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| Bertrand, E; Deschamps, A; Virieux, J. |
| An investigation of the teleseismic P -wave coda is performed using the single-scattering approximation. The method allows one to image short-wavelength scale (less than or equal to2 km) velocity and density heterogeneities and structures that are barely detected by traveltime tomography. Source effects are removed by using receiver functions for data interpretation, but the amplitude (especially the sign of the signal) is synthesized. Both broad-band seismological stations in the southwestern Alps (France) and Campanian plain (Italy) are used for the illustration of the proposed method. Because of the large aperture of our arrays, laterally small-scale heterogeneities are difficult to image and we must assume lateral continuity of the detectable... |
| Tipo: Text |
Palavras-chave: Body waves; Broad-band; Crustal structure; Moho discontinuity; P-to-S conversions; Scattering; Waveform analysis. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00466/57762/60036.pdf |
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| Auger, E; Virieux, J; Zollo, A. |
| In this paper, we show how the migration of active seismic data can be used to identify and position a seismic discontinuity in a complex medium, and how the amplitude variations of the converted P to S waves can be interpreted to constrain the seismic velocities below the interface. For the application we turn our attention on Mt Vesuvius, an active volcano threatening a densely populated area. To better define its plumbing system, we investigate a mid-crust seismic discontinuity first identified by Zollo et al. (1996, Science, 274, 592-594) and assumed to be the top of a layer containing low-velocity material. We deduce a reference velocity model from previous works on first arrival times, and use it to migrate PP reflected and PS converted waves. In the... |
| Tipo: Text |
Palavras-chave: Crustal structure; Explosion seismology; Low-velocity layer; S waves; Seismic tomography; Volcanic structure. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00466/57760/60035.pdf |
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