Joint 1-D inversion of TEM and MT data - example from Krýsuvík high-temperature area, SW-Iceland

Abstract

Krýsuvík is one of the high-temperature geothermal areas on the Reykjanes peninsula in SW- Iceland. In order to explore the geothermal potential of the area, 96 MT soundings were performed and more than 200 TEM soundings during the last few years. This report presents the results of a survey of one profile consisting of 10 MT soundings and 10 TEM soundings. Joint 1-D inversion of the TEM and MT data was done in order to correct the static shift affecting the MT soundings. The data were acquired by the geophysical team of ISOR for HS Orka and the data were processed, inverted and interpreted using different software like: SSMT2000, MTEditor, TEMX and TEMTD. The results of 1-D joint inversion given in this report are presented as cross-sections of the resistivity down to different depths. The 1-D inversion of TEM soundings reveals the subsurface resistivity down to a depth of less than 1 km, while the joint inversion of the TEM and the MT data reveals the subsurface resistivity down to a depth of several km. The geothermal reservoir is presumably located below 400 m b.s.l. according to the resistivity cross-section based on TEM soundings. The depth dimensions of the reservoir have been quite well defined by cross-sections based on MT soundings. Three favourable drilling locations are proposed to explore the geothermal resource.