Discussion on Papers 5 and 6

DR BROWITT (Paper 6): Many of the disadvantages of the macroseismic method have been outlined but it clearly has an important part to play in modern seismology. Despite the subjective nature of the method we have found that increasing experience in sifting and interpreting the data has led to greater confidence in the results. This is illustrated in Fig.l (based on the same data set as Fig.6 of Paper 6) in which the histograms of event frequency against day of the week are

shown with the proportion of events reported felt

indicated by the double bars. No great effort was made to acquire the felt report data. The information came from about twelve regular reporters in the Loanhead-Polton area and spontaneous communication from local residents. About half of the events were reported felt and the histograms for these show the same pattern as