Scientists have tried to assess what impact slow-slip events under the lower North Island following the Kaikoura Earthquake will have on the probability of another massive quake but acknowledge it is "a work in progress". The estimated probability of a massive earthquake under central New Zealand has risen due to a rise in slow-slip activity, but such a quake remains "very unlikely". GNS Science said the chance of a quake as big or bigger than the magnitude 7.8 Kaikoura Earthquake in the coming year had now been put at 5 per cent - up from 3 per cent. That is about six times larger than the probability before the November 14 Kaikoura quake. The rise in the probability was due to ongoing slow-slip events following the earthquake on a large area of the tectonic plate boundary underneath the North Island, a GNS blog said. Due to the large extent of slow-slip events, the adjusted forecast also covered a larger area than the standard aftershock area, taking in the lower half of the North