Static stress changes along strike slip faults in Slovenia and Greece and seismic hazard implications

We examine the Coulomb (static) stress pattern following moderate magnitude earthquakes along strike-slip faults in NW Slovenia during 1998 and 2004 and several strong earthquakes in the North Aegean Sea (Greece). The objective is to investigate the seismic hazard implications for these areas given that future earthquakes may be triggered as a result of stress changes along neighbouring faults. Our findings include: a) stress levels have increased along the active Ravne fault (Slovenia) for all models discussed b) stress levels have decreased along the active, NW-SE striking Idria fault and c) stress levels throughout the crust have increased along the E-W direction but have decreased in the N-S direction (stress shadow effect). We also observe a pronounced stress shadow effect in the central Aegean Sea following two large earthquakes during December 1981 that terminated in July 2001 with a large (Mw=6.4) event near Skyros island. We also mapped a better correlation of the off-fault aftershock locations with stress maps incorporating the regional stress field.