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A geometricla error in some Computer Programs based on the Aki-Christofferson-Husebye (ACH) Method of Teleseismic Tomography

January 1, 2000

Some computer programs based on the Aki-Christofferson-Husebye (ACH) method of teleseismic tomography contain an error caused by identifying local grid directions with azimuths on the spherical Earth. This error, which is most severe in high latitudes, introduces systematic errors into computed ray paths and distorts inferred Earth models. It is best dealt with by explicity correcting for the difference between true and grid directions. Methods for computing these directions are presented in this article and are likely to be useful in many other kinds of regional geophysical studies that use Cartesian coordinates and flat-earth approximations.

Citation Information

Publication Year 2000
Title A geometricla error in some Computer Programs based on the Aki-Christofferson-Husebye (ACH) Method of Teleseismic Tomography
DOI 10.1785/0119990169
Authors B. R. Julian, J.R. Evans, M.J. Pritchard, G. R. Foulger
Publication Type Article
Publication Subtype Journal Article
Series Title Bulletin of the Seismological Society of America
Index ID 70022122
Record Source USGS Publications Warehouse