Nothing to do with cars but

[Q45tech]

maybe useful to some engineers.Just a useful fact I gleened from my study of futire energy sources:

"This is because of something called the geothermal gradient. This is one of the last, almost untapped, sources of energy that we have. While it varies around the world, the numbers where I come from are these: At 500 ft below the ground the rock temperature is 60 degrees F. For every 60 ft you go further down, the rock temperature goes up a degree. So that if you are 1100 ft down, then the temperature is 1100 - 500 = 600 (extra depth)/60 = 10 extra degrees + 60 = 70 degrees F. And at 8,000 ft (a deep gold mine) it will be ((8000-500)/60) +60 = 185 degrees--which is why they refrigerate the air in mines that go that deep."

[elwesso]

Where are those numbers relavent?

How practical is it to drill 8000FT for use of geothermal heat/power?

[ravera]

agreed, as much of a PITA as it would seem to be, I feel that distance from location to center of the core would be a much more precise measurement than distance from top of the crust to location...

That said, I'd only need like a 10000 foot deep hole to get steam power, totally feasable...