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| Titel |
The Imprint of Water Column Resonance in Microseismic Source Spectra |
| VerfasserIn |
Matthias Meschede, Eleonore Stutzmann, Véronique Farra, Martin Schimmel, Fabrice Ardhuin |
| 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 |
250145105
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| Publikation (Nr.) |
 EGU/EGU2017-9005.pdf |
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| Zusammenfassung |
| We have collected day averaged source spectra from five years of secondary
microseism body waves observed by arrays in North America. These source spectra
have distinct spectral characteristics: In particular, we observe that their
dominant frequency is often around 0.13--0.15Hz or 0.19--0.21Hz but rarely in
between these two bands. Subdivision of our dataset into clusters of similar
sources reveals that the shapes of secondary microseism body wave spectra are
clearly tied to distinct geographical regions. Comparison with synthetic
spectra that are computed using models based on ocean wave hindcasts shows that
we are able to accurately predict these observations. However, modelling is
only able to reproduce the observed spectra when resonance effects in the water
column are taken into account. The spectral double peak that we have observed
can therefore be explained as a consequence of the particular distribution of
ocean depths. Our quantitative assessment of secondary microseism P-waves shows
that models have reached a quality that allows to invert for diverse parameters
of subsurface and ocean state. |
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