Present-day crustal deformation field of the Iberian Peninsula estimated by GPS measurements

Abstract

We present the crustal deformation field in the Iberian Peninsula and northern Morocco, based on the analysis of the continuous GPS (CGPS) observations for the last five years, combined with the survey style observations (SGPS) of the CuaTeNeo network in eastern Betics. The analyzed CGPS stations come from several national and regional GNSS networks, with variable monument design and stability. Four CuaTeNeo campaigns were conducted with approximately a 4-year interval from 1997 to 2011. Although the calculated deformation field is complex, some expected features could be easily identified. Considering the Eurasia fixed frame, the highest velocities, as expected, are observed in Morocco, where the velocities reach 4.7±0.2 mm/yr. In southern Spain, stations located west of Almeria exhibit a westerly trend of motion, which reach 3.2±0.1 mm/yr at station SFER. The direction of these vectors makes us think that the main driving force behind the observed deformations cannot be solely attributed to the Africa-Eurasia convergence, but it should be due to the deeper geodynamic processes related to the subduction of the Betic-Alboran slab.