Two strong earthquakes rattled the South Island overnight.
The first, at 11.32pm, was a magnitude 4.5 earthquake which struck just north of Tai Tapu, 10km southwest of Christchurch, at a depth of 11km.
GNS Science had measured the quake as a magnitude 5, but later revised it down.
The quake was felt strongly around Christchurch, and was reported as "slightly damaging" in Fendalton and Hoon Hay.
Just a minute later, a quake of a similar size struck near Blenheim.
