Penguins are not evil, just misunderstood. Proof of this is there are no homosexual penguins.
Penguin shill detected
Ok, so I read the shadow zone link, and from what I understand it is caused by water in the crust? Is that correct? If that is the case, then I don't know what the question is, since there is definitely water under the ground on the flat earth.
There is definitely some water in the crust, but water has nothing to do with shadow zones.
there are two types of waves generated by an earthquake:
S-waves and P-waves
S-waves can pass ONLY through solids.
P-waves can pass through both solids and liquids. (but their intensity is decreased a bit when passing through liquids)
A shadow zone is an area opposite of the earthquake (assuming the Earth is round) that lacks S-waves and has P-waves who's intensity is decreased.
So since the crust and the mantle are mostly solid, both waves travel through them without any problem. The inner core is solid, but the outer core is liquid.
Because the outer core blocks the S-waves, they will not appear at the opposite side of the world.
For example if an earthquake happened in Spain, a shadow zone would appear around New Zealand.
The FET does not explain this.