The economic impact of the second Christchurch earthquake is expected to top $NZ15 billion ($10.95 billion), but the insurance losses will be difficult to apportion between the two quakes, according to Aon Benfield.

The Monthly Cat Recap published by Impact Forecasting, Aon’s catastrophe modeller, says determining insured loses will be “extremely difficult and complex given the intermingled nature of the damage stemming from the earthquake of September 2010 and this latest earthquake”.

It notes the NZ Government has estimated a damage bill of $NZ10 billion-$15 billion ($7.3 billion-$10.95 billion) from the second quake.

Impact Forecasting President Steve Jakubowski says the NZ Earthquake Commission has already received more than 31,500 insurance claims and that figure is expected to rise significantly as the situation on the ground becomes clearer.