Plate boundary deformation and man-made subsidence around geothermal fields on the Reykjanes Peninsula, Iceland

Keiding, Marie; Árnadóttir, Þóra; Jónsson, Sigurjón; Decriem, J.; Hooper, Andrew

doi:10.1016/j.jvolgeores.2010.04.011

Cited by 60 publications

(43 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Adding together LOS changes from ascending and descending tracks results in a linear combination that is mostly dependent on the vertical displacement (see LOS unit vectors in Table 1), and subtracting them results in a linear combination mostly dependent on the east displacement component. These linear combinations can be scaled to reveal near‐vertical and near‐east displacement components [e.g., Keiding et al , ]. In our case (Figure ), this decomposition of coupled LOS changes shows the lava tongues selected as special target areas have a relatively well‐defined vertical displacement field.…”

Section: Discussionmentioning

confidence: 99%

Post‐emplacement cooling and contraction of lava flows: InSAR observations and a thermal model for lava fields at Hekla volcano, Iceland

et al. 2017

View full text Add to dashboard Cite

Lava flows contract as they cool, causing progressive subsidence of the flow surface. Here we study this process by measuring and modeling the deformation of emplaced lava flows and the surrounding substrate. The temporal trend of vertical lava movements was investigated using interferometric analysis of synthetic aperture radar (InSAR) images from the 1991 and 2000 Hekla eruptions, covering periods of 23 and 12 years, respectively. Data from six tracks from three satellites, including both ascending and descending passes, were used to create 99 interferograms, from which trends of accumulated subsidence and subsidence velocities were derived. Subsidence rates are similar for both lava flows and decay approximately exponentially from about 20 mm/yr 5 years after emplacement to about 2 mm/yr 15 years after emplacement. A one‐dimensional, semi‐analytical model was fitted to the observed subsidence rates, with subsidence due to phase change calculated analytically and subsidence due to thermal contraction calculated numerically using dilatometric constraints obtained experimentally. The initial thicknesses of the 1991 and 2000 lava fields, D1991 and D2000, scaled thermal expansivity, γα, and thermal diffusivity, κ, are the crucial parameters influencing lava subsidence and subsidence rate. Inversion for these parameters reveal linear correlations between them. Best fitting results of inversions for D1991 range from 10 m to 27 m, for D2000 from 10 m to 30 m, γα= 9–24 ×10−6 K−1, and κ= 1–7 ×10−7 m2 s−1.

show abstract

Section: Discussionmentioning

confidence: 99%

Post‐emplacement cooling and contraction of lava flows: InSAR observations and a thermal model for lava fields at Hekla volcano, Iceland

et al. 2017

View full text Add to dashboard Cite

show abstract

“…We compare the calculated surface deformation with the observed deformation from our GNSS and InSAR data sets and adjust the source parameters to obtain the best agreement with the data. Following previous studies of deformation in geothermal areas we assume a shear modulus of μ = 10 GPa and a Poisson's ratio of ν = 0.25 [see Fialko and Simons , ; Keiding et al , ].…”

Section: Inverse Modelingmentioning

confidence: 99%

Anthropogenic and natural ground deformation in the Hengill geothermal area, Iceland

et al. 2017

Self Cite

View full text Add to dashboard Cite

We investigate crustal deformation due to the extraction of water and steam from a high‐enthalpy geothermal reservoir; a common occurrence, yet not well understood. The cause of this deformation can be a change in pressure or in temperature in the reservoir, both of which can be caused by extraction or injection of geothermal fluids. Our study area, the Hengill mountains in SW Iceland, is an active volcanic center and a plate triple junction that hosts two power plants producing geothermal energy. This combination of natural and anthropogenic processes causes a complex displacement field at the surface. We analyze geodetic data—Global Navigation Satellite System and Interferometric Synthetic Aperture Radar—to obtain the surface velocity field, which we then simulate using an inverse modeling approach. We focus on the deformation around the geothermal power plants but need to model the regional tectonic and volcanic deformation as well, because the signals are overlapping. We find that plate motion and a deep contracting body can explain the broad scale signal in the area. Local deformation near the two power plants, Hellisheidi and Nesjavellir, can be explained by extraction of geothermal fluids. We estimate reservoirs extending from 0.6 to 3.0 km depth at Hellisheidi, and 1.0 to 3.0 km depth at Nesjavellir for observed pressure decrease rates of 0.25 MPa/yr and 0.1 MPa/yr, respectively. We find that the main cause for the subsidence in the geothermal area is the observed pressure drawdown.

show abstract

“…Subsidence is accentuated by compressible rock formations in the upper part or above a shallow reservoir, which is drained and compacted after pore pressure decline. They are more common for liquid dominated fields, which are often located in young unconsolidated volcanic rock [22,37]. For example, the subsidence rate at Wairakei geothermal field reached 45 cm/year, at Larderello (Italy) 25 cm/ year, and at Svartsengi (Iceland) 1 cm/year [18,38,39].…”

Section: Geological Hazardsmentioning

confidence: 99%

Review on life cycle environmental effects of geothermal power generation

Bayer

Rybach

Blum

et al. 2013

Renewable and Sustainable Energy Reviews

189

View full text Add to dashboard Cite

Plate boundary deformation and man-made subsidence around geothermal fields on the Reykjanes Peninsula, Iceland

Cited by 60 publications

References 39 publications

Post‐emplacement cooling and contraction of lava flows: InSAR observations and a thermal model for lava fields at Hekla volcano, Iceland

Post‐emplacement cooling and contraction of lava flows: InSAR observations and a thermal model for lava fields at Hekla volcano, Iceland

Anthropogenic and natural ground deformation in the Hengill geothermal area, Iceland

Review on life cycle environmental effects of geothermal power generation

Contact Info

Product

Resources

About