| Husband of one of the researchers here. These scientific cruises are a huge undertaking, and the fact that the team managed to do this during Covid was an achievement by itself. Shipping containers filled with obscure tech to a different country that you'll then send to the bottom of the ocean will surely raise eyebrows at customs. Then there was the self-isolating, and working in shifts so different teams can do different kinds of lander deployments (and pick them back up), etc. Incredible! Some of the tech that's put on these kinds of research ships is pretty crazy, too. For example, they put spherical glass floats on landers that go to the bottom of the ocean[0]. Weights pull the lander down, and when the lander receives a signal it detaches the weights[1] so the floats pull it back up. These glass floats are pretty big and need to be able to resist a huge amount of pressure at depths of multiple kilometers. If I recall correctly, if one of these spheres breaks, due to the pressure, the collapse of the water on all sides of the sphere results in as much energy released as an atomic bomb. As to this research: the researchers initially weren't too happy to find this. First they doubted if it was correct, but it's actually worse when you find out it is in fact correct but it goes against everything in biology books: how the hell are you going to explain this to people? [0] I'm not sure if a lander like that was used in this research btw, it's just an example that I found interesting. [1] One time, I think on a different cruise, researchers didn't have enough weights to do an extra deployment, so they got weights from the gym on the ship and put them on the lander. There's a whole bunch of these kinds of interesting/funny stories in different fields of science, could be nice if someone were to collect them somewhere. |
That can't be true, but perhaps you saw something about temperatures which resembled those from a nuclear-bomb instead? (The key being that much much less mass is getting heated, and stays that way for a much shorter time.)
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One quick set of reasoning is this: Energy cannot be created or destroyed, and there's no reason to think the popping-bubble is causing seawater to undergo nuclear fusion, so the limit is whatever it takes for someone to repeatably set up the situation. (So basically the energy to dropping ballast-and-bubble to the bottom of the sea, popping the bubble, and then pulling the ballast back up.) Tedious, but hardly nuclear-bomb territory.
A second approach is to imagine the collapse as a giant column of water falling like weight into the gap. Imagine a magic-glass box 1x1x1 meter holding a vacuum, sunk 10km below the surface. That's 10,000 m^3 of water and roughly ~10,000kg of mass poised to fall 1m. Gravitational potential energy: ~98 kilojoules.
For comparison, that's the energy of ~3 liters of gasoline, although getting it to explode in a similarly-simultaneous way would be tricky. (Power = Energy / Time.) In contrast, the Hiroshima explosion was ~63 terajoules.