Please use this identifier to cite or link to this item:
|Authors: ||Herrero, A.*|
|Title: ||Space-time and spectrum parameterization of seismic sources : applications to seismic risk|
|Other Titles: ||paramétrisation spatio-temporelle et spectrale des sources sismiques : applications au risque sismique|
|Issue Date: ||25-Feb-1994|
|Keywords: ||seismic hazard|
strong ground motion
empirical Green's function
|Abstract: ||The ground motion observation during an earthquake shows some similarity laws,
whatever the distance of the observation or the seismic source magnitude. This feature
appears in a particular shape of the record spectrum called ``omega square''.
Under some simplifying assumptions, obtaining such a spectral shape, in a kinematic
approach, needs a slip distribution with a spectrum inversely proportionnal to the squared
radial wavenumber, in the case of a constant velocity rupture associated with an instantaneous
slip rise time.
The numerical model developped in this thesis is based on a limited number of parameters as
magnitude and stress drop. Associating this self similary kinematic rupture process to
the isochrone concept and ray theory, the computation of the broad band S wave synthetics becomes
at any distance from the fault.
Nevertheless, the directivity effect of the rupture generated by such a model produces, as
classical models, large amplification factors at
high frequencies which are not observed. The observation
of spectra recorded during the Landers earthquake (1992) leads to a speculative interpretation
of the directivity effect degradation at high frequencies obtained by a perturbation of the rupture
direction at small wavelengths. A new model is developped in order to take into account this
This last model is used for an application to the seismic risk in the case of the Lambesc
earthquake (1909). A parametric study is achieved, which provides response spectra for a specific
site and a mapping of the seismic hazard associated to the fault in the region.
Finally, the similarity concept is applied to the small earthquakes summation technique to obtain
the effect expected for a large one. This approach, in comparison with classical approaches,
is not limited in high frequencies and allows to reconstruct more easily the intermediate
|Appears in Collections:||Manuscripts|
04.06.11. Seismic risk
04.06.03. Earthquake source and dynamics
04.06.04. Ground motion
Papers Published / Papers in press
Files in This Item:
|these.pdf||8.03 MB||Adobe PDF||View/Open
This item is licensed under a Creative Commons License
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.