such as determining water movement in radioactive waste and in locating buried land mines. Uses The thermal inertia of the soil enables the ground to be used for underground thermal energy storage. Solar energy can be recycled from summer to winter by using the ground as a long term store of heat energy before being retrieved by ground source heat pumps in winter. Changes in the amount of dissolved organic carbon and soil organic carbon within soil can effect its ability to respirate, either increasing or decreasing the soils carbon uptake. Furthermore, MCS design criteria for shallow loop ground source heat pumps require an accurate in situ thermal conductivity reading. This can be done by using the above-mentioned thermal heat probe to accurately determine soil thermal conductivity across the site. References Thermal properties, soil Thermodynamic properties