Surface wave phase velocities in Finland

Abstract

Abstract Phase velocities of Rayleigh waves in Finland have been measured by the Fourier analysis method, using records of three stations which are on almost the same great circle as several Greek earthquakes. Phase velocities of Love waves of two of these earthquakes have also been determined. The wave groups were divided by numerical filtering into two frequency channels, which were analyzed separately. The resulting phase velocity curves were then smoothed in order to remove rapid oscillations, and mean values were calculated. The phase velocities were found to be slightly lower than those found for the Canadian Shield (Brune and Dorman, 1963), the maximum deviation for Rayleigh waves being about 0.07 km/sec at a period of 28 seconds and for Love waves about 0.15 km/sec at a period of 32 seconds. At periods shorter than 40 seconds the phase velocities of Rayleigh waves were found to be equal in Northern and Southern Finland within the accuracy of measurement.