Satellite radar interferometry 1993–1999 suggests deep accumulation of magma near the crust‐mantle boundary at the Krafla volcanic system, Iceland

Abstract

Deep magma accumulation near the crust‐mantle boundary (21 km depth) at the Krafla volcanic system is suggested from InSAR observations. A best fit model, derived from four interferograms covering 1993–1999, comprises an opening dike, representing plate spreading and post‐rifting deformation, and two Mogi sources. A Mogi source deflating at a rate of ∼0.3 × 10 6 m 3 /yr coincides with the shallow Krafla magma chamber while a deeper inflating Mogi source, further north, at 21 km depth, inflates at a rate of ∼26 × 10 6 m 3 /yr. The inflating source is at or near the crust‐mantle boundary as identified by seismic studies and is interpreted as accumulating magma.