Seismic imaging of the shallow crust beneath the Krafla central volcano, NE Iceland

• DOI: 10.1002/2015jb012350
• Publication Date: 2015-10-10T11:48:50Z
• Authors: Juerg Schuler; Tim Greenfield; Robert S. White; Steven W. Roecker; Bryndís Brandsdóttir; Joann M. Stock; Jon Tarasewicz; Hilary R. Martens; David Pugh
• Keywords: Caldera; Felsic; Magma chamber; Seismic Tomography; Epicenter

Abstract We studied the seismic velocity structure beneath Krafla central volcano, NE Iceland, by performing 3‐D tomographic inversions of 1453 earthquakes recorded a temporary local network between 2009 and 2012. The seismicity is concentrated primarily around Leirhnjúkur geothermal field near center caldera. To obtain robust models, we incorporated active data from previous surveys. volcano has relatively complex with higher P wave velocities ( V p ) underneath regions topographic relief two distinct low‐ anomalies field. latter match well attenuating bodies inferred S shadows during rifting episode 1974–1985. Within geothermalreservoir, resolved shallow (−0.5 to 0.5 km below sea level; bsl) region / s values deeper (0.5–1.5 high‐ zone. interpret difference in ratios zones be caused rock porosities crack densities lower region. A strong anomaly underlies these zones, where superheated steam zone within felsic overlies rhyolitic melt.