Short-Term Foreshocks as Key Information for Mainshock Timing and Rupture: The M_w6.8 25 October 2018 Zakynthos Earthquake, Hellenic Subduction Zone.

ABSTRACT: Significant seismicity anomalies preceded the 25 October 2018 mainshock (M_w = 6.8), NW Hellenic Arc: a transient intermediate-term (~2 yrs) swarm and a short-term (last 6 months) cluster with typical time-size-space foreshock patterns: activity increase, b-value drop, foreshocks move towards mainshock epicenter. The anomalies were identified with both a standard earthquake catalogue and a catalogue relocated with the Non-Linear Location (NLLoc) algorithm. Teleseismic P-waveforms inversion showed oblique-slip rupture with strike 10°, dip 24°, length ~70 km, faulting depth ~24 km, velocity 3.2 km/s, duration 18 s, slip 1.8 m within the asperity, seismic moment 2.0 × 10²⁶ dyne*cm. The two largest imminent foreshocks (M_w = 4.1, M_w = 4.8) occurred ver

SUBMITTER: Papadopoulos GA 

PROVIDER: S-EPMC7583035 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature