| Abstract: | Summary In this paper two methods for analysing in real time (or on line) microseisms recorded near a coast, with the aim to deduce their fundamental periods and evolution, are presented. Firstly, the autocorrelation of microseisms as a random signal is derived, whereas the second method consisting in a frequential filtering is more extensively used. The application of these methods is also made for simultaneously recorded microseisms in Genoa and in Vesima-Arenzano (station placed just on shore-line). The results show that in Genoa the peak amplitude ratio between secondary and primary microseisms is varying in the range of 3–28, whereas in Vesima this ratio is about the unity. This behaviour is explained on account of the different breaking zones for the two stations.Istituto Geofisico e Geodetico, Università di Genova, 16100 Genoa, Italy. Contribution No. 249. — This work has been supported by the  Consiglio Nazionale delle Ricerche (comitato Nazionale per le Scienze Fisiche), Roma . |
