Despite discovering more faults under Canterbury, geologists say they are no closer to predicting future earthquakes.
The possibility of future devastating earthquakes in Christchurch was discussed today at the Christchurch earthquake Royal Commission, where scientists have cautiously put a number on the risk factor.
Since September 4 last year Canterbury has been rocked by almost 8000 aftershocks.
"In Canterbury we have shallow earthquakes, typically the most damaging," Canterbury University's Professor Jarg Pettinga said.
While the effects of the shakes are obvious, working out where the fault lines are proves more difficult.
But as of 1998, studies revealed that there was in excess of 100 active faultlines in the region and in addition to that there are still a number of hidden faultlines under the subsurface, Pettinga said.
"Any number of those faults can rupture at anytime when the stresses are built up," Pettinga said.
As a result of that, he said, more research is necessary.
"We recognised that we had significant gaps in our knowledge of the subsurface geology. And there were some imperatives for us to get some more detailed understanding of the fault structure," he said.
While a lot of data has been collated since the September and February earthquakes, Pettinga said more is necessary.
However it can be very costly, running into the millions of dollars, he said.
This is because a lot of the machinery that is needed for the testing has to be shipped in from overseas, and it requires specialist teams to actually undergo the tests, he said.
Also the gravel in the Canterbury area is very thick and he said this makes it difficult to decipher whether the faultlines are actually active or not, Pettinga said.
Scientists also warn that predicting earthquakes is not an exact science; it's based on data from previous quakes and working on that basis, the Commission heard today that there is a 14% likelihood of a magnitude 6 earthquake or greater in the next year.
"We've got to really plan around this - it's something we shouldn't be living in fear of," said Dr Terry Webb of GNS Science, who spoke at the Commission yesterday.
The Commission will now keep this in mind when working out what the risks mean for the rebuilding of Christchurch.
Full information about the inquiry, including live streaming when in session, here .
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