Joint Geophysical and Petrological Inversion to Image the Lithosphere and Asthenosphere Beneath Ireland and Britain
- 1School of Cosmic Physics, Dublin Institute for Advanced Studies, Dublin, Ireland (echambers@cp.dias.ie)
- 2Department of Earth Science, University of Cambridge, Cambridge, UK
- 3Department of Physics of the Earth and Astrophysics, Universidad Complutense de Madrid (UCM), Madrid, Spain
- 4School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- *A full list of authors appears at the end of the abstract
DIG (De-risking Ireland’s Geothermal Potential) integrates inter-disciplinary and multi-scale datasets in order to investigate Ireland’s low-enthalpy geothermal energy potential. Recent deployments of broadband seismic stations and the output surface-wave measurements yield dense data sampling of the crust and mantle beneath Ireland and neighbouring Great Britain, which can be used to determine the lithospheric and asthenospheric structure at a regional scale. In addition, we integrate magnetotelluric measurements, forming the foundations for a region-scale, multi-parameter modelling of the thermal and compositional structure of the lithosphere.
In this study, we utilise the large seismic dataset and extract Rayleigh and Love-wave phase velocity dispersion curves, measured for pairs of stations across Ireland and Great Britain. The measurements were performed using two methods with complementary period ranges; the teleseismic cross-correlation method and the waveform inversion method, yielding a 4-500 s period range for the dispersion curves. 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 the 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, revealing the temperatures and geothermal gradients within the crust and mantle, which will be used for future geothermal exploration and utilisation.
The 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.
The listed authors of this abstract and: Stephen Daly (University College Dublin, Ireland), Colin Hogg (Dublin Institute for Advanced Studies, 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., Bonadio, R., Lebedev, S., Fullea, J., Kiyan, D., Bean, C., O'Reilly, B., Meere, P., Rezaeifar, M., Tomar, G., and Ye, T. and the DIG Team: Joint Geophysical and Petrological Inversion to Image the Lithosphere and Asthenosphere Beneath Ireland and Britain, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3850, https://doi.org/10.5194/egusphere-egu22-3850, 2022.
