Ignoring the role of latent heat, calculate the thickness of the active layer at the same site as in problem 1. Assume that the amplitude (half the full range) of the temperature swing at the surface is 15°C.

Problem 1

If the mean annual temperature is -12°C, the geothermal heat flux 40 mW/m², and the thermal conductivity of the near-surface Earth materials 2.5 W/m-K, what is the depth to the base of the permafrost?