Precursory seismic sequences in New Zealand

Abstract

The sequence of precursory swarm and gap has been confirmed in the local seismic activity preceding major earthquakes at Gisborne (1966), Seddon (1966), Inangahua (1968), and Hastings (1973). The magnitude of the main shock appears to be related to that of the largest swarm earthquake as well as to the precursor time. This suggests a method of prediction which might yield long-term estimates of location, magnitude, and time of occurrence.