| Abstract: | The surface-wave magnitudes of a selection of New Zealand earthquakes have been determined on a consistent basis using the ‘Prague formula’ and station corrections. The earthquakes range in magnitude from about 5 to 7.8, covering the instrumental period 1901–1988. Magnitudes for many of the earlier events had not been properly determined previously; and some significant discrepancies from the traditional magnitudes were found. The use of European station data (160° < D < 175°) is important to New Zealand because of its geographical isolation. These distant data were found to give consistently slightly higher Ms than closer stations, but could be used without bias through the station correction procedure. The relationship between Ms and ML was found for 31 ‘shallow’ New Zealand events and much of the scatter was explained as a function of depth. Significant differences in Ms/ML expressions from Europe and California were also found. The limited New Zealand data for Mw and M0 related well to Californian and global relationships with Ms. |
