The non-geometric Pover-barS wave in high-resolution seismic data: observations and modelling

Détails

ID Serval
serval:BIB_1AEBD2056A4B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
The non-geometric Pover-barS wave in high-resolution seismic data: observations and modelling
Périodique
Geophysical Journal International
Auteur(s)
Roth M., Holliger K.
ISSN-L
0956-540X
Statut éditorial
Publié
Date de publication
2000
Peer-reviewed
Oui
Volume
140
Pages
F5-F11
Langue
anglais
Résumé
In data from a high-resolution seismic survey conducted over a near-surface
environment consisting of homogeneous soft clay, we consistently
observe a distinct seismic phase arriving between the direct compressional
wave and the Rayleigh wave. This phase is characterized by high amplitudes
at near offsets and a phase velocity corresponding to about twice
the shear wave velocity. Based on analytical and numerical analyses,
this signal could be unambiguously identified as a non-geometric
wave, which is excited if the source is located near the Earth's
surface and the Poisson's ratio in the vicinity of the source is
unusually high. To date there are only a few speculative observations
of this particular non-geometric seismic wave phenomenon. However,
given the commonly very high Poisson's ratio of surficial materials,
we expect this phase to be present, albeit unidentified, in many
near-surface seismic surveys. The presence of this non-geometric
wave increases the complexity of the seismic record, and failure
to identify it may result in misinterpretations, particularly of
high-resolution seismic reflection data as well as of shear wave
and surface wave data. Potential applications of this seismic phase
may arise from its high sensitivity to the shear wave velocity in
the immediate source region.
Open Access
Oui
Création de la notice
25/11/2013 18:27
Dernière modification de la notice
20/08/2019 12:51
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