New Zealands North and South islands are creeping closer together in the wake of the devastating Kaikoura earthquake two years ago, the national science body has revealed.
The 7.8 magnitude quake struck the upper South Island in 2016, and initially brought the two landmasses five metres closer together but GNS Science has now found that unsettled fault lines continue to draw them ever nearer.
GNS Science geodetic scientist Dr Sigrn Hreinsdttir told Stuff that Cape Campbell at the top of the South Island was now about 35cm closer to Wellington since the quake, reports The Guardian.
Hreinsdttir said it was difficult to identify which fault was responsible for the post-quake creep. In reality we are having all this creeping going on and the question is, which [fault] is the dominant factor?
Hreinsdttirs team said the South Islands creep towards the North would continue for years yet, but that the rate of movement will slow.
After the quake, researchers identified that the quake had also raised some areas of land by eight metres. They described the quake as complicated and said it drove a thorough rethink on earthquake science after a world-record 25 faults opened up.
Numerous studies by local and international scientists of the Kaikoura quake are being carried out, as the data collected at the time is some of the best in the world, utilising satellite images, field observations, GPS and coastal uplift data.
GNSs principal scientist Dr Kevin Berryman said, It was certainly unusual that 25 faults ruptured simultaneously in the Kaikōura earthquake.
Its fair to say that all earthquakes of magnitude 7.5 and above are invariably very complex We have to be prepared to live with a level of risk, but we should be asking how much risk is acceptable?
Its a challenge for us [New Zealand] to provide expected levels of services when confronted by such high levels of geological hazard.