Hydrothermal fluid flow triggered by an earthquake in Iceland

• Published in: Communications earth & environment Vol. 3; no. 1; pp. 1 - 9
• Main Authors: Geoffroy, Laurent, Dorbath, Catherine, Ágústsson, Kristján, Kristjánsdóttir, Sigríður, Flóvenz, Ólafur G., Doubre, Cécile, Gudmundsson, Ólafur, Barreyre, Thibaut, Bazin, Sara, Franco, Aurore
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 01.12.2022; Springer Nature; Nature Portfolio
• Subjects: Earthquakes; Fluid dynamics; Fluid flow; Fractures; Heat transmission; High temperature; Permeability; Pore pressure; Pore water pressure; Sciences of the Universe; Seismic activity; Seismic surveys; Seismicity; Tectonics; Iceland
• ISSN: 2662-4435; 2662-4435
• DOI: 10.1038/s43247-022-00382-0

Abstract Microearthquake hypocenters were analyzed in the Krýsuvík geothermal area in SW-Iceland with data taken from two consecutive passive seismic surveys, 2005 and 2009. Five years prior to the 2005 survey, this area was struck by an earthquake initiating a major top-to-bottom fluid migration in the upper crust. We observe from our surveys a complex bottom-to-top migration of seismicity with time following this fluid penetration, suggesting the migration of a pore pressure front controlled by the upper-crust fracture system. We interpret these data as the time and space development of high-temperature hydrothermal cells from a deep upper crustal fluid reservoir in the supercritical field. These results provide an insight into the coupling mechanisms between active tectonics and fluid flow in upper-crustal extensional systems with high thermal flux.