More than 5000 people reported feeling the quake.

A "severe" earthquake has shaken Wellington and the upper South Island.

The 5.1 magnitude earthquake was centred 15 kilometres east of Seddon, at a depth of 11km.

GeoNet initially recorded the quake as being a 5 magnitude, and rated it as strong. It has since been upgraded to severe.

123RF A "severe" earthquake in Seddon has been felt in Wellington and nearby towns.

More than 5000 people reported feeling the shaking across the lower North Island, and throughout the South Island.

READ MORE

* First section of quake-damaged Wellington Reading car park demolished

* Thousands of trucks forced on to roads as Wellington port cranes sit idle

* Magnitude 5.5 earthquake in Cook Strait shakes Wellington

GeoNet duty seismologist Anna Kaiser said the quake was an aftershock from the November Kaikoura quake.

"It's been a very busy place. This is part of the normal and expected behaviour of aftershock sequences."

Kaiser said we could expect more quakes in the future. This quake itself was likely to cause some smaller aftershocks.

"A 5.1 is quite moderate in the whole scheme of the Kaikoura rupture, but sometimes when you get an earthquake of that size you invigorate the area. Typically you might see some smaller aftershocks in the short term."

KiwiRail said the line between Picton and Blenheim had been stopped while checks on the line were made, but had since reopened.

In Wellington, routine checks would be carried out across the rail network.

The earthquake hit at 1.19pm on Wednesday, jolting office workers across the capital.