SHIPS - Figure 3
(Top) East-west horizontal component recordings of the M7.6 Chi Chi earthquake of September 20, 1999. Dotted line shows locations of SKS and S-wave arrivals calculated from the iasp91 standard earth model. Data have been low pass filtered with an upper corner frequency at 0.25 Hz.
(Bottom) Relative amplitudes of compressional (triangles) and shear wave (asterisks) arrivals from the Chi Chi earthquake plotted against an approximate profile of the thickness of the Seattle basin. These amplitudes represent the relative amplitudes of the vertical component for P-waves and east-west horizontal (nearly radial) component for S-waves. The P-wave data were first low pass filtered with an upper corner frequency of 1 Hz; the S-wave data were low pass filtered with an upper corner frequency of 0.25 Hz.
