Scientists have told the Canterbury Earthquakes Royal Commission that the likelihood of further quakes and aftershocks is starting to lessen, but an elevated hazard level will persist past one year.

Work by government-owned geoscience body GNS Science and the University of Canterbury calculated a probability of 2% of an earthquake of over 7 magnitude in the year to September. The chance of a 6-7 magnitude quake was 14%.

The February 22 quake, which caused most damage and 182 deaths, measured 6.3, while the first quake on September 4 was 7.1 and started the sequence.

The royal commission is inquiring into building failure resulting from the earthquakes, and has begun public hearings with experts discussing soil and seismic issues.

GNS scientists told the inquiry they warned of further aftershocks following the Boxing Day earthquake, but did not warn of the likelihood of another major earthquake.

They told the royal commission there were concerns of the effect such a warning would have on an already traumatised population.