Aftershocks may continue for weeks

2:34 pm on 4 September 2010

A geologist is warning aftershocks may continue to rattle the Canterbury region following Saturday's major earthquake.

A geologist at Canterbury University who lives in Avonside - one of the worst affected areas - says aftershocks of up to magnitude 5 are still occurring about every 30 minutes on Saturday.

Mark Quigley says aftershocks could continue for days or even weeks, but the most severe should subside within 48 hours.

He says much of the damage has been caused by liquefaction, in which water just below the surface is shaken and squeezed out.