Resistivity surveying in geothermal exploration with an application to the Eyjafjördur low-temperature area, N-Iceland

Abstract

Geothermal exploration involves geology, geochemistry and geophysics. In geophysical exploration, resistivity surveying plays the most important role in delineating the reservoir. The parameters that control the geothermal system show a strong response to electrical resistivity. The resistivity methods that are mostly used in geothermal exploration in Iceland are TEM (Transient ElectroMagnetics) and MT (MagnetoTellurics). The application of these methods is discussed in this report together with an example from the Eyjafjördur low-temperature area in N-Iceland. The resulting resistivity cross-sections and resistivity depth slices show a shallow lying low-resistivity layer and a deep lying low-resistivity anomaly towards the end of the cross-sections. The result of this work has been compared with results from Flóvenz and Karlsdóttir (2000) which interpreted TEM data from the same area. The results are also compared with borehole data and stratigraphy.