Australia's lat and lon coordinates out by 1.5m

[GBW]

The continent of Australia is on the move and experts at Geoscience Australia are trying to keep up.

A team of scientists is about to recalculate the nation's latitude and longitude coordinates, which are currently out by more than 1.5 metres.

It will improve the accuracy of all spatial information across the nation for a myriad of services including transportation, personal navigation and surveying.

The framework currently in use, known as the Geocentric Datum of Australia, was last updated in 1994.

Because Australia sits on the fastest moving continental tectonic plate in the world, coordinates measured in the past continue changing over time.

The continent is moving north by about 7 centimetres each year, colliding with the Pacific Plate, which is moving west about 11 centimetres each year.

Earthquakes are caused when the build-up of tension between these plates is released.

Dan Jaksa from Geoscience Australia is working on the modernisation program.

He said the renewal was essential because there was a growing gap between the current positions and the coordinates used by Global Navigation Satellite Systems, such as GPS.

"We have points on Australia that are fixed to Australia and the lines of latitude and longitude move with those points," he said.

"The lines are fixed to the continent but as time goes by, that position compared to a GPS position can create a difference, so every so often we need to change that."

The new datum will be published early next year but will be based on projections to 2020, which means in 2017 the data will be out by about 20cm but that gap will slowly close each year.

Large earthquakes often change the shape of a continental plate.

For example, a magnitude 8.1 earthquake that struck north of Macquarie Island on December 23, 2004 — the day before the devastating Indian Ocean tsunami — shifted the distance between Sydney and Hobart by millimetres and caused a noticeable tsunami in Hobart.

http://www.abc.net.au/news/2016-07-28/a ... ts/7666858

[north-north-west]

One and a half metres, you say? A whole 1.5 metres!!!!! Gee, it's a wonder we don't all get lost . . .

[GPSGuided]

So the question is, what to do with all our current maps on GDA94? I'm lost for good!

[Son of a Beach]

My paper maps are all AGD66 anyhow, so I don't think I'll notice the difference so much.

How many years before the rest of King Island moves into zone 55? My OCD nature wants it fixed! Or are we moving the other way?

[frenchy_84]

We are moving NNE. You can get away with using zone 55 for all of King Island. It's abit of a novelty (in a boring geeky way) doing work there that the scale factor (for scaling between ground and grid distances) is >1 due to being so close to the edge of the zone.

[wander]

Would it be easier to stop the movement than deal with all the red tape of the new grid and maps and stuff? Surely there is some mining kit that is under utilised that we can use for this?

The Barrier Reef is up on the Continental plate is it not? So we will not run over that?

[Son of a Beach]

We are moving NNE. You can get away with using zone 55 for all of King Island. It's abit of a novelty (in a boring geeky way) doing work there that the scale factor (for scaling between ground and grid distances) is >1 due to being so close to the edge of the zone.

Sure, as we have been doing for decades... but that's exactly the problem I was referring to. To "get away" with it is not enough for OCD. Trouble is, it will be centuries... millenia... until my OCD will be truly satisfied with King Island's situation.

I think Wander has the right idea for the whole country. It may be easier to dig up the coast on one side of the island and then dump it on the other at the same rate it moves.

[hikingoz]

All the more reason to chuck the technology and navigate by topography.