It's even stranger. NAD83, the North American Datum is tied to the North American plate. In the 80's, NAD83 and WGS84 were essentially identical - differed by millimeters. Now they are several feet apart as the North American plate moves about 1 cm per year.
Many years ago (early 80's) I taught a short class in geodetics, and a geodecist I worked with made a viewgraph for me showing how a particular well offshore Angola would move by up to a kilometer depending on which geodetic datum you attached its lat-long to. There are many local datums, designed to better approximate local topography. I spent a lot of effort teaching people that knowing the lat-long of a point did NOT tell you where it was on the earth. You also needed to know the datum.
<3 Amazing! Now I'm never going to look at locations the same ever again and this'll cause so much hilarious trouble for me in the future as I overthink things.
It's even stranger. NAD83, the North American Datum is tied to the North American plate. In the 80's, NAD83 and WGS84 were essentially identical - differed by millimeters. Now they are several feet apart as the North American plate moves about 1 cm per year.
Many years ago (early 80's) I taught a short class in geodetics, and a geodecist I worked with made a viewgraph for me showing how a particular well offshore Angola would move by up to a kilometer depending on which geodetic datum you attached its lat-long to. There are many local datums, designed to better approximate local topography. I spent a lot of effort teaching people that knowing the lat-long of a point did NOT tell you where it was on the earth. You also needed to know the datum.
<3 Amazing! Now I'm never going to look at locations the same ever again and this'll cause so much hilarious trouble for me in the future as I overthink things.