A GIS-Based Analysis of Earth’s Crust Temperature at Depth for Geothermal Energy Exploration in Afghanistan

Abstract

Abstract-The future green world, without of greenhouse gases, is possible to produce the electricity from the renewable energy resources. The geothermal is one of the most potential clean energy sources to be developed in the next century. The geothermal energy potential study needs the temperature value and amount of stored heat in the underground rocks. The purpose of this research is to determine the earth's crust temperature at the depth of 3.5 to 10.5km for geothermal energy potential calculation in Afghanistan. The temperature at depth prediction model is based on the tectonic ages, tectonic activity, geological structures, and hot spring data. To achieve this goal, in GIS, the earth's crust thickness, sediment thickness, surface heat flow, mantle heat flow, and surface temperature have been mapped. The temperature calculation formulas, as a function of depth, were applied in GIS model to estimate the temperature at depth. The analysis contains the sediment and basement contribution along with surface temperature correction considering the constant thermal conductivity and radioactive heat generation in the crust. The resulting maps are plotted for each km of depths from 3.5 to 10.5km. The calculation result is in the range of; minimum 39°C and maximum 347°C average temperature at the depth of 3.5km and 10.5 km respectively. The huge geothermal energy (power production) is available; First in Helmand, Kandahar, and Herat provinces, moreover, in northern and eastern deeper sedimentary region of the country at the depth of 3.5km. Second in the all known geothermal fields of the country until the depth of 5 km.Index Terms-Afghanistan, geothermal energy, earth's crust temperature, geographical information system.