Centre of Australia
19 December 2001
One of the most asked questions of Geoscience Australia's national mapping area is where is the dead centre of Australia. While officially, there is no centre of Australia, you can use a number of methods to find a point somewhere between Alice Springs and Uluru. The problem is that each method provides a slightly different place.
The first method is using gravity. More than 50 000 digitised points representing the coastline of mainland Australia were assigned a unit weight. Using these points the gravity centre of Australia can be located at 23 degrees 7 minutes south latitude, 132 degrees 8 minutes east longitude.
In 1988 the Royal Geographical Society of Australasia determined, as a Bicentennial project, the geographical centre of Australia. A monument was erected to mark the location and named in honour of Bruce Lambert, a former Director of the Division of National Mapping, for his achievements in the national survey, levelling and mapping of the continent. Similar to the centre of gravity method, the location was calculated from 24 500 points at the high water mark of Australia's coastline. The computed result of the 1988 project was:25 degrees 36 minutes 36.4 seconds south latitude, 134 degrees 21 minutes 17.3 seconds east longitude.
The 'furthest point from the sea' method used a series of concentric circles drawn on transparent material placed over the top of a 1:5 million scale map of Australia until one circle was found to touch the coast at three points. The centre of the circle was then marked and the coordinates scaled from the map. This method resulted in a good agreement with the centre of gravity method and gave coordinates of: 23 degrees 2 minutes south latitude, 132 degrees 10 minutes east longitude
The median point was calculated as the midpoint between the extremes of latitude and longitude of the continent, giving the following coordinates:24 degrees 15 minutes south latitude, 133 degrees 25 minutes east longitude.
The Johnston Geodetic Station is a trigonometric survey cairn was built by officers of the Division of National Mapping in December 1965 and is the central reference point for all Australian surveys. It was named after Fredrick Marshall Johnston, former Commonwealth Surveyor General and first Director of National Mapping. It is located at 25 degrees 56 minutes 54.5 seconds south latitude, 133 degrees 12 minutes 30.1 seconds east longitude.
(So where is the dead centre? It's the local cemetery!)
Topic contact: firstname.lastname@example.org Last updated: October 4, 2013