Ratio of true vertical component of regional Earth's Heat Flux j_z({\bf r}) to the subsurface Thermal Conductivity \lambda_e({\bf r}) at a certain subsurface point {\bf r}:
(1) | G_T({\bf r}) = \frac{j_z({\bf r})}{\lambda_e({\bf r})} |
Fig. 1. Schematic view of the Earth's Geothermal Temperature Gradient. |
The most common value of Unbiased Geothermal Temperature Gradient (GT) away from tectonic plate boundaries is:
G_T = 0.025 ÷ 0.030 \, \rm °C/m.
See Also
Geology / Geothermal Temperature Field
[ Geothermal Temperature Gradient (GradT) ] [ Geothermal Temperature Profile (TG) ]