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Detailed Reference Information |
Tong, J., Dahlen, F.A., Nolet, G. and Marquering, H. (1998). Diffraction effects upon finite-frequency travel times: A simple 2-D example. Geophysical Research Letters 25: doi: 10.1029/98GL01291. issn: 0094-8276. |
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The widespread availability of broad-band digital seismic data makes it possible to measure travel-time anomalies by cross-correlation with spherical-earth synthetic seismograms. Finite-frequency diffraction effects render such measurements sensitive to wave-speed perturbations off of the infinite-frequency geometrical ray path. We show, by consideration of a simple 2-D example, that the Born approximation provides an excellent description of these off-path sensitivity effects, in the absence of caustics and for travel-time shifts that are small compared to the wave period. Remarkably, an isolated low-velocity anomaly may produce fringing fast travel-time anomalies, as measured by cross-correlation. ¿ 1998 American Geophysical Union |
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Abstract |
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Keywords
Seismology, Seismology, Body wave propagation, Seismology, Theory and modeling |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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