4 ms·

I read an entire book about the Tunguska explosion when I was in junior high, but it's interesting that astronomers now think an event like this could happen ev

by smoyer 11y ago

I read an entire book about the Tunguska explosion when I was in junior high, but it's interesting that astronomers now think an event like this could happen every 300 years.

krylon 11y ago
One interesting detail I found, I think, on Wikipedia, is that if the meteor had hit about four hours later, due to Earth's rotation, it would have roughly hit Saint Petersburg. If such events happen so frequently, we're pretty lucky so far. Given that much of Earth is covered in water, I could imagine a lot of these simply hit the ocean, but I don't know what would happen if it hit close to the coast.
- saiya-jin 11y ago
  a simple hit of ocean might be more devastating than hitting uninhabited parts of taiga. think about massive tsunami (at least that's what I would expect, depending on the impact force of course)
  - masklinn 11y ago
    > think about massive tsunami (at least that's what I would expect, depending on the impact force of course) You'd need something way more powerful than the Tunguska event; ignoring that Tunguska was most likely an airburst (not an impact), its estimated yield was about twice the Castle Bravo yield which did generate relatively inconsequential waves compared to the rest of its issues. A "true" tsunami requires absolutely ridiculous amounts of water displacements, that doesn't happen with anything short of existential-risk impactors. Operation Hardtack confirmed that nuke-level energy didn't come close: there isn't enough displacement and that displacement is very temporary.
  - gus_massa 11y ago
    Some similar analysis: "Mariana Trench Explosion" https://what-if.xkcd.com/15/ https://what-if.xkcd.com/15/ I think that if the asteroid is big enough to make a massive deadly tsunami, it will also create a very big mess if it hit the land.
  - goldenkey 11y ago
    water is very dampening. tsunamis are from sustained force
    - cr1895 11y ago
      It's literally wet! You'll get dampened indeed. Tsunamis are generated by water displacement from e.g. underwater seismic activity or a massive landslide. Wind-driven waves or tides would be driven by sustained forces. Whether or not an asteroid can/has cause(d) a tsunami I don't know.
      - raattgift 11y ago
        A sufficiently energetic meteor strike will cause a high enough amplitude wave to qualify as tsunamis (and which therefore would produce destructive effects onshore). Exact modelling is tricky, but that sort of thing appeals to some geophysicists. Funny headlines, serious research: http://news.ucsc.edu/2003/05/355.html http://news.ucsc.edu/2003/05/355.html http://www.livescience.com/49298-asteroids-causing-tsunamis.html http://www.livescience.com/49298-asteroids-causing-tsunamis....

by smoyer 11y ago

I read an entire book about the Tunguska explosion when I was in junior high, but it's interesting that astronomers now think an event like this could happen every 300 years.

krylon 11y ago

One interesting detail I found, I think, on Wikipedia, is that if the meteor had hit about four hours later, due to Earth's rotation, it would have roughly hit Saint Petersburg. If such events happen so frequently, we're pretty lucky so far. Given that much of Earth is covered in water, I could imagine a lot of these simply hit the ocean, but I don't know what would happen if it hit close to the coast.

saiya-jin 11y ago
a simple hit of ocean might be more devastating than hitting uninhabited parts of taiga. think about massive tsunami (at least that's what I would expect, depending on the impact force of course)
- masklinn 11y ago
  > think about massive tsunami (at least that's what I would expect, depending on the impact force of course) You'd need something way more powerful than the Tunguska event; ignoring that Tunguska was most likely an airburst (not an impact), its estimated yield was about twice the Castle Bravo yield which did generate relatively inconsequential waves compared to the rest of its issues. A "true" tsunami requires absolutely ridiculous amounts of water displacements, that doesn't happen with anything short of existential-risk impactors. Operation Hardtack confirmed that nuke-level energy didn't come close: there isn't enough displacement and that displacement is very temporary.
- gus_massa 11y ago
  Some similar analysis: "Mariana Trench Explosion" https://what-if.xkcd.com/15/ https://what-if.xkcd.com/15/ I think that if the asteroid is big enough to make a massive deadly tsunami, it will also create a very big mess if it hit the land.
- goldenkey 11y ago
  water is very dampening. tsunamis are from sustained force
  - cr1895 11y ago
    It's literally wet! You'll get dampened indeed. Tsunamis are generated by water displacement from e.g. underwater seismic activity or a massive landslide. Wind-driven waves or tides would be driven by sustained forces. Whether or not an asteroid can/has cause(d) a tsunami I don't know.
    - raattgift 11y ago
      A sufficiently energetic meteor strike will cause a high enough amplitude wave to qualify as tsunamis (and which therefore would produce destructive effects onshore). Exact modelling is tricky, but that sort of thing appeals to some geophysicists. Funny headlines, serious research: http://news.ucsc.edu/2003/05/355.html http://news.ucsc.edu/2003/05/355.html http://www.livescience.com/49298-asteroids-causing-tsunamis.html http://www.livescience.com/49298-asteroids-causing-tsunamis....