GeoNet downgrade risk of second big quake to 15 per cent
GeoNet has revised their Kaikoura quake aftershock forecasts, downgrading the risk of another large earthquake.
They now put the odds of another earthquake between M6.0 and M6.9 hitting within 30 days at 15 per cent, down from 18 percent in February.
The chances of another quake at M7.0 or higher is down in the next 30 days is down to 1 per cent from 2 per cent in February.
"We like this downward movement in our forecast; it is good step in the right direction," GeoNet scientists wrote in their release.
"But does this mean we are all in the clear and don't need to worry about more big earthquakes? No, absolutely not. Another big earthquake is still well within the probabilities in our models. A 15 per cent chance in a month is still a concerning probability."
"We need to continue to be prepared for earthquakes as these will go on for years to come. The ongoing Canterbury Earthquake Sequence is an example of aftershocks that can last for years after the initial mainshock."
Since the M7.8 earthquake in November 14796 quakes have been recorded by GeoNet. Four of them were at M6.0 or greater, with 56 between M5.0 and M5.9.
On a wider timeframe, the chance of large aftershocks is higher.
There is a 10 per cent chance another M7.0 or larger aftershock will hit in the next year, and a 68 per cent chance one between M6.0 and M6.9 will occur.
The aftershocks from the Kaikoura earthquake would mostly affect the immediate area surrounding Kaikoura.
The probability of an aftershock that causes internal building damage and strong shaking within the next year are as high as 20 per cent in Kaikoura. They are at just 3 per cent in Wellington.
GeoNet do not include projections of earthquakes on other faultlines in these calculation tables.
The Alpine Fault still has a 30 per cent chance of rupturing in the next fifty years, causing significant damage to the South Island.