oa Microtemperature Signals of the Earth's Crust

Temperature variations in the uppermost crustal layers result from several external as well as internal effects. These variations superpose the basic and rather stable energy flow from the earth's interior. Variations of the surface temperature, caused by diurnal, annual or long-term waves, jerks or other changes, dissipate into the subground to different extents and may be detected by measurements in the subground. Also environmental conditions, e.g. the cutting of tropical forest, cause a variation of the subsurface temperature as demonstrated with measurements.