TY  - JOUR
A1  - Flóvenz, Ólafur G.
A1  - Wang, Rongjiang
A1  - Hersir, Gylfi Páll
A1  - Dahm, Torsten
A1  - Hainzl, Sebastian
A1  - Vassileva, Magdalena
A1  - Drouin, Vincent
A1  - Heimann, Sebastian
A1  - Isken, Marius Paul
A1  - Gudnason, Egill Á.
A1  - Ágústsson, Kristján
A1  - Ágústsdóttir, Thorbjörg
A1  - Horálek, Josef
A1  - Motagh, Mahdi
A1  - Walter, Thomas R.
A1  - Rivalta, Eleonora
A1  - Jousset, Philippe
A1  - Krawczyk, Charlotte M.
A1  - Milkereit, Claus
T1  - Cyclical geothermal unrest as a precursor to Iceland's 2021 Fagradalsfjall eruption
T2  - Nature geoscience
N2  - Understanding and constraining the source of geodetic deformation in volcanic areas is an important component of hazard assessment. Here, we analyse deformation and seismicity for one year before the March 2021 Fagradalsfjall eruption in Iceland. We generate a high-resolution catalogue of 39,500 earthquakes using optical cable recordings and develop a poroelastic model to describe three pre-eruptional uplift and subsidence cycles at the Svartsengi geothermal field, 8 km west of the eruption site. We find the observed deformation is best explained by cyclic intrusions into a permeable aquifer by a fluid injected at 4 km depth below the geothermal field, with a total volume of 0.11 ± 0.05 km3 and a density of 850 ± 350 kg m–3. We therefore suggest that ingression of magmatic CO2 can explain the geodetic, gravity and seismic data, although some contribution of magma cannot be excluded.
Y1  - 2022
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/64377
SN  - 1752-0894
SN  - 1752-0908
VL  - 15
IS  - 5
SP  - 397
EP  - 404
PB  - Nature Research
CY  - Berlin
ER  -