Resistivity survey of Grímsvötn

(2009-2012)
3 participants: ÍSOR, University of Iceland, HS-orka and GNS – New Zealand.
Supported by GEORG, GEOthermal Research Group:
http://www.georg.hi.is/node/152
Coordinator at ÍSOR: Knútur Árnason

The main objectives of a LOTEM survey of Grímsvötn are:

  • To map the spatial extent and depth span of resistivity anomalies in the upper crust under Grímvötn, allowing comparison with other high-temperature geothermal areas.
  • Map the location and extent of magma bodies in the uppermost 3-5 km of the crust under the volcano.
  • Use the data and comparisons with other areas to assess the reasons why a pristine geothermal area has heat release similar to that of a large thermal area under full exploitation (e.g. Nesjavellir, Hengill, Krafla).

The project is planned for three years. In the first year the PhD student will study electromagnetic methods in geothermal exploration. He will also carry out model calculations to optimize the survey setup to ensure sufficient depth of exploration and resolution. Two three weeks long field missions for data collection are planned in conjunction with the annual missions of the Icelandic Glaciological Society.After the first field mission, a processing sequence will be set up and inversion. From the results, the field strategy will be further developed for the second mission. After the second mission all collected data will be processed and inverted. Finally the resulting 3D resistivity model and other data (gravity and seismic data) will be interpreted jointly to build a conceptual model of the Grímsvötn volcano and its high-temperature geothermal system.


 

Contact:
Knútur Árnason
Chief Geophysicist

+354 528 1560
+354 893 8335
ka@isor.is