Western Greece is a key area for understanding the tectonic processes in the Africa- Eurasia collision zone. Recent work by Serpelloni et al., (2005) indicates NE-SW compression between Apulia (Italy) and north-western Greece based on GPS measurements carried out between 1991 and 2002. In addition, McClusky et al., (2000) found that the central, and southern Aegean is characterized by coherent motion (internal deformation of <2 mm/yr) toward the SW at 30 +/- 1 mm/yr relative to Eurasia. Thus, western Greece is characterized by a strain field contrast between shortening (west) and extension (east). Relative plate motion to the west of the Ionian Islands is accommodated by dextral motion along the Cephalonia transform fault (Louvari et al., 1999) whose slip rate is 20 mm/yr (Serpelloni et al., (2005).

NOA has obtained funding for GPS observations through the EU project PREVIEW (www.preview-risk.com) and from National Research Programmes (PEP Ionian Sea - PEP Aegean Sea). The aim is to investigate the contemporary motions of the Western Greece over the time span of five years (2006·2010). One continuous GPS station comprising a Leica 1200GRXPro receiver has been installed in the island of Cephalonia (station VLS) on 12 February 2006. During 2007, three more receivers were installed on Lefkada and Corfu, respectively. Our objective is to get results on time series, trajectories and velocities of crustal motion, as well as a geodetic strain rate field. The current plan is to download 1-second sampled data (1 Hz) through the NOA telecom infrastructure on a daily basis, although we also collect data sampled 5 times per second (5 Hz) in a rotating buffer in these receivers, and to retrieve the high rate data after a large earthquake to support GPS seismology. The high rate (1 Hz · one sample per second) operations are also useful for the purpose of seismic early warning, damage mitigation, and to increase sensitivity to transient motions.

The master station is NOA1 which is located in mountain Pendeli, Athens. The station operates since 2006 and is part of the EUREF network. During 2007 NOA installed three GPS+GLONASS receivers on the islands of Lemnos (LEMN), Lesvos (PRKV) and in the town of Kato Nevrokopi, eastern Macedonia (NVRK). In May 2008 one station (KLOK) was installed at the MEDNET station THL (village Klokotos, Thessaly). This station is equipped with a choke ring antenna provided by INGV. In March 2009 another station (ATAL) was installed in the town hall of the town of Atalanti, in collaboration with the Higher Geodesy Laboratory of NTUA.

Station Coordinates and Standard Errors in ITRF 2005 (m)

Station Velocities with respect to stable Europe (m/yr)

Data Access

Links to 30-s RINEX daily data from the NOA GPS network can be found in the left column of this page.

NOA supports an Open Data Policy. Data are provided to the Science community under the agreement that proper acknowledgements are made.

Louvari E, Kiratzi AA, Papazachos BC, 1999. The Cephalonia Transform Fault and its extension to western Lefkada Island (Greece). Tectonophysics, 308 (1-2): 223-236.

McClusky S, Balassanian S, Barka A, Demir C, Ergintav S, Georgiev I, Gurkan O, Hamburger M, Hurst K, Kahle H, Kastens K, Kekelidze G, King R, Kotzev V, Lenk O, Mahmoud S, Mishin A, Nadariya M, Ouzounis A, Paradissis D, Peter Y, Prilepin M, Reilinger R, Sanli I, Seeger H, Tealeb A, Toksoz MN, Veis G. 2000. Global Positioning System constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus. Journal of Geophysical Research-Solid Earth, 105 B3): 5695-5719.

Serpelloni, E., Anzidei, M., Baldi, P., Casula, G., Galvani, A., 2005. Crustal Velocity and strain-rate fields in Italy and surrounding regions: new results from the analysis of permanent and non-permanent GPS networks. Geophys. J. Int., 161, 861-880.