Ask A Scientist General Science Archive

Question:
How hot is the Earth's core, approximately, and how can it be measured?
 kathleen n mecham

Answer:
There is no way to measure the temperature at the Earth's core
directly.  We know from mines and drill holes that, near
the surface of the Earth, the temperature increases by about
1 degree Fahrenheit for every 60 feet in depth.  If this
temperature increase continued to the center of the Earth, the
Earth's core would be 100,000 degrees Celsius!

But nobody believes the Earth is that hot; the temperature increase
must slow down with depth and the core is probably
about 3000 to 5000 degrees Celsius.

This estimate of the temperature is derived from theoretical
modeling and laboratory experiments.  This work is very
difficult (and speculative) since nobody can reproduce
in a laboratory the high temperatures and pressures that
exist in the core.  Also it is not known exactly what
the core is made of.

-Grant