We calculate and analyse the coordinate time-series of 282 permanent GPS stations located in Greece and 47 in surrounding countries. The studied period is 2000–2020. The average GPS time-series length is 6.5 yr. The formal velocity uncertainties are rescaled to be consistent with the velocity scatters measured at 110 pairs of stations separated by less 15 km. We remove the effect of the crustal earthquakes of M_w ≥ 5.3. We quantify and model the post-seismic deformations. Two relaxation times are usually needed: one short of some weeks and one long of 1 yr or more. For the large M_w = 6.9 events of Samothraki 2014 and Methoni 2008, the post-seismic deformation equals or exceeds the coseismic one. We detect at three stations a deformation transient in May 2018 that may correspond to a slow earthquake beneath Zakynthos and northwest Peloponnese, with equivalent magnitude 5.8. The density and accuracy of the velocities make it possible to better quantify several characteristics of the deformation in the Aegean, in particular: (i) the transition from the Anatolian domain, located in the southeast, to the European domain through the western end of the North Anatolian fault; (ii) the north–south extension in the western Aegean; (iii) the east–west extension of the western Peloponnese; (iv) the clockwise rotation of the Pindos; (v) the north–south extension in central Macedonia. Large parts of the central Aegean, eastern Peloponnese and western Crete form a wide stable domain with internal deformation below 2 nstrain yr⁻¹. We build a kinematic model comprising 10 crustal blocks corresponding to areas where the velocities present homogeneous gradients. The blocks boundaries are set to fit with known localized deformation zones, for example, the rift of Corinth, the North Anatolian fault and the Katouna fault. When the velocity steps are clear but not localized, for example, through the Peloponnese, the boundary line is arbitrary and represents the transition zone. The model fits the velocities with a root-mean-square deviation of ±0.9 mm yr⁻¹. At the boundaries between blocks we compare the predicted and observed deformations. We find shear rates of 7.4 and 9.0 mm yr⁻¹ along the Movri and Katouna faults, 14.9 and 8.7 mm yr⁻¹ along the North Anatolian fault near Lemnos and near Skopelos respectively, extension of 7.6, 1.5 and 12.6 mm yr⁻¹ across the Gulf of Patras, the Trichonis Lake and the Ambracian Gulf. The compression across western Epirus is 3.7 mm yr⁻¹. There is a dextral transtensional movement of 4.5 mm yr⁻¹ between the Amorgos and Astypalea islands. Only the Ionian Islands region shows evidence of coupling along the subduction interface.

We investigate a seismic crisis that occurred in the western Gulf of Corinth (Greece) between December 2020 and February 2021. This area is the main focus of the Corinth Rift Laboratory (CRL) network, and has been closely monitored with local seismological and geodetic networks for 20 yr. The 2020–2021 seismic crisis evolved in three stages: It started with an $Mw$ 4.6 event near the northern shore of the Gulf, opposite of Aigion, then migrated eastward toward Trizonia Island after an $Mw$ 5.0 event, and eventually culminated with an $Mw$ 5.3 event, $∼3km$ northeast of the Psathopyrgos fault. Aftershocks gradually migrated westward, triggering another cluster near the junction with the Rion–Patras fault. Moment tensor inversion revealed mainly normal faulting; however, some strike‐slip mechanisms also exist, composing a complex tectonic regime in this region dominated by east–west normal faults. We employ seismic and geodetic observations to constrain the geometry and kinematics of the structures that hosted the major events. We discuss possible triggering mechanisms of the second and third stages of the sequence, including fluids migration and aseismic creep, and propose potential implications of the $Mw$ 5.3 mainshock for the seismic hazard of the region.

We identify the source of the M_w = 6.4 earthquake that rocked north-central Albania on November 26, 2019 02:54 UTC. We use synthetic aperture radar interferograms tied to the time series of coordinates of two permanent Global Navigation Satellite System (GNSS) stations (DUR2 and TIR2). We model the source by inverting the displacement data. Assuming in our model a half-space elastic medium and uniform slip along a rectangular fault surface, we invert the 104 picked measurements on a couple of ascending and descending interferograms to calculate the parameters of the fault. All inversions made with different input parameters converge towards a stable and robust solution with root mean square (r.m.s.) residual of 5.4 mm, thus ~1/5 of a fringe. They reveal that the earthquake occurred deep in the crust on a low-angle fault (23°) dipping towards east with a centroid at 16.5 km depth. The best-fitting length and width of the fault are 22 and 13 km, and the reverse slip, 0.55 m. The seismic moment deduced from our model agrees with those of the published seismic moment tensors. This geometry is compatible with a blind thrust fault that may root on the main basal thrust, i.e., along the thrust front that separates Adria–Apulia from Eurasia. It is notable that there is a 123 ns yr⁻¹ active shortening of the crust between the GNSS stations DUR2-TIR2 (equivalent to a shortening rate of 3.6 mm yr⁻¹), and roughly in the east–west direction. Given this amount of strain the recurrence time of M6+ earthquakes along this fault should be of the order of 150 years.