EGU23-6864, updated on 25 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Developing Joint Geophysical and Petrological Inversion to Determine Temperature and Image the Lithosphere and Asthenosphere: De-risking Ireland's Geothermal Potential (DIG)

Emma Chambers1, Yihe Xu1,2, Raffaele Bonadio1, Javier Fullea1,3, Sergei Lebedev1,2, Duygu Kiyan1, Brian O'Reilly1, Patrick Meere4, Meysam Rezaeifar1, Tao Ye1, Aisling Scully4, Gaurav Tomar1, and the DIG Team*
Emma Chambers et al.
  • 1Dublin Institute for Advanced Studies, Cosmic Physics, Dublin, Ireland (
  • 2University of Cambridge, , Department of Earth Science, Cambridge, UK
  • 3Universidad Complutense de Madrid, Department of Physics of the Earth and Astrophysics, Madrid, Spain
  • 4University College Cork, School of Biological, Earth & Environmental Sciences, Cork, Ireland
  • *A full list of authors appears at the end of the abstract

High-quality maps of the geothermal gradient and temperature are essential when assessing the geothermal potential of a region. However, determining geothermal potential is a challenge as direct measurements of in situ temperature are sparse and individual geophysical methods are sensitive to a range of parameters, not solely temperature. Here, we develop a novel approach to determine the geothermal gradient using a joint geophysical-petrological inversion which requires thermal property data, seismic and additional geophysical datasets. The seismic data provide new constraints on lithospheric boundaries which influence crustal geotherms. We utilise large seismic datasets and extract Rayleigh- and Love-wave phase velocity dispersion curves, measured for pairs of stations. The measurements were performed using two methods with complementary period ranges; cross-correlation of teleseismic earthquakes and waveform inversion, yielding measurements in a broad period range (4-500 s).

The joint analysis of Rayleigh and Love measurements constrains the isotropic-average shear-wave velocity, relatable to temperature and composition providing essential constraints on the thermal structure of a region's lithosphere. We demonstrate this by inverting the data using an integrated joint geophysical-petrological thermodynamically self-consistent approach (Fullea et al., GJI 2021), where seismic velocities, electrical conductivity, and density are dependent on mineralogy, temperature, composition, water content, and the presence of melt. The multi-parameter models produced by the integrated inversions fit the surface-wave and other data and reveal the temperatures and geothermal gradients within the crust and mantle which will be used for future geothermal exploration and utilisation.

We use Ireland as a case study (part of the De-risking Ireland's Geothermal Potential project - DIG) and find that our new methodology produces results comparable to past temperature and geophysical measures, and enhances resolution. Lithospheric and crustal thickness play a key control on the temperature gradient with areas of thinner lithosphere resulting in elevated geotherms. In some locations we observe geotherms elevated beyond expectations which result from high radiogenic heat production from granitic rocks. This new methodology provides a robust workflow for determining the geothermal potential in areas with limited direct measurements.

The DIG project is funded by the Sustainable Energy Authority of Ireland under the SEAI Research, Development & Demonstration Funding Programme 2019 (grant number 19/RDD/522) and by the Geological Survey of Ireland.

DIG Team:

*: The listed authors of this abstract and: Colin Hogg - Dublin Institute for Advanced Studies, Ireland, Stephen Daly - University College Dublin, Ireland, Ben Mather - University of Sydney, Australia, Huda Mohamed - Dublin Institute for Advanced Studies, Ireland, Mark Muller - Geophysical Consultant, UK, Riccardo Pasquali - Geothermal Association of Ireland, Nicola Piana-Agostinetti - University of Milano-Bicocca, Italy, Jan Vozar - Earth Science Institute of the Slovak Academy of Sciences, Slovakia, John Weatherill - University College Cork, Ireland

How to cite: Chambers, E., Xu, Y., Bonadio, R., Fullea, J., Lebedev, S., Kiyan, D., O'Reilly, B., Meere, P., Rezaeifar, M., Ye, T., Scully, A., and Tomar, G. and the DIG Team: Developing Joint Geophysical and Petrological Inversion to Determine Temperature and Image the Lithosphere and Asthenosphere: De-risking Ireland's Geothermal Potential (DIG), EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6864,, 2023.