129th meridian east

Line across the Earth
129°
129th meridian east
In Australia the meridian nominally defines the eastern border of Western Australia with the Northern Territory and South Australia.

The meridian 129° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, Australia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole.

The 129th meridian east forms a great circle with the 51st meridian west.

In Australia, the meridian nominally defines the eastern border of Western Australia, and the western borders of the Northern Territory and South Australia.[1] However, the border of Western Australia actually meets the Northern Territory border and South Australian border at the 26th parallel south, at what is known as Surveyor Generals Corner.[2]

  1. ^ "Border Lengths - States and Territories: Western Australia - South Australia - Northern Territory border". Geoscience Australia, Government of Australia. 2021. A glance at most maps of Australia will tell you something that isn't quite true. The border which runs along the eastern edge of Western Australia is not actually one continuous straight line. [...] The [1922] agreement set out the border as being a line determined by the 129th meridian east longitude. However, the agreement required that the boundary be defined by lines running north and south [...] and in June 1968 two monuments approximately 127 metres apart were erected at the junction of the boundaries.
  2. ^ Porter, John (April 1990). AN HISTORICAL PERSPECTIVE - Longitude 129 degrees east, and why it is not the longest, straight line in the world. National Perspectives: 32nd Australian Surveyors Congress Technical Papers 31 March - 6 April 1990. Canberra: The Institution: Eyepiece - Official Organ of The Institution of Surveyors, Australia, W.A. Division. pp. 18–24. Porter.