EGU2020-11801
https://doi.org/10.5194/egusphere-egu2020-11801
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Integrated microgravimetric and seismic monitoring approach in the Þeistareykir volcanic geothermal field (North Iceland).

Florian Schäfer1, Philippe Jousset1, Tania Toledo1, Andreas Güntner1, Tilo Schöne1, David Naranjo1,2, Kemal Erbas1, Egill Juliusson3, and Richard Warburton4
Florian Schäfer et al.
  • 1GFZ Potsdam, Potsdam, Germany (florian@gfz-potsdam.de; philippe.jousset@gfz-potsdam.de)
  • 2ETH Zürich, Switzerland
  • 3Landsvirkjun, Iceland
  • 4GWR Instruments, USA

In volcanic and hydrothermal systems, monitoring of mass and stress changes by continuous gravity field and ground motion records provides information for both volcanic hazard assessment and estimation of geothermal resources. We aim at a better understanding of volcanic and geothermal system processes by addressing mass changes in relation with external influences such as anthropogenic (reservoir exploitation) and natural forcing (local and regional earthquake activity, earth tides). Þeistareykir is a geothermal field located within the Northern Volcanic Zone (NVZ) of Iceland on the Mid-Atlantic Ridge. Geothermal power production started in autumn 2017. For the first time on a geothermal production field, we deployed a network of 4 continuously recording gravity meters (3 superconducting meter, iGrav and one spring gravity meter gPhone) in order to cover the spatial and the temporal changes of gravity and to detect small variations related to the geothermal power plant operation (e.g. extraction and injection). All gravity monitoring stations are equipped with additional instrumentation to measure parameters that may affect the gravity records (e.g. GNSS and hydrometeorological sensors). Additionally, we deployed a temporal seismic network consisting of 14 broadband stations to enhance the seismic activity monitoring of the permanent Icelandic network in this very active region of the NVZ. Results of this unique experiment contribute to determine reservoir properties and main structures and may also reveal details of active tectonic processes. Here, we present the instrumental setup at the site and first results of more than 24 months of continuous gravity and seismicity records.

How to cite: Schäfer, F., Jousset, P., Toledo, T., Güntner, A., Schöne, T., Naranjo, D., Erbas, K., Juliusson, E., and Warburton, R.: Integrated microgravimetric and seismic monitoring approach in the Þeistareykir volcanic geothermal field (North Iceland). , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11801, https://doi.org/10.5194/egusphere-egu2020-11801, 2020

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