A survey buggy originally developed for the oil industry has begun searching deep under central Christchurch to find out whether there are more fault lines.
Scientists did not previously know about the faults at the site of February's earthquake under the Port Hills and the earthquake last September west of the city.
A joint team from Canterbury University and the University of Calgary in Canada has begun using seismic equipment along Barbadoes Street which can identify possible faults to a depth of several kilometres.
Canterbury University geology professor Jarg Pettinga says if there is another fault line they will know quite quickly.
Professor Pettinga says the team's findings will be used in determining building regulations.
