Characterization of sustainable geothermal and gas resources in the central Nepal Himalayan front

5 mois de février 2022 à juin 2022

Laboratoire d’accueil : ISTerre

Encadrants : Frédéric Donzé, ISTerre - Pascale Huyghe, ISTerre Retour ligne automatique
Frederic.donze univ-grenoble-alpes.frRetour ligne automatique
Pascale.huyghe univ-grenoble-alpes.fr

Key words : Nepal, Geothermal, Tectonic faults, Numerical modeling

Petroleum is the second largest energy fuel in Nepal after firewood and accounts for 8% of primary energy consumption in Nepal. All petroleum products are imported from India. Nepal is undergoing rapid economic and demographic development. Nepal’s energy scenario has not changed significantly during the decades ; this requires renewable energy (Ranjit, 2015).
In this project, we propose to study the geothermal system along the base of the High Himalaya, where numerous hot springs flow within and along the south-flowing streambeds. Geothermal systems in areas of relatively high regional heat flow often form along fault/fracture zones and are particularly prevalent where these fracture zones intersect with topographic lows (Evans et al., 2008 ; Rai et al., 2020). These geothermal sources are located near the city of near the city of Pokhara, whose population has increased from 43,000 to 439,000 inhabitants in 40 years.
These numerous hot springs can be enriched in economically strategic elements, such as lithium and native hydrogen (Monnin et al., 2021), but also problematic for health such as radon (Horvath et al., 2000). A multidisciplinary approach should be required to understand better the relationships between fluid compositions and the fault structure in an integrated perspective of consideration of seismic risks and possible geothermal resources.
Based on published data, this master project proposes to characterize and evaluate the resources associated with the hydrothermal system, based on numerical modeling. Indeed, the understanding of the dynamics of the fluids within the fault and of their physico-chemical properties (P, T, dissolved elements) is essential before considering their exploitation, in terms of geothermal energy and gas resources (H2, He).

Bibliography
Evans, M. J., Derry, L. A., & France‐Lanord, C. (2008). Degassing of metamorphic carbon dioxide from the Nepal Himalaya. Geochemistry, Geophysics, Geosystems, 9(4).
Horvath, A., Bohus, L. O., Urbani, F., Marx, G., Piroth, A., & Greaves, E. D. (2000). Radon concentrations in hot spring waters in northern Venezuela. Journal of environmental radioactivity, 47(2), 127-133.
Monnin, C., Quéméneur, M., Price, R., Jeanpert, J., Maurizot, P., Boulart, C., ... & Pelletier, B. (2021). The chemistry of hyperalkaline springs in serpentinizing environments : 1. the composition of free gases in New Caledonia compared to other springs worldwide. Journal of Geophysical Research : Biogeosciences.
Rai, S. M., Bhattarai, T. N., & Khatiwada, D. (2020). Hot Water Springs (Thermal Springs) in Nepal : A Review on Their Location, Origin, and Importance. Journal of Development Innovations, 4(2), 24-42.
Ranjit, M. (2015, April). Geothermal Energy Update of Nepal, Proceedings World Geothermal Congress 2015, Melbourne, Australia, 19-25 April 2015