For the first time, scientists have brought local councils, iwi and civil defence orginisations together this week to share their knowledge and debate how New Zealand would cope with a devastating megathrust earthquake.
Experts warn a potential 8.4 magnitude quake off the east coast could release 2,000 times more energy than the 2011 Christchurch Earthquake.
The risk is the Hikurangi subduction zone, a massive fault line running from Marlborough and right past the East Coast where the Pacific and Australian tectonic plates collide.
GNS Scientist Doctor Laura Wallace told 1 NEWS "it's a massive plate boundary fault and subduction zones because they're so large have the potential to produce the worlds largest earthquake and tsunamis."
Marcus Hayes-Jones from Napier Civil Defence said he "can't emphasise how serious" New Zealand must take this "genuine risk."