Source Mechanisms and Stress Fields of the 15–16 June 2013 Crete Earthquake Sequence Along Hellenic Subduction Zone

Autor: Ethem Görgün
Rok vydání: 2016
Předmět:
Zdroj: Pure and Applied Geophysics. 174:1181-1199
ISSN: 1420-9136
0033-4553
Popis: 15 June 2013 M w 6.1 off-shore southern Crete earthquake and its aftershock sequence along Hellenic Subduction Zone are examined. Centroid moment tensors (CMTs) for 40 earthquakes with moment magnitudes (M w) between 3.5 and 6.1 are determined by applying a waveform inversion method. The mainshock is shallow focus thrust event with a minor strike-slip component at a depth of 20 km. The seismic moment (M o) of the mainshock is estimated as 2.07 × 1018 Nm, and rupture duration of the mainshock is 4 s. The focal mechanisms of aftershocks are mainly thrust faulting with a strike-slip component. The geometry of the moment tensors (M w ≥ 3.5) reveals a thrust faulting regime with N–S trending direction of P axis in the entire activated region. According to high-resolution CMT solutions of the off-shore southern Crete earthquake sequence, one main cluster consisting of 40 events is revealed. The aftershock activity in the observation period between 15 June and 15 July 2013 extends from N to S and NW to SE directions. Seismic cross sections indicate a complex pattern of the hypocenter distribution with the activation of two segments. The subduction interface is clearly revealed with high-resolution hypocenter source relocation and moment tensor solution. The best-constrained focal depths indicate that the aftershock sequence is mainly confined in the upper plate (depth
Databáze: OpenAIRE
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