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| Titel |
High-frequency ground motion scaling in the Gulf of Corinth (Greece) |
| VerfasserIn |
Christos P. Evangelidis, Sebastiano D'Amico, Nikolaos S. Melis |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250095705
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| Publikation (Nr.) |
 EGU/EGU2014-11173.pdf |
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| Zusammenfassung |
| The evaluation of the expected peak ground motion caused by an earthquake is of great
importance in seismicity and earthquake engineering studies. In the present study,
weak-motion data related to small earthquakes are used, in order to extrapolate peak ground
motion parameters beyond the magnitude range of the weak-motion dataset, on which they
are calculated. A complete description of the seismic ground-motion characteristics in the
Gulf of Corinth region in Greece is provided, with parameterization of the attenuation of
seismic ground motions with distance and their variability in excitation with earthquake
magnitude.
We use over 1000 earthquakes recorded at the Hellenic Unified Seismic Network (HUSN)
with magnitudes larger than 2.5ML. Following a regression analysis of this large number of
weak-motion data, we determine a frequency-dependent crustal quality factor, a geometrical
spreading function and the absolute source scaling. In order to calibrate sufficiently the
source scaling, it is necessary to use the available moment magnitude values of events from
the selected dataset. The National Observatory of Athens Moment Tensor Database
(NOA-MTs) is used, which includes 52 events in the range 3.3 to 5.4MW for the time
period in analysis. Complementary, we calculate moment tensor solutions with high-quality
for small events not included in the NOA-MTs catalogue, using the “Cut And Paste”
technique.
Results on region-specific crustal attenuation and source scaling, together with the effective
duration of seismic ground motion in the region, are used to estimate the peak ground motion
parameters, such as PGA, PGV, and SA at different frequencies. Using stochastic
ground motion simulations, we predict the absolute level of ground shaking and
compare them with strong motion data in the region. The attenuation of simulated
ground motion is compared with recent global and regional ground motion prediction
equations (GMPEs). The performance of the stochastic model is also tested against
moderate sized earthquakes (~5-6MW) recorded by HUSN in the area under study. |
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