Crustal deformation studies in the seismically active area of Patras Gulf (GREECE)

A ten-station GPS network extending in the broader area of Patras Gulf was established in 1994 to study the local and regional ground deformation of the area. The network has been fully occupied in three periods: August 1994, October 1996 and January 2006. A smaller scale GPS network being consisted of seven stations was installed in July 2008 across the Rio-Antirrio strait (eastern part of Patras Gulf) and was remeasured in March 2009. Differential GPS data analysis of both networks was performed revealing an extension of Patras Gulf at a rate of ~10 mm/yr. Uplift of the southern part with respect to the subsided northern part of the gulf was observed. A continuously recording GPS station (at a frequency of 1 Hz) has been operating at Riolos (RLSO) since August 2006. Automatic data processing applying the Bernese Processing Engine (v.5.0) resulted in the estimation of its horizontal and vertical deformation through the period 2006-2011, in which the co-seismic effect of the 2008 Andravida Earthquake (M_w = 6.4) is evident.