Kaikōura earthquake brought the two islands five metres closer together in 2016

New Zealand's north and south islands are 'creeping' closer together in the aftermath of the devastating Kaikōura earthquake.

The 7.8-magnitude earthquake initially brought the islands five metres closer when it struck the tip of South Island in November 2016.

Now two years on, post-quake monitoring has revealed the land is still reshaping due to unsettled fault lines - with Cook Strait, the body of water between the two islands, narrowing.

The 7.8-magnitude earthquake initially brought the islands five metres closer when it struck the tip of South Island in November 2016 (file photo)

Police investigate the aftermath of the Kaikōura earthquake on a road in New Zealand's South Island

The northern part of South Island has been moving northeast towards its sister island since the quake, GNS Science revealed.

Dr Sigrún Hreinsdóttir​, a GNS Science geodetic scientist, told Stuff that Cape Campbell on the northeastern coast of the South Island is now 35 centimetres closer to Wellington.

Dr Hreinsdóttir also said GPS monitoring stations installed after the earthquake showed Kaikōura had moved 15 centimetres east, Blenheim had slipped 15 centimetres northeast and Nelson had moved five centimetres southeast.

The Kaikōura earthquake tore apart a record of 25 faults when it hit near to North Canterbury

The country's capital, Wellington, had also moved five centimetres to the northeast.

But the scientist said it was difficult to work out which fault line was responsible for each movement.

She said: 'In reality we are having all these creepings going on and the question is, which is the dominant factor?

'The idea there was a quite significant component on that plate interface was the surprising thing to us.'

Now two years on, post-quake monitoring has revealed the land is still reshaping due to unsettled fault lines (file photo)

Dr Hreinsdóttir said the land creep is likely to continue for years at a much slower pace.

The Kaikōura earthquake tore apart a record of 25 faults when it hit near to North Canterbury, on the tip of South Island.

It claimed the lives of two and caused dozens of injuries as parts of the Malborough coast were lifted more than six metres in some places and fell more than two metres in others.