This is what I’m visualizing:
A liquid ocean pressed against the inner side of Europa’s ice crust, during high tide. Then the tide shifts and the water rushes away, leaving a gigantic hollow shell high above the ocean’s surface, like a vast dome stretching towards the horizon in all directions, in total darkness.
Meanwhile, the tidal bulge has rushed halfway across the hemisphere, the water is now pressing against the ice crust there.
If the Jovian system’s tidal forces can stretch and knead Io’s mantle like silly putty, its’ rocky surface rising and falling as much as 100 meters (about 300 feet) each tidal cycle… I can’t even imagine how violently the water may slosh under Europa’s ice crust.
One final note: considering that Europa is tidally locked with Jupiter, and it is Ganymede and Callisto that can pull in other directions, how long are the tidal cycles there? The principle is like on Earth, but there are extra gears in the mechanism, so to speak, different high and low tides may vary widely between each other.
Why would you assume the ice isn’t being squished/stretched as well?
Exactly. The crust would likely experience similar effects as the liquid beneath, probably fracturing into plates and moving on the tide. There is visual evidence of the surface expanding, contracting, and fracturing with tidal forces
Where would the air come from, pray tell?
It would most likely be locally available molecules in the gaseous phase.
I’m going to express some solidarity with OP here. I feel like there is some unconscious bias affecting their visualisation, in no small part due to my first blush reaction being “that kinda makes sense”. On Earth at sea level we are used to ice being rigid enough that we don’t expect tidal forces to distort it at the same rate as it affects neighbouring water, however as OP pointed out tidal forces in the Jovian system are colossal compared to what we are familiar with.
We also expect our atmosphere to rush in to fill any available space, even though that’s only true at surface level (give or take a few meters) its counter intuitive to think about different paradigms of atmosphere if you haven’t trained those reflexes.
Its kinda like the hottest parts of he Earths core being hotter than a large amount of the surface of he sun. That boggles my mind, but once I understood the caveats of that statement and the science involved it made a lot more sense, even if it wasn’t intuitive.
