It was unlikely yesterday's quake would generate aftershocks, given its depth and relatively small size, Mr Ferris said.
"I'd be reasonably certain, going on past seismicity, that this was probably an event on its own."
GNS Science Geohazard duty officer Dr Tony Hurst said there was also a shallow quake which was widely felt northeast of Wanaka early yesterday.
The magnitude 3.5 shake, which occurred at 6.04am, was just 5km deep.
There was also a 150km-deep, magnitude 4.9 quake under Lake Taupo about 5pm yesterday.
It was unlikely that this earthquake would have been widely felt.
Dr Hurst said it was not unusual to have so many earthquakes in a day.
The large earthquake that shook the capital on Saturday was centred 40km west of Wellington and was widely felt in the capital and in Picton.
Dr Hurst said it occurred on either the Wairau Fault or on one of the numerous other faults that run parallel to it.
It was difficult to pinpoint which fault the earthquake occurred on because of how deep it was.
Wellington emergency services co-ordinator Fred Mecoy said the Meridian building in downtown Wellington was damaged and had sprayed the street on one side with broken louvres.
Glenn Hudson, a station officer at Thorndon fire station, said about a dozen louvres or shutters had come loose from the second storey of the north side of the Meridian Building on Customhouse Quay.
The Wagamama restaurant below was "full of happy diners" who felt the shake but the restaurant remained open.
"The danger was that they [louvres] would fall off and hit passers-by so we cordoned off the area, made the area safe," he said.
Dairies reported stock had dislodged from shelves in the shake and weekend workers in central Wellington buildings dived under desks and into doorways as the tremor built to a rolling climax.
Newtown resident Donald McDonald said he felt the rumbling for about 10 seconds before a larger jolt.
Dr Hurst said about 1600 reports were registered with GeoNet within minutes of the shake.
