Hon Maurice Williamson
Minister for Land Information
14 August 2013 Media Statement
Innovation supports Canterbury infrastructure
Land Information Minister Maurice Williamson says an innovative approach to maintaining the geodetic datum has enabled
the repair of vital infrastructure as part of the Canterbury rebuild.
Geodetic datum defines the size and shape of the part of the Earth that includes New Zealand, and also defines NZ’s
position relative to the rest of the world. The geodetic datum was distorted by the Canterbury earthquakes.
“Canterbury’s geodetic control network had to be re-established to support the efficient reinstatement of essential
network utilities, such as sewerage and drainage.
“Land Information New Zealand undertook a significant re-survey programme of around 3,500 survey control marks to
restore the geodetic datum.
“Some marks were surveyed as many as four times, providing an immediate response to support the repair of key
infrastructure following each of the major earthquakes. The data was used by GNS to gain a greater understanding of
the ground movements and earthquake mechanisms,” Mr Williamson says.
Surveyors continue to efficiently and effectively undertake both routine cadastral surveys and specific surveys to
enable post-quake re-building, and to ensure certainty of property boundaries and property rights.
“LINZ has also developed mathematical models of the ground movement caused by the earthquakes, with models incorporated
into the datum to account for this movement and maintain the accuracy of the system.
“Through this innovative approach, LINZ is making a vital contribution to the region, and is a demonstration of the
Government’s commitment to the rebuild of Canterbury,” Mr Williamson says.
ENDS