A Ground-Motion Prediction Model for Shallow Crustal Earthquakes in Greece

Abstract

Using a recently completed database of uniformly processed strong-motion data recorded in Greece, we derive a ground-motion prediction model (GMPM) for horizontal-component peak ground velocity, peak ground acceleration, and 5% damped pseudoacceleration response spectra, at 105 periods ranging from 0.01 to 10 s. The equations were developed by modifying a global GMPM, to account for more rapid attenuation and weaker magnitude scaling in the Greek ground motions than in the global GMPM. Our GMPM is calibrated using the Greek data for distances up to 300 km, magnitudes from 4.0 to 7.0, and time-averaged 30 m shear-wave velocities from 150 to 1200 m/s. The GMPM has important attributes for hazard applications including magnitude scaling that extends the range of applicability to M 8.0 and nonlinear site response. These features are possible because they are well constrained by data in the global GMPM from which our model is derived. An interesting feature of the Greek data, also observed previously in studies of mid-magnitude events (6.1–6.5) in Italy, is that they are substantially overpredicted by the global GMPM, which may be a repeatable regional feature, but may also be influenced by soil–structure interaction. This bias is an important source of epistemic uncertainty that should be considered in hazard analysis.

Seismic Risk Assessment of Chania, Greece, Using an Integrated Computational Approach

“…Furthermore, it seems that the attenuation of seismic waves is higher for earthquakes occurring inthe south of the Chania Prefecture, similar to the one in Gavdos, 2012 (eventhough Gavdos's earthquake was closer to Chania than the earthquake of Kythira). This is also verified by seismological (horizontal PGAs) data and available laws (i.e., Ground Motion Prediction Equations (GMPE)), e.g., Skarlatoudis et al [54] and Boore et al [55].…”

The 30 October 2020, MW = 7.0, Samos earthquake: aftershock relocation, slip model, Coulomb stress evolution and estimation of shaking

“…The above trend is also evident in static maps of macroseismic intensity (MMI), peak ground acceleration (PGA), peak ground velocity (PGV) and pseudo-spectral acceleration (PSA) at 0.3 s, 1.0 s and 3.0 s periods, which are shown in Figures S4-S9 in the Supplementary material. Diagrams of the fitted Ground Motion model (Boore et al, 2020) also demonstrate excellent fit to PGA, PGV and PSA from strong motion data, whilst converted values from testimonies are somewhat explained by the model (see Figures S10-S12 in the Supplementary material).…”

“…Site effects were taken into account using the V s 30 gridded layer produced by Stewart et al (2014) and made available at the USGS ShakeMap repository and github (https://usgs. maps.arcgis.com/apps/webappviewer/index.html?id=8ac19bc334f747e486550f32837578e1, https://github.com/usgs/earthquake-global_vs30/tree/master/Greece), combined with the Ground Motion Model (GMM) of Boore et al (2020). The location and dimensions of the fault plane were based on the slip model obtained in the current study using the technique presented in Section 4.2, which corresponds to the best fitting double-couple model from GCMT.…”

The 30 October 2020, Mw 7.0, Samos Earthquake: Aftershock Relocation, Slip Model, Coulomb Stress Evolution and Estimation of Shaking

“…The above trend is also evident in static maps of macroseismic intensity (MMI), peak ground acceleration (PGA), peak ground velocity (PGV) and pseudo-spectral acceleration (PSA) at 0.3 s, 1.0 s and 3.0 s periods, which are shown in Figures S4-S9 in the Supplementary material. Diagrams of the fitted Ground Motion model (Boore et al, 2020)…”