Thermal Diffusivity -- from Eric Weisstein's World of Physics

The constant in the heat conduction equation

describing the rate at which heat is conducted through a medium. It is related to thermal conductivity k, specific heat , and density by

and has units of cm² s^-1. For common rock material, 10^-2 cm² s^-1. A high thermal diffusivity inhibits convection.

Heat Conduction Equation, Prandtl Number, Thermal Conductivity