The 4.6 magnitude earthquake struck near Porirua just after 11pm last night. Image / GeonetThe 4.6 magnitude earthquake struck near Porirua just after 11pm last night. Image / Geonet

GeoNet's shaking layers map for last night's 4.6 magnitude earthquake, which was centred offshore 30km north-west of Porirua. Image / GeonetGeoNet’s shaking layers map for last night’s 4.6 magnitude earthquake, which was centred offshore 30km north-west of Porirua. Image / Geonet