A moderate earthquake has rattled the top of the South Island, 25km south east of Seddon.

The 4 magnitude aftershock follows a 4.6 magnitude quake in the early hours of this morning.

The strong quake struck south of Wellington in the Cook Strait, jolting people in the centre of the country awake.

So far 54 people have reported feeling the smaller shake, which struck at 19km deep shortly before 10.30am.


The quake was initially classed at 3.9 magnitude but Geonet has since upgraded it to 4.

It was followed by two lighter aftershocks in a similar area, recorded by Geonet as being 3.7 and 3.4 magnitude about ten minutes apart.

Thousands of aftershocks have kept those in affected areas on edge since the 7.8 magnitude quake on November 14.