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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 s

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.
    - thaumasiotes 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. You should be aware that tsunamis behave in the way you're calling "sea level", and not in the way you're calling "wave". It's true that a tsunami is a wave, but it's not true that they come and go over a period of minutes, or that they fail to move much water. They're very large.
      - sandworm101 5y ago
        Some of them, specifically those involving undersea plates moving upwards, but even those do settle out quickly. That is why the term literally means "port waves" because they bypass normal wave protections and move into ports, similar to how tidal bores move up rivers. But the comment above spoke of sea levels being impacted for many days, something beyond even thrust tunamis and more akin to hurricanes.
    - lnwlebjel 5y ago
      Think of it more like a very long period wave, much like a tide, but on a much shorter time period than the tide. Tides, waves (periods on the order of seconds), and tidal waves (or tsunamis) are all fluctuations in sea level. Water can be moved when the waves encounter enclosed bays or harbors. Think of the water level dropping 3 ft over 20 minutes in front of a harbor entrance and imagine the currents that can result. Here's an example of observations from coastal California (red line shows sea level measured every 6 minutes: https://tidesandcurrents.noaa.gov/waterlevels.html?id=9412110&bdate=20220114&edate=20220115&units=standard&timezone=LST/LDT&interval=6 https://tidesandcurrents.noaa.gov/waterlevels.html?id=941211... It is truly amazing - I'm not surprised that it's hard to believe.
  - NamTaf 5y ago
    That's from 2009. I can't figure out how to navigate the site so as to find the 2022 event.

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.
  - thaumasiotes 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. You should be aware that tsunamis behave in the way you're calling "sea level", and not in the way you're calling "wave". It's true that a tsunami is a wave, but it's not true that they come and go over a period of minutes, or that they fail to move much water. They're very large.
    - sandworm101 5y ago
      Some of them, specifically those involving undersea plates moving upwards, but even those do settle out quickly. That is why the term literally means "port waves" because they bypass normal wave protections and move into ports, similar to how tidal bores move up rivers. But the comment above spoke of sea levels being impacted for many days, something beyond even thrust tunamis and more akin to hurricanes.
  - lnwlebjel 5y ago
    Think of it more like a very long period wave, much like a tide, but on a much shorter time period than the tide. Tides, waves (periods on the order of seconds), and tidal waves (or tsunamis) are all fluctuations in sea level. Water can be moved when the waves encounter enclosed bays or harbors. Think of the water level dropping 3 ft over 20 minutes in front of a harbor entrance and imagine the currents that can result. Here's an example of observations from coastal California (red line shows sea level measured every 6 minutes: https://tidesandcurrents.noaa.gov/waterlevels.html?id=9412110&bdate=20220114&edate=20220115&units=standard&timezone=LST/LDT&interval=6 https://tidesandcurrents.noaa.gov/waterlevels.html?id=941211... It is truly amazing - I'm not surprised that it's hard to believe.
- NamTaf 5y ago
  That's from 2009. I can't figure out how to navigate the site so as to find the 2022 event.