Cape Campbell after uplift during the Kaikōura earthquake in November 2016.

The top of the South Island is creeping closer to the North Island as the land continues settling after the November 2016 Kaikōura earthquake.

The massive forces released by the magnitude 7.8 quake on November 14, 2016, had immediate effects on the North Canterbury and Marlborough landscape.

But the changes unleashed have not finished yet, with post-quake monitoring showing Cook Strait is getting narrower as the northern part of the South Island edges northeast.

KAT PICKFORD Cape Campbell, looking across Cook Strait to Wellington.

The difference in the South Island's shape could be seen if a large enough map of central New Zealand as it is today could be laid over one on November 13 two years ago.

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The Kaikōura quake tore apart 25 faults as it raced northwards from its epicentre close to Waiau, North Canterbury, through to the shores of Cook Strait.

SUPPLIED New land exposed after the November 2016 earthquake near Cape Campbell.

Over about a minute-and-a-half, parts of the Marlborough coast were lifted more than 6 metres in places and dropped more than 2m in others. Land was shunted horizontally by 12m along the Kēkerengū Fault and vertically by as much as 9m along the Papatea Fault.

Global Positioning System (GPS) monitoring stations installed by GNS Science and the University of Otago across the quake zone in the days after the main shock show the fastest movement in the past two years since then has been at Cape Campbell.

GNS Science geodetic scientist Dr Sigrún Hreinsdóttir​, who has been analysing the creep towards the North Island, said Cape Campbell had moved northeast and was now about 35 centimetres closer to Wellington than before the quake.

Other GPS sites showed Kaikōura had slid about 15cm further east, Blenheim was now 15cm further northeast towards Cook Strait, and Nelson had slipped about 5cm southeast.

Sites in the Marlborough Sounds had moved northeast by about 10cm, but land around the Waiau epicentre had barely moved.

Wellington had also shifted about 5cm northeast since the quake, she said.

It was difficult to quantify how much post-quake creep was due to slip on the subduction zone below the region or "after slip" on the Needles, Kēkerengū and Jordan faults, 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."

﻿More recent measurements indicated the creep was continuing but at a slower rate, Hreinsdóttir said.

Hreinsdóttir was the leader of the Natural Hazards Research Platform's report on post-Kaikōura quake deformation.

The report says the land creep from such a large quake will continue for years, with further slip on crustal faults, "viscoelastic response" of the lower crust and upper mantle and further possible slip on the subduction interface.