A new conceptual model of the Icelandic crust in the Hengill geothermal area based on the indirect electromagnetic geothermometry

Electromagnetic Sounding of Geothermal Areas

“…This can be accomplished in different ways, the most common being an interpretation of the resistivity distribution taking into account geophysical constraints in terms of the temperature well records and gravity or seismic velocity maps (Galanopoulus et al, 1991;Takasugi et al, 1992;Bibby et al, 1995;Correia and Jones, 1997;Gunderson et al, 2000;Talebi et al, 2005;Ushijima et al, 2005;Harinarayana et al, 2006;Spichak et al, 2007b;Spichak et al, 2013). This can be accomplished in different ways, the most common being an interpretation of the resistivity distribution taking into account geophysical constraints in terms of the temperature well records and gravity or seismic velocity maps (Galanopoulus et al, 1991;Takasugi et al, 1992;Bibby et al, 1995;Correia and Jones, 1997;Gunderson et al, 2000;Talebi et al, 2005;Ushijima et al, 2005;Harinarayana et al, 2006;Spichak et al, 2007b;Spichak et al, 2013).…”

A New Conceptual Model of the Icelandic Crust: Hengill Case Study

“…Unlike the most popular approach to reducing of the so-called "static shift" effect by correcting the MT curves with TEM data measured in the same locations (see, for instance Árnason et al (2010)), Spichak et al (2013) used to this end all available TEM and MT data (not necessarily collected in the same sites). In this case, 1-D resistivity profiles determined from the TEM data were used up to the depth of 1 km while 1-D resistivity profiles determined from the MT data -from 1 to 3 km.…”

“…The second zone trends parallel to the Olkeduhals transverse tectonic structure (Figure 8.1) and deepens north-northeast from 12.5 to 17.5 km. Spichak et al, 2013). White dots indicate the earthquake hypocenters according to (Jousset et al, 2011).…”

“…Spichak et al (2013) provided the answers to the questions enumerated above based on (1) estimation of the 3-D temperature distribution in the Hengill geothermal area (Iceland) from the resistivity data up to the depth of 20 km, (2) identification of the heat sources of the geothermal system, and (3) analysis of the seismicity pattern. Spichak et al (2013) provided the answers to the questions enumerated above based on (1) estimation of the 3-D temperature distribution in the Hengill geothermal area (Iceland) from the resistivity data up to the depth of 20 km, (2) identification of the heat sources of the geothermal system, and (3) analysis of the seismicity pattern.…”

“…Dashed profiles indicate projections onto horizontal plane of the vertical temperature cross-sections shown in Figures 8.9-8.10 (redrawn after(Spichak et al, 2013)). Circles mark TEM sites, dots indicate MT sites, triangles mark boreholes (shaded ones mark boreholes used for EM geothermometer testing).…”