Open AccessGlobal multiresolution models of surface wave propagation: comparing equivalently regularized Born and ray theoretical solutions
Author(s) -
Boschi Lapo
Publication year - 2006
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2006.03084.x
Subject(s) - parametrization (atmospheric modeling) , amplitude , anomaly (physics) , curvature , physics , phase velocity , surface (topology) , scattering , surface wave , mode coupling , phase (matter) , mode (computer interface) , born approximation , coupling (piping) , mathematical analysis , computational physics , statistical physics , geometry , mathematics , optics , quantum mechanics , computer science , mechanical engineering , engineering , radiative transfer , operating system
SUMMARY 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.