Since 2002, we have collected groundwater samples from a deep aquifer close to the Húsavík-Flatey Fault on northern Iceland. We were able to detect concentration anomalies for transition metals prior to an M 5.8 earthquake on September 16, 2002. This earthquake fractured a hydrological barrier permitting influx of groundwater from another aquifer. Following this earthquake, we have been able to monitor fracture healing, recorded by a hydrogeochemical recovery. This recovery process has been interrupted by several fracturing events since 2002. Mineralogical evidence from exhumed fault rocks suggests that fracture healing occurs by sequential precipitation of calcite, clays and zeolites and textural evidence confirms that oth re-fracturing and re-healing events have occurred.
Contact information
PIs
Alasdair Skelton | alasdair.skelton@geo.su.se
Niklas Wästeby
Helga Guðrúnardóttir
Lillemor Claesson Hrefna Kristmansdóttir
Publications
Claesson, L., Skelton, A., Graham, C. and Mörth, C-M., 2007. The timescale and mechanisms of fault sealing and water-rock interaction after an earthquake. Geofluids, 7, 427–440.
Claesson, L., Skelton, A.D.L., Graham, C.M., Dietl, C., Mörth, M., Torssander, P. and Kockum, I., 2004. Hydrogeochemical changes before and after a major earthquake. Geology., 32, 641–644.
