MICROSEIMICITY AND STRAIN PATTERN IN NORTHWESTERN GREECE

During a 7-week microearthquake experiment conducted in Epirus, Akarna nia, and the Ionian islands of western Greece, we located approximatel y 600 earthquakes with magnitudes between 2 and 4.2. No event was deep er than 40 km. The seismicity cannot be clearly associated with any si ngle fault except the Lixourion right-lateral fault located west of th e Ionian islands. Focal mechanisms of about 100 earthquakes show, for a narrow band of earthquakes located along the coast, ENE-WSW shorteni ng consistent with the surface tectonics. Farther east, focal mechanis ms show NNW-SSE extension beneath the foothills of the Pindus mountain s, which is unrelated to surface faulting but is consistent with the p resently subsiding basins. This strain pattern is seen far north and s outh of the Lixourion fault and is similar to the one observed in the Peloponnese. It suggests that a large-scale mechanism is responsible f or the recent geodynamics of both the northwestern and southwestern Ae gean