Overview of results from continuous GPS observations in Iceland from 1995 to 2010

Halldór Geirsson, Thóra Árnadóttir, Sigrún Hreinsdóttir, Judicael Decriem, Peter C. Lafemina, Sigurjón Jónsson, Richard A.bennett, Sabrina Metzger, Austin Holland, Erik Sturkell, Thierry Villemin, Christof Völksen, Freysteinn Sigmundsson, Páll Einarsson, Matthew J. Roberts, Hjörleifur Sveinbjörnsson

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

— Iceland is a natural laboratory for a variety of processes associated with crustal deformation, such as earthquakes, magmatic events, tectonic plate motions, and glacial load changes. Continuous GPS (CGPS) measurements started in Iceland in 1995, and since then data from the network have helped to shed light on many different active deformation processes. The number of CGPS sites in Iceland tripled during 2006–2008, as a result of an international collaborative effort coordinated by Icelandic scientists. By early 2010 the number of CGPS stations in Iceland had reached 64, located primarily around and within the North-American–Eurasian plate boundary zone. Since its initiation, the CGPS network has played an important role in monitoring volcanoes and seismogenic areas, most notably during the 2009–2010 Eyjafjallajökull volcano unrest. Plate spreading of up to 2 cm per year usually dominates the horizontal motion observed at the CGPS sites, while uplift is observed at many of the stations due to recent retreat of the Icelandic ice caps. Co-seismic and post-seismic deformation of the largest earthquakes in 2000 and 2008 in the South Iceland Seismic Zone were captured by the network, and high-rate (1 Hz) CGPS observations helped to identify two magnitude 6 mainshocks in 2008 that were separated in time by only 2–3 seconds. The CGPS network has thus enabled us to monitor deformation occurring over days to months caused by migration of magma or fluids, post-seismic transients, rapid deformation caused by earthquakes and eruptions, as well as the long term plate spreading signal.

Original languageEnglish (US)
Pages (from-to)3-22
Number of pages20
JournalJokull
Volume2010
Issue number60
StatePublished - 2010

Bibliographical note

Funding Information:
Most of the network expansion during 2006–2009 resulted from a joint effort of several research groups in Iceland, the United States and Switzerland. The projects are funded by the Icelandic Research Council, the US National Science Foundation (NSF), ETH Zurich, University of Arizona, and The Pennsylvania State University. The new CGPS stations form sub-networks (Figure 1) that have been installed in co-operation with the IMO, who operate a large part of the CGPS sites in Iceland. The network operated by IMO is called the ISGPS (Icelandic GPS) network. The sub-networks are: (1) The North Iceland network, with 10 CGPS stations installed by the group from ETH Zurich; (2) The Central Highland of Iceland (CHIL) network, with 14 stations installed by the group from the University of Arizona; (3) The Hekla network with 6 stations installed by the groups from The Pennsylvania State University and the Nordic Volcanological Center; (4) The South Iceland Seismic Zone and Reykjanes peninsula networks with 5 new stations installed by the groups from the Nordic Volcanological Center and University of Arizona.

Funding Information:
We acknowledge grants from the Icelandic Research Council (Grant of Excellence, and several project and equipment grants), NSF (EAR grant numbers 0711446 and 0711456), ETH Zurich research grant, and the EU funded project VOLUME. Additional funding was provided by University of Arizona, The Pennsylvania State University, and the Icelandic Meteorological Office. We wish to thank deeply all the numerous people involved in installing and running the CGPS network in Iceland. We thank reviewers Magnús Tumi Guðmundsson and Bradford Hager for their constructive comments. The figures were produced using the GMT public domain software (Wessel and Smith, 1998).

Publisher Copyright:
© 2010, Iceland Glaciological Society. All rights reserved.

ASJC Scopus subject areas

  • General Earth and Planetary Sciences

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