Variation of seismic activity andb-value in the wadati-benioff zone of the hellenic arc

Summary The statistics of the vertical distribution of earthquake foci belonging to the Wadati-Benioff zone in the Hellenic arc show that the seismic activity, in terms of the total number of events at a given depth range during the period 1901–82, and b value of the frequency-magnitude relation vary with depth in a specific manner. The seismic activity of the western and eastern flanks of the Wadati-Benioff zone varies with depth in a similar way, whereas the b-value depth variation for these two flanks of the subduction zone does not show such a similarity.