Barring the immense pressure and lack of oxygen, I’d like a nice 75 degrees or so
In: Planetary Science
It’s pretty much impossible to pick a specific depth and say that it’s “just right” since the temperature gradient between the crust and the core isn’t the same at every point. Some places are hotter while some places are colder. For example, near oceanic subduction zones, the part of the crust that is being “subducted” is significantly colder than the surrounding crust. Likewise, there are plenty of places (Hawaii being the prototypical example) of “hot spots” where magma is far closer to the surface than usual meaning it would be a significantly hotter area of the crust.
That said, even when an area is “colder,” that’s only relatively speaking. Even “cold” areas within the crust/core would be extremely hot by our standards. The effects of the surface temperature due to the sun/climate are virtually non-existent once you reach about 20 meters deep in the crust. From there, it’s mostly geothermal and radiation heating that determines the temperature. As a *general* rule, the temperature increases by about 25-30 °C for every kilometer of depth. Again, this isn’t always true, though, and in some places, the temperature can *decrease* as you go deeper.
In short, though, you could probably go about a km on average before the temperature would start to become unbearable for humans. In some places, you might be able to get deeper, while in others, you wouldn’t be able to go even 10 meters without hitting superheated rock.
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