| Title | Existence and nature of low-temperature geothermal systems in Eyjafjördur, N-Iceland, from a geophysical perspective |
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| Authors | Egill Árni Gudnason, Thorbjörg Ágústsdóttir, Rögnvaldur Líndal Magnússon, Gudni Axelsson, Ólafur G |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Geothermal utilisation in Iceland involves the exploitation of both low- and high-temperature resources for electricity generation as well as space heating and other direct uses. In Eyjafjördur, N-Iceland, the basaltic crust hosts low-temperature geothermal systems of which some have been harvested for half a century, while others have been discovered more recently. In this area, the basaltic crust is comprised of lava flows with thin sedimentary horizons, with the stratigraphic pile crosscut by basaltic dikes. Its permeability is almost entirely tied to vertical and sub-vertical faults and fractures, with the main heat source of these low-temperature geothermal resources being the background heat flow in Iceland. We examine the existence and nature of the low-temperature geothermal systems in western Eyjafjördur, from the island of Hrísey in the north to Hjalteyri in the south. The analysis is mainly based on monitoring and evaluation of micro-seismicity in the area, using data from a local seismic network operated by Iceland GeoSurvey for the local utility service, Nordurorka, since 2017. The focus is on exploring how seismicity and active tectonics enhance permeability in the basaltic crust. We also consider results from resistivity surveys, magnetic measurements and well logs for an improved understanding and updated conceptual model of these low-temperature geothermal systems. |