Hold on, everyone: Australia’s on the move, with its latitude and longitude due to shift nearly 2m early next year.
The continent moves about 7cm north-north-east every year because of the movement of the Earth’s tectonic plates.
But it means a gap between Australia’s latitude and longitude as it is shown on local coordinates, which move with their local continent – and global coordinates, which don’t.
The latitude and longitude given by modern global navigation satellite systems, such as GPS, are fixed to the rest of the world and as such offset as the Australian continent drifts over time.
The Geocentric Datum of Australia, the country’s local coordinate system, was last updated in 1994, and Australia is now about 1.5m further north-north-east (or, to give the metric used in a BBC infographic: about the height of a kangaroo).
Daniel Jaksa of Geoscience Australia, the body responsible for mapping the continent, told Guardian Australia the shortfall between the two systems would be addressed with an upcoming change.
“We’re working on moving Australia’s latitude and longitude to reflect our actual position in the world.”
Australia will shift its longitude and latitude by 1.8m in the direction of its tectonic motion from 1 January 2017, with the overcorrection meaning the local and global coordinates will align in 2020. Similar corrections were made in 1966, 1984 and 1994.
“This is the fourth time we’ve done this in the last 50 years,” Jaksa said. “The thing we’re doing differently here is we’re putting the lines of latitude and longitude further north-north-east to where Australia will be in January 2020.”
This means the update will remain current for longer.
Every nation does updates of this sort but Australia is located on the fastest-moving continental tectonic plate, which means more regular activity.
Jaksa said the fact the global coordinates did not reflect tectonic motion could have negative impacts for any technology that used that data – for example, in the future, self-driving cars.
“[The coordinates] we find in Australia for GPS are actually different to the local ones. It’s a problem for us when we want to integrate local mapping information with global systems like Google Maps or Apple Maps used on smartphones.
“It’s not just self-driving cars, it’s self-driving tractors, mining equipment – drones going around delivering pizzas that are currently being developed.”
Accurate, consistent data was also important for scientific investigation, Jaksa noted – “not just everyday mapping”.
He was hopeful the 2017 adjustment would be the last update of its kind, as Geoscience Australia eventually aims to move to a dynamic system that measures real-world coordinates by using the velocity of points on the continent.
“That will require quite a bit of technology change and innovation.”
