First Results of the 2005 Seismology – Geodesy Monitoring Campaign for Volcanic Crustal Deformation in the Reykjanes Peninsula, Iceland

Abstract

The Reykjanes Peninsula, Iceland, presents en-echelon volcano-tectonic systems trending oblique to the normal to the NAM-EUR separation. To better understand the tectonic of the Reykjanes Peninsula’s oblique spreading, a combined geodetic/seismologic campaign was performed from April to August 2005. For the seismologic part, 18 3-component seismometers of short period (1, 2 Hz) were deployed in an area of 30 km E–Wx20 km N–S. To detect small tectonic displacements less than 1 mm across postulated active faults, we used classical topometric measurements instead of GPS measurements, with high precision instrumentation: tacheometer, corner cube retro-reflectors, and centering system with hydraulic locking. The geodetic measurements were performed on 4 local networks in the studied area, on both sides of the fractures with points of about 10–100 m apart. In this contribution, we focus on the geodetic part of the campaign. We first present the geodetic networks and the reference frame setting used. Then, we describe the processing strategy, and show first results of the observed crustal deformations and time series analysis. Finally, a first comparison with the seismologic results is given.