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The Airy ellipsoid is still used by the Ordnance Survey in Great Britain. (Northern Ireland has a different national grid based on a different geodetic system.)
by robinhouston 11y ago
The Airy ellipsoid is still used by the Ordnance Survey in Great Britain. (Northern Ireland has a different national grid based on a different geodetic system.) WGS84 may be increasingly “the standard”, but it isn't the only geodetic system in widespread use. ETRS89 is anchored to the European continental plate, and is therefore slowly drifting out of sync with WGS84.
- david-given 11y agoThe more I learn about mapping, geodetic systems and elipsoids, the more I am coming to the conclusion that deciding to live on a planet made out of squishy goo was a bad idea.
- jerf 11y agoIt is commonly thought that life would be much harder on a volcanically-inactive world due to the fact the volcanic activity cycles nutrients on a geological time-frame that would otherwise tend to collect on the bottom of the ocean. See http://earthobservatory.nasa.gov/Features/CarbonCycle/page2.php http://earthobservatory.nasa.gov/Features/CarbonCycle/page2.... for instance, though it doesn't quite make this exact point, you can see how it might be a problem if all the carbon on a planet is locked up in rocks on the ocean floor after a mere 250 million years.
- mikeash 11y agoYes, I would like to find the person responsible for this decision and give him a piece of my mind.
- pauldino 11y agoAnd in the United Status, 95% of USGS maps use NAD27.
- sxcurry 11y agoI believe that USGS maps published after 2009 use NAD83, which for practical purposes is identical to WGS84 used by GPS. Also, beginning in 1984, older maps have both NAD83 and NAD27 tick marks. If in doubt, check the datum designation at the bottom of the map.