Finding The Centre of Australia

Officially, there is no centre of Australia. This is because there are many complex but equally valid methods that can determine possible centres of a large, irregularly-shaped area - especially one that is curved by the earth's surface. The following are some of the ways in which the centres of Australia, its states and territories have been determined.

Furthest Point From The Coastline

To determine this, a series of concentric circles drawn on transparent material were moved over the top of a 1:5 million scale map of Australia until one circle was found to touch the coast at three points. Think of it as the largest perfect circle that could be drawn anywhere inside Australia that only just touches the coastlines. 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 procedure.

That location is 23 degrees 2 minutes south latitude, 132 degrees 10 minutes east longitude; position on SF53-13 Hermannsburg 1:250,000 and 5351 Glen Helen 1:100,000 scale maps.

Median Point

The median point was calculated as the midpoint between the extremes of latitude and longitude of the continent. Basically what this means is that a box was drawn around Australia, just touching the northern, eastern, southern, and western-most points on the continent. Lines were then drawn from the diagonals, with the intersection giving the following coordinates below. What's interesting though is this; both this method and the furthest point from the coastline method produce coordinates that are within the ball-park of the other weighted methods. That means that despite the irregular coastline, Australia's distinctive shape actually has a relatively high degree of symmetry

Median Point: 24 degrees 15 minutes south latitude, 133 degrees 25 minutes east longitude; position on SG53-01 Henbury 1:250,000 and 5549 James 1:100,000 scale maps.

Johnston Geodetic Station

This trigonometric survey cairn, situated about one kilometre north of Mt Cavenagh Homestead, was built by officers of the Division of National Mapping in December 1965, and was once the central reference point for all Australian surveys. It was named after Fredrick Marshall Johnston, former Commonwealth Surveyor General and the first Director of National Mapping. Today, surveys are based on the Geocentric Datum of Australia (GDA), a new and more accurate Australian coordinate system which has replaced the Australian Geodetic Datum (AGD) of which the Johnston station is a major part.

Location: 25 degrees 56 minutes 49.3 seconds south latitude, 133 degrees 12 minutes 34.7 seconds east longitude; position on SG53-05 Kulgera 1:250,000 and 5546 Kulgera 1:100,000 scale maps.

Australian Capital Territory

The centre of the Australian Capital Territory has been calculated as the former site of the Honeysuckle Creek Tracking Station, approximately 35km south-south-west of Canberra. The tracking station played a leading role in the NASA Apollo missions, closing in 1981 with the end of the Skylab program. The radio telescope was dismantled and relocated to Tidbinbilla in 1983.

Location: 35° 29' 24" South, 149° 00' 05" East

Position on SI55-16 Canberra 1:250,000 and 8726 Michelago 1:100,000 scale maps.

New South Wales

One possible definition of the centre for New South Wales is located just off Cockies Road, 33km west-north-west of Tottenham (Tottenham is 110km west of Dubbo). This spot, south of the Fiveways Intersection, is marked by a large cairn and sign, constructed for Australia's Bicentennial celebrations.

Location: 32° 09' 48" South, 147° 01' 00" East

Position on SI55-03 Narromine 1:250,000 and 8333 Tottenham 1:100,000 scale maps.

Northern Territory

The centre of the Northern Territory lies approximately 91 km west-north-west of Tennant Creek. A short distance past the Kartijirarrakanya Claypan, this centre is in a particularly harsh, arid part of the territory.

Location: 19° 23' 00" South, 133° 21' 28" East

Position on SE53-13 Green Swamp Well 1:250,000 and 5559 Lee 1:100,000 scale maps.

Queensland

The geographical centre is located 17km north-west of Muttaburra. Also famous from an archeological perspective, this region was once a pre-historic inland sea. A wealth of fossilised remains has been uncovered here, and when a previously undiscovered species was found, it was became known as the Muttaburrasaurus.

Location: 22° 29' 13" South, 144° 25' 54" East

Position on SF55-09 Muttaburra 1:250,000 and 7753 Culloden 1:100,000 scale maps.

South Australia

Despite three sides of it's border being straight lines, defining the centre of South Australia is no easier thanks to an irregular shaped coastline. According to one method, the centre is near the Churchill Smith bore, which is approximately 12km north-east of the Mt Eba cattle station. In relation to more commonly known landmarks, the centre of South Australia is located some distance south-west of Lake Eyre.

Location: 30° 03' 30" South, 135° 45' 48" East

Position on SH53-11 Kingoonya 1:250,000 and 6037 Eba 1:100,000 scale maps.

Tasmania

One possible centre for Tasmania is found on the western shore of Little Pine Lagoon. This small lake lies next to the Marlborough Highway, between the towns of Bronte and Miena. On the Lyell Highway, just a short distance east of Bronte, lies a cairn which was erected in 1983 by members of the Institution of Surveyors (Australian Tasmanian Division). This marker commemorates the early surveyors who explored and mapped the state, and marks Trig Point 715 - said to be near the geographical centre.

Location: 42° 01' 17" South, 146° 35' 36" East

Position on Tasmania South East 1:250,000 and 8214 Meander 1:100,000 scale maps.

Victoria

Located around 10km south-south-east of Bendigo, the centre of Victoria might be considered to be on the steps of the Mandurang Uniting Church. No longer in use, the church sits on the site that corresponds with centroid calculations from a number of different organisations, including Geoscience Australia, the Department of Natural Resources and Environment (DNRE), and the Department of Geospatial Science, Royal Melbourne Insitute of Technology (RMIT).

Location: 36° 51' 15" South, 144° 16' 52" East

Position on SJ55-01 Bendigo 1:250,000 and 7724 Bendigo 1:100,000 scale maps.

Western Australia

What could be called the centre is found in the Gascoyne Region, south-east of the Carnegie Homestead (on the Gunbarrel Highway).

Location: 25° 19' 41" South, 122 deg 17' 54" East

Position on SG51-06 Stanley 1:250,000 and 3446 Coonabildie 1:100,000 scale maps.