12 to 20 km
depends exactly WHERE you drill, but in general the poles are colder so you gotta drill deeper.
IF there were a hotspot (or even a warm one), it would be less, but nobody's found a valid hotspot yet...
Space/Science » in reply to How deep...
depends exactly WHERE you drill, but in general the poles are colder so you gotta drill deeper.
IF there were a hotspot (or even a warm one), it would be less, but nobody's found a valid hotspot yet...