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Journal of Seismology

, 13:479 | Cite as

Broadband frequency-dependent amplification of seismic waves across Bucharest, Romania

  • Henriette SudhausEmail author
  • Joachim Ritter
Original article

Abstract

The determination of seismic amplitude amplification is a fundamental contribution to seismic hazard assessment. While often only high-frequency amplitude variations (>1 Hz) are taken into account, we analyse broadband waveforms from 0.14 to 8.6 Hz using a temporary network of 32 stations in and around the earthquake-prone city of Bucharest. Spectral amplitudes are calculated with an adaptive multiple-taper approach. Across our network (aperture 25 km × 25 km), we find a systematic northwest/southeast-oriented structural influence on teleseismic P-wave amplitudes from 0.14 to 0.86 Hz that can be explained by constructive interference in the dipping Cenozoic sedimentary layers. For higher frequencies (1.4–8.75 Hz), more local site effects prevail and can be correlated partly among neighbouring stations. The transition between systematic and localised amplitude variations occurs at about 1 Hz.

Keywords

Site effects Seismic amplification Frequency-dependent amplification Spectral ratios Multiple taper Bucharest Vrancea 

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Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.Institute of GeophysicsETH ZurichZurichSwitzerland
  2. 2.Geophysical InstituteUniversität Karlsruhe (TH)KarlsruheGermany

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