P-wave seismograms from continuously varying transition zones—I. Acoustic media

Summary. The P -wave response from a class of acoustic transition zones with exponential variation in the velocity is studied in the frequency and time domains by means of contour integration in the complex k plane and the fast Fourier transform (FFT). Interesting relationships between received pulse shapes and velocity gradients inside the transition zone are observed. It is suggested that the models could be of practical interest, e.g. in interpreting observations from explosion seismology. For one model the results from the contour integral method are compared with those from the reflectivity method of Fuchs.