Geothermal map – The expected depth map to the 90 °C isothermal

The underground geothermal conditions, regardless of the position of the aquifers, are shown with suitable geothermal maps. This map shows the expected depths to the 90 °C isotherm and is made with data from 191 wells. In a way, it is inverse to those ordinary temperature charts that show temperatures at certain depths. It is made on the basis of measured temperatures in accessible wells throughout the country. However, since the temperature field depends on the geological composition in depths and tectonic characteristics, the course of isoliniums is the result of numerous influences such as thermal conductivity of rocks, permeability and cracking of rocks, all of which are reflected in measured well temperatures. The distribution of wells, which were useful for temperature measurements, is very uneven and varies in depth. The map of depths to the 90 °C isotherm shows a positive anomaly in the north-eastern part of Slovenia. As a result of the thinner Earth’s crust in this area and the higher conductive heat flow from the Earth’s mantle, there are the highest temperatures, and vice versa are the smallest depths to the 90 °C isotherm.