  In this paper, we present a first estimation, using the GIPSY-OASIS software,
of the crustal velocity and strain rate fields in the Balearic Islands (Spain),
based on continuous GPS observations from the XGAIB network spanning the period
2010-2013. The XGAIB network consists of nine permanent, widely distributed
stations that have operated continuously since 2010. In this paper, we describe
the XGAIB network and the CGPS data processing and present our principle
results in terms of the position time series and velocities of all of the
sites, which were observed for more than three and a half years. In addition,
strain tensors were estimated from the velocity field to obtain the first
realistic crustal deformation model of the archipelago. The strains exhibit
gradual variation across the Balearic Islands, from WNW-ESE extension in the
southwest (Ibiza and Formentera) to NW-SE compression in the northeast
(Menorca). These results constitute an advance in our knowledge of the
tectonics of the western Mediterranean region.
