The Samos Island (Aegean Sea) M7.0 earthquake: analysis and engineering implications of strong motion data


ASKAN GÜNDOĞAN A., GÜLERCE Z., Roumelioti Z., Sotiriadis D., Melis N. S. , Altindal A., ...More

BULLETIN OF EARTHQUAKE ENGINEERING, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2021
  • Doi Number: 10.1007/s10518-021-01251-5
  • Journal Name: BULLETIN OF EARTHQUAKE ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aquatic Science & Fisheries Abstracts (ASFA), Compendex, Geobase, INSPEC, Civil Engineering Abstracts
  • Keywords: Samos earthquake 2020, Strong motion, Macroseismic intensity, Ground motion models, AVERAGE HORIZONTAL COMPONENT, PEAK GROUND MOTION, NGA MODEL, PGV, TURKEY, ACCELERATION, INTENSITY
  • Middle East Technical University Affiliated: Yes

Abstract

We present a dataset of 77 strong ground motion records within 200 km epicentral distance from the 30 October 2020, M7.0 Samos Island (Aegean Sea) earthquake, which affected Greece and Turkey. Accelerograms from National Networks of both countries have been merged into a single dataset, including metadata that have been uniformly derived using a common preliminary source model. Initial findings from the analysis and comparative examination of acceleration time histories, Fourier amplitude spectra and 5%-damped response spectra are discussed along with significant source, propagation path and site effects. The long-period amplifications observed in most records in Izmir bay triggered failures and severe damages in weak structures. Yet, the spectral accelerations are observed to lie below the current and previous design spectra corresponding to the damaged regions. Peak ground motions are used to construct a purely instrumental-based macroseismic intensity map, which is capable of reflecting the actual earthquake damage caused by this considerably large event. Finally, peak ground motions are compared to various ground motion models (GMMs) and deviations are highlighted. Our overall preliminary analysis reveals a strong energy signature of the Samos earthquake in the period range 0.5-1.5 s at many sites, both on rock and soil, whereas records in the heavily hit Izmir city, at an epicentral distance circa 70 km, provide strong indication for additional amplification due to basin effects. At relatively large distance from the earthquake source (> 120 km), several recorded amplitudes are significantly lower than those predicted by many GMMs, implying that further studies are necessary toward the improvement of regional attenuation models.