Residents of the Port Hills in Christchurch were told on Saturday how scientists assessed the risk of death associated with their properties.
They were also told more about the geotechnical data that ultimately led to their homes being red or green zoned after the Canterbury earthquakes.
GNS Science and the Port Hills Geotechnical Group examined the properties and wrote reports that were used by the Canterbury Earthquake Recovery Authority to underpin its zoning decisions.
Two seminars on cliff collapse and rockfall were held by the head of Canterbury University's Geological Sciences Department, Jarg Pettinga.
