40th parallel

[david_adam]

 

Here's a photo not many of you may have seen.

 

Taken on Flinders Island. Apparently the 40th parallel south only crosses 4 land masses (Flinders & King Is, N.Z. [North Is], South America [Chile & Argentinia].

 

Now a question. The location is marked on the major roads on Flinders Is. but the GPSr shows it about 246m away (south). Any ideas why?

 

David

[+akkatracker]

go to forum.geocaching.com.au

[david_adam]

and??

[+The Spindoctors]

David

 

I think akkatracker meant to say that most geocachers in Australia chat on the Forums on the above-listed website.

 

Having said that I'm happy to offer a reason why there may be a difference. It might be the datum of the coordinate system used. Your GPS using WGS84 (AGD84), while the sign on Flinders Island may be based on the old AGD66 system. Each coordinate system assumes a slightly different shape for the Earth. See: http://www.ga.gov.au/earth-monitoring/geodesy/geodetic-datums/about.html

 

BTW - I've been to Greenwich and found the zero longitude line to be about 120 metres away from the actual line - same reason. http://gpsinformation.net/main/greenwich.htm and http://coord.info/GCK7HH

 

and??

[+Huntleigh]

 

Here's a photo not many of you may have seen.

 

Taken on Flinders Island. Apparently the 40th parallel south only crosses 4 land masses (Flinders & King Is, N.Z. [North Is], South America [Chile & Argentinia].

 

Now a question. The location is marked on the major roads on Flinders Is. but the GPSr shows it about 246m away (south). Any ideas why?

 

David

 

You might be interested in another GPS game, the Confluence Project

 

Two for the 40th parallel in Oz:

King Island

Flinders Island

 

You can even get geocaches on the parallels: Thirty-nine South

[david_adam]

Thanks, Huntleigh. That project is fascinating. Very few unfound in my neck of the woods! Might be interesting to re-visit some just to see the numbers on the GPS! Gee - we're a weird mob!!!

 

David