How deep can a person be below the earth if the temp is -70 above the earth to be safe.?

Question

For every foot or degree you go below earth how far do you have to be to survive sub zero temps above earth. And is there some kind of chart some place to determine or compare temps above and below the earth.

Answer 1

You are referring to the geothermal gradient.

It is unrelated to air temps and only refers to the Earth, not the atmosphere.

Assuming temps like that were possible outside of Arctic conditions, you could probably just go in a cave. They are about 50-56 F regardless of the air temperature

Answer 2

-70 aboveground would only occur in the arctic or antarctic, where the subsurface is permafrost. Generally it depends on where you are as to what the subsurface temps are.

Answer 3

Eskimos survive very well in igloos at very low temperatures. -70°F outside +30°F inside. Naturally they need warm clothing.