Slip Distribution of the 7 September 1999 Athens Earthquake Inferred from an Empirical Greens Function Study

The source process during the 7 September 1999 Athens (Greece) earthquake is investigated using broadband seismograms recorded at regional distances. Source time functions are estimated through an empirical Greenʹs function approach, and their shapes are inverted to reveal the spatial and temporal distribution of fault slip. The resulting slip-distribution pattern implies that about 50% of the total slip occurred at a depth greater than the hypocentral depth, indicating downward rupture propagation whereas 25% of the total slip was concentrated at a shallower patch. Forward calculations of the displacement field at the surface show that the shallower slip patch is possibly responsible for the asymmetry observed in the displacement field and it may have contributed significantly to the distribution of damage.