Scientific Reports (Sep 2017)

Near-source high-rate GPS, strong motion and InSAR observations to image the 2015 Lefkada (Greece) Earthquake rupture history

  • Antonio Avallone,
  • Antonella Cirella,
  • Daniele Cheloni,
  • Cristiano Tolomei,
  • Nikos Theodoulidis,
  • Alessio Piatanesi,
  • Pierre Briole,
  • Athanassios Ganas

DOI
https://doi.org/10.1038/s41598-017-10431-w
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 12

Abstract

Read online

Abstract The 2015/11/17 Lefkada (Greece) earthquake ruptured a segment of the Cephalonia Transform Fault (CTF) where probably the penultimate major event was in 1948. Using near-source strong motion and high sampling rate GPS data and Sentinel-1A SAR images on two tracks, we performed the inversion for the geometry, slip distribution and rupture history of the causative fault with a three-step self-consistent procedure, in which every step provided input parameters for the next one. Our preferred model results in a ~70° ESE-dipping and ~13° N-striking fault plane, with a strike-slip mechanism (rake ~169°) in agreement with the CTF tectonic regime. This model shows a bilateral propagation spanning ~9 s with the activation of three main slip patches, characterized by rise time and peak slip velocity in the ranges 2.5–3.5 s and 1.4–2.4 m/s, respectively, corresponding to 1.2–1.8 m of slip which is mainly concentrated in the shallower ( 6) earthquakes to the northern and to the southern boundaries of the 2015 causative fault cannot be excluded.