Surface heat flux density map 1: 100,000

The map shows the heat flux density in mW / m2, which is mostly a reflection of the heat transfer from the Earth's interior to the surface; the heat flux is determined by measuring the temperature gradient in 111 wells and by measuring the thermal conductivity on rock samples from most of these wells; since the mentioned measurements refer only to the upper 3 to 5 km of the Earth's crust, they represent surface heat flux density. The map considers topographic correction and does not include significant convection zones.