Heat From Earth’s Interior

Earth’s interior

http://www.seismo.unr.edu/ftp/pub/louie/class/100/interior.html

Earth’s crust

the Earth has a radius of about 6370 km …
http://www.seismo.unr.edu/ftp/pub/louie/class/100/interior.html

The Earth’s outermost surface is called the crust. The crust is typically about 25 miles thick beneath continents, and about 6.5 miles thick beneath oceans. …
http://www.thetech.org/exhibits_events/online/quakes/…/crust.html

The earth’s crust is the thickest below the continents, with an average of about 20 to 25 miles (30 to 40 km) and with a maximum of 45 miles (70 km). …
mediatheek.thinkquest.nl/~ll125/en/crust.htm