The 24 May 2014 (Mw6.8) earthquake (North Aegean Trough): spatiotemporal evolution, source and slip model from teleseismic data

Publication date: Available online 28 August 2016 Source:Physics and Chemistry of the Earth, Parts A/B/C Author(s): Anastasia Kiratzi, Eva Tsakiroudi, Christoforos Benetatos, George Karakaisis We use teleseismic data to calculate the source model of the 24 May 2014 earthquake and regional catalogues to examine the spatial-temporal characteristics of the sequence. The sequence started in Saros Basin but almost simultaneously aftershocks spread along a ∼200 km zone, activating the entire North Aegean Trough. The aftershock sequence was rich in moderate (M<4) size events, but very deficient in strong events – only two Mw4.9 aftershocks-a characteristic observed in previous sequences in the region. The teleseismic waveforms were best fit by two sub-events, which were lagged by 18s in time and by a 50 km jump in space, along the same fault line. The centroid depth of the first sub-event is 22km, at the base of the lower crust, and for the second is 14 km. The resolved total source time function is ∼30s. The finite-fault slip model is characterized by an asymmetric bilateral rupture propagation, to the west and east of the hypocentre. The major slip is confined downdip from the hypocentre, within the deeper 12-25km part. This deep slip migrated updip from the hypocentre to form the second slip patch, in the eastward segment. In all our models the maximum dislocation was of the order of 1m. For our preferred model parametrization, the rupture speed is 3km/s, and t...

Source: Physics and Chemistry of the Earth, Parts ABC - August 28, 2016 Category: Science Source Type: research