I might add that any significant slowing of the earths rotation would be immediately followed by an adjustment of the earths crust....
but I would say maybe a day.
but I would give it maybe an hour.
Hi Paul. That is simply not the case.
Speedy reshaping of the equatorial bulge would require the breaking of most of the chemical bonds that are holding the solid together (remember the mantle is a solid and, due to its compressed state, is stronger and stiffer than steel).
This quick breaking of such chemical bonds is usually called melting.
In this situation, gravity does not provide enough energy to melt all this rock, or even partially melt it.
There is enough energy to break some of these bonds and this leads to the very, very, slow flow of the mantle (and, of course, this has led many people to a belief in the very silly theory of plate tectonics).
So, in this way, over a very long period of time, gravity gets the job done.
