Abbreviations on map: RP, Reykjanes Peninsula Kl, Kleifarvatn H, Hengill volcano SISZ, south Iceland seismic zone He, Hekla volcano K, Katla volcano E, Eyjafjallajökull volcano T, Tjörnes Peninsula TFZ, Tjörnes fracture zone (outlined with black dashed lines) GL, Grímsey lineament HFF, Húsavík-Flatey fault, DL, Dalvík lineament. Stars note M > 5 earthquake epicenters on 17 and 21 June 2000. Continuous GPS stations are shown with black dots.
Dark gray areas are active fissure swarms, and light gray areas outline glaciers. The transform zones and offshore ridge segments are schematically drawn with black heavy lines. Arrows show velocity vectors predicted by the REVEL plate motion model, relative to stable North America. Schematic overview of the plate boundary in Iceland. The primary aims of the ISGPS network are to monitor crustal deformation processes in near real time and to contribute to better understanding of processes causing crustal deformation and natural hazards in Iceland. The first CGPS station in Iceland was installed in Reykjavík (REYK) in 1995 and presently there are 18 permanent GPS sites in Iceland, of which 14 belong to the ISGPS network ( Figure 1). Continuous GPS measurements (CGPS) provide enhanced temporal resolution and allow much improved estimation of station velocities, compared to campaign GPS. However, temporal resolution has been limited due to the intermittent nature of campaign GPS measurements. Previous studies have focused on parts of the plate boundary, allowing good spatial coverage of limited areas. Frequent GPS campaign measurements have been conducted since 1986, providing a wealth of information on plate movements, seismic, and volcanic processes. Various techniques have been used for this purpose in Iceland. The tectonic setting of Iceland on the divergent Mid-Atlantic Ridge, with frequent earthquakes and volcanic eruptions, makes it an ideal setting for studying crustal deformation. All stations with significant vertical velocities are moving up relative to the reference station REYK, with the highest velocity exceeding 20 mm/yr in the center of the island. The plate boundary deformation field has been locally and temporarily affected in south Iceland by two M w = 6.5 earthquakes in June 2000, inflation at Katla volcano during 2000 to 2004, and an eruption of Hekla volcano in February 2000. Of the two parallel branches of the plate boundary in south Iceland, the eastern volcanic zone is currently taking up the majority of the spreading and little is left for the western volcanic zone. Spreading is taken up within a ∼100–150 km wide plate boundary zone that runs through the island. The observed plate divergence between the North American and the Eurasian plates is in general agreement with existing models of plate motion.
We observe large-scale crustal deformation due to plate spreading across Iceland.
#MID ATLANTIC RIDGE PLATE BOUNDARY SOFTWARE#
We analyze data spanning up to 5 years from 18 continuous GPS stations in Iceland, computing daily positions of the stations with three different high-level geodetic processing software packages.
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