two kilometers or so down in most places there are these incredibly hot rocks, ’cause the interior of the earth is extremely hot, several million degrees
– Al Gore (Nobel Laureate)
Before its closing in 2002 Homestake Gold Mine was the oldest, largest and deepest mine in the Western Hemisphere, reaching more than 8000 feet below the town of Lead.
http://www.homestakevisitorcenter.com/
8000 := 1.51515 miles
Am I being too fussy with accuracy ?
You are using the wrong units. 8,000 feet is 2.4 kilometers
Damn your kilometers!!
I got the impression Al gore said miles which is bad enough, But he said Two kilometers, I checked about and found this.
“The geothermal gradient is usually quoted as 25–50 degrees Celsius per mile of depth in normal terrain (not, e.g., in the crater of Kilauea). Two kilometers down, therefore, (that’s a mile and a quarter if you’re not as science-y as Al) you’ll have an average gain of 30–60 degrees — exploitable for things like home heating, though not hot enough to make a nice pot of tea. The temperature at the earth’s core, 4,000 miles down, is usually quoted as 5,000 degrees Celsius, though these guys claim it’s much less, while some contrarian geophysicists have posted claims up to 9,000 degrees. The temperature at the surface of the Sun is around 6,000 degrees Celsius, while at the center, where nuclear fusion is going on bigtime, things get up over 10 million degrees.
If the temperature anywhere inside the earth was “several million degrees,” we’d be a star”
SOURCE: http://www.nationalreview.com/corner/190379/innumerate-al/john-derbyshire