One-dimensional interperatation of Schlumberger and TEM resistivity data with examples from Torfajökull, S-Iceland

Abstract

In this report, a brief discussion covering the basic principles, field techniques, instrumentation and interpretation of Schlumberger and TEM soundings is given. As an example, Torfajökull geothermal field in S-Iceland was chosen. 33 TEM soundings from the field were interpreted using a one-dimensional inversion programme. The quality of the Schlumberger data (13 soundings) was found to be low. From the results of the TEM soundings, seven resistivity profiles and four iso-resistivity maps were made. The results show a well defined resistivity anomaly. Based on experience from other high-temperature geothermal fields in Iceland, the resistivity structure is interpreted in terms of geothermal activity. The inferred geothermal activity can be correlated with a caldera found in the survey area.