Crustal Deformation from 1992 to 1995 at the Mid-Atlantic Ridge,
Southwest Iceland, Mapped by Satellite Radar Interferometry
Hélène Vadon
and
Freysteinn Sigmundsson
Satellite radar interferometry observations of the Reykjanes
Peninsula oblique rift in southwest Iceland show that the Reykjanes central volcano subsided at an average rate of up to 13 millimeters per
year from 1992 to 1995 in response to use of its geothermal field.
Interferograms spanning up to 3.12 years also include signatures of
plate spreading and indicate that the plate boundary is locked at a
depth of about 5 kilometers. Below that depth, the plate movements are
accommodated by continuous ductile deformation, which is not fully
balanced by inflow of magma from depth, causing subsidence of the plate
boundary of about 6.5 millimeters per year.
H. Vadon, Centre National d'Études Spatiales, 18 Avenue
Edouard Belin, 31055, Toulouse, France.
F. Sigmundsson, Nordic Volcanological Institute, University of
Iceland, Grensasvegur 50, IS-108 Reykjavik, Iceland.
