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Chatham Islands Transverse Mercator 1979 (CITM1979)

The Chatham Islands Transverse Mercator 1979 (CITM1979) used to be the projection for Topographic 1:50,000 and other small-scale mapping in the Chatham Islands. Chatham Islands Transverse Mercator 2000 (CITM2000) is now the official projection used in the Chatham

Read about Chatham Islands Transverse Mercator 2000 (CITM2000)

Chatham Islands Transverse Mercator 1979 (CITM1979) was a mapping projection used for topographic maps produced for the Chatham Islands. It was replaced by Chatham Islands Transverse Mercator 2000 (CITM2000). Separate projections have been defined for mainland New Zealand, the continental shelf and the other offshore islands:

CITM1979 was a transverse Mercator projection. This is cylinder-shaped projection that is suited for depicting an elongated area, like New Zealand, which extends in a north-south direction.

Find out more about projections

Information about converting coordinates between the CITM1979 and CITM2000 projections is available on the coordinate conversion pages:

Online coordinate converter

The key parameters of CITM1979 are summarised in the table below.
NameChatham Island Transverse Mercator 1979
AbbreviationCITM1979
EPSG number4673
Projection typeTransverse Mercator
Reference ellipsoidInternational 1924
DatumChatham Islands Transverse Mercator 1979
Origin latitude44° 00' 00" South
Origin longitude / central meridan176° 30' 00" West
False Northing650,000 metres North
False Easting350,000 metres East
Central meridian scale factor1.0000
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