent with white frothy waves moving in every direction. It looked like it was reacting to an earthquake but there was no movement in the ground. (I've felt an earthquake there before which is rare here but since our foundations are in the sands I've had the experience and could tell there was no earthquake in the ground on the morning after the eruption) Since the waves were moving in every direction, some of them were colliding head on. When this happened and the peaks and troughs were interacting in the right way they were shooting out jets of water spray at my eye level about 15m above sea level (I could tell since they were intersecting the horizon from my perspective). It continued for about a 30 seconds, calming down over another 30 seconds. After the surf had lowered itself to its previous levels, the whole top of the water going back about 50ish meters was covered in thick brown foam. All of the turbulent waves had dredged up the sand beneath it. The foam slowly disappeared over about an hour with the last bits being the foam that ended up getting washed ashore and out of the water's reach.

wmeredith 5y ago
Transport this event and yourself back to the bronze age and you could start a new religion with the other people who saw this.