Hydrothermal fluid flow triggered by an earthquake in Iceland

• Published in: Communications Earth & Environment
• Main Authors: Geoffroy, Laurent, Dorbath, Catherine, Ágústsson, Kristján, Kristjánsdóttir, Sigrídur, Flóvenz, Ólafur G., Doubre, Cécile, Gudmundsson, Ólafur, Barreyre, Thibaut, Bazin, Sarah, Franco, Aurore
• Other Authors: Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Ecole et Observatoire des Sciences de la Terre (EOST), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDU]Sciences of the Universe [physics]; Krýsuvík; Iceland
• Online Access: https://insu.hal.science/insu-03684621; https://insu.hal.science/insu-03684621/document; https://insu.hal.science/insu-03684621/file/s43247-022-00382-0.pdf; https://doi.org/10.1038/s43247-022-00382-0

International audience 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.