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| Titel |
Fast long-period waves in near-regional records of a shallow earthquake |
| VerfasserIn |
Jiri Vackar, Jirí Zahradník |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250047830
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| Zusammenfassung |
| A recent shallow earthquake in the Corinth Gulf, Greece (Mw 5.3, January 18, 2010)
emphasized importance of unusual long-period waves (periods > 5 sec) observed at
near-regional seismic stations at the beginning of the records (starting already in the P-wave
group). The 5-sec period, being significantly longer than the source duration, indicates a
structural effect. Observed seismograms heve been examined by methods of the
frequency-time analysis. A special branch of the dispersion curve characterized by a
high group velocity has been found, suggesting likely an explanation in terms of
leaking modes, the PL waves. The structural effect has been also investigated by the
frequency-time analysis of synthetic seismograms. The aim was to recognize the
parameters with most significant effect on the occurrence of the fast long-period
waves such as the shallow earthquake depth, low-velocity crustal layers, layers
with a high vp-vs ratio. The sensitivity analysis indicated a way to use the specific
branches of dispersion curves for improving the existing regional crustal models. |
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