Friday, March 24, 2017

Switzerland: The Origin of an Alpine Geothermal Resource

Steep rise of the Bernese Alps (Phys.Org)

View of the granite bastion north of Grimsel Lake with glacially polished granite surfaces being heavily dissected by morphological incisions. These furrows (see arrows) are all the result of steep fault zones, which originated at a depth of 20 kilometres. Due to uplift and erosion, they are recognisable today on the earth’s surface as couloirs in the topography. Credit: M. Herwegh, Institute for Geology, University of Bern
The striking north face of the Bernese Alps is the result of a steep rise of rocks from the depths following a collision of two tectonic plates. This steep rise gives new insight into the final stage of mountain building and provides important knowledge with regard to active natural hazards and geothermal energy. The results from researchers at the University of Bern and ETH Z├╝rich are being published in Scientific Reports.

The leakage of warm hydrothermal water, which it is important to explore for geothermal energy and the 2050 energy policy, can be traced directly back to the brittle fracturing of the upper earth's crust and the seeping in of cold surface waters. The water is heated up in the depths and arrives at the surface again through the steep fault zones – for example, in the Grimsel region. In this sense, the new findings lead to a deeper understanding of surface processes, which influence our infrastructures, for example the transit axes (rail, roads) through the Alps.

More information: Marco Herwegh et al. Large-Scale Crustal-Block-Extrusion During Late Alpine Collision, Scientific Reports (2017). DOI: 10.1038/s41598-017-00440-0

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