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| Titel |
Crustal Seismic Attenuation in Germany Measured with Acoustic Radiative Transfer Theory |
| VerfasserIn |
Peter J. Gaebler, Tom Eulenfeld, Ulrich Wegler |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250143084
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| Publikation (Nr.) |
 EGU/EGU2017-6779.pdf |
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| Zusammenfassung |
| This work is carried out in the context of the Comprehensive Nuclear-Test-Ban
Treaty (CTBT). As part of this treaty a verification regime was introduced to detect,
locate and characterize nuclear explosion testings. The study of seismology can
provide essential information in the form of broadband waveform recordings for the
identification and verification of these critical events. A profound knowledge of the
Earth’s subsurface between source and receiver is required for a detailed description
of the seismic wave field. In addition to underground parameters such as seismic
velocity or anisotropy, information about seismic attenuation values of the medium are
required.
Goal of this study is the creation of a comprehensive model of crustal seismic attenuation in
Germany and adjacent areas. Over 20 years of earthquake data from the German Central
Seismological Observatory data archive is used to estimate the spatial dependent distribution
of seismic intrinsic and scattering attenuation of S-waves for frequencies between 0.5 and 20
Hz. The attenuation models are estimated by fitting synthetic seismogram envelopes
calculated with acoustic radiative transfer theory to observed seismogram envelopes. This
theory describes the propagation of seismic S-energy under the assumption of multiple
isotropic scattering, the crustal structure of the scattering medium is hereby represented by a
half-space model.
We present preliminary results of the spatial distribution of intrinsic attenuation
represented by the absorption path length, as well as of scattering attenuation in terms of
the mean free path and compare the outcomes to results from previous studies.
Furthermore catalog magnitudes are compared to moment magnitudes estimated during the
inversion process. Additionally site amplification factors of the stations are presented. |
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