In article <1c6aeebc-7004-44e6...@googlegroups.com
> After the moon formed, due the proposed Theia off-angle
> collision with the new Earth, it was vastly closer to its
> parent planet; maybe 3 roche radii (?). Just how powerful
> and high would the resulting tides been on Earth? I include
> any oceans and tides within the solid (crustal?) Earth.
> Would such tides have contributed greatly to any plate
> tectonics and volcanism? Would this have contributed
> to the ultra-hot and highly fluid komatiite lavas?
Tidal force is inversely proportional to the cube of the distance, so
they would be much higher. But was there water then? The solid Earth
also has (much smaller) tides, and they would have been higher as well.
The scaling isn't simple, though; in the case of solid-mass tides, the
extreme viscosity plays a role, and also the shape of the coastline and
so on also play a role, and its effect would not scale simply with the
See also https://astronomy.stackexchange.com/questions/39109/how-high-were-the-tides-back-when-the-moon-was-much-closer-to-earth