Global multiresolution models of surface wave propagation: comparing equivalently regularized Born and ray theoretical solutions |
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| Authors: | Lapo Boschi |
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| Institution: | Dpt. Geofísica i Tectònica, Institut de Ciències de la Terra 'Jaume Almera' IJA-CSIC, Lluís Soléi Sabarís s/n, 08028;Barcelona, Spain. E-mail: Dpt. Geología, Universidad de Oviedo, Arias de Velasco s/n, 33005;Oviedo, Spain |
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| Abstract: | I invert a large set of teleseismic phase-anomaly observations, to derive tomographic maps of fundamental-mode surface wave phase velocity, first via ray theory, then accounting for finite-frequency effects through scattering theory, in the far-field approximation and neglecting mode coupling. I make use of a multiple-resolution pixel parametrization which, in the assumption of sufficient data coverage, should be adequate to represent strongly oscillatory Fréchet kernels. The parametrization is finer over North America, a region particularly well covered by the data. For each surface-wave mode where phase-anomaly observations are available, I derive a wide spectrum of plausible, differently damped solutions; I then conduct a trade-off analysis, and select as optimal solution model the one associated with the point of maximum curvature on the trade-off curve. I repeat this exercise in both theoretical frameworks, to find that selected scattering and ray theoretical phase-velocity maps are coincident in pattern, and differ only slightly in amplitude. |
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| Keywords: | aftershocks parameters clustering analysis Pamplona fault seismicity temporary array western Pyrenees |
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