Off on a bit of a tangent but this question has me thinking about the
existence of "palaeo maps" showing tectonic plate or terrain
locations over (geologic) time in a MapInfo (or readily convertible)
format. Has anyone come across such layers?
Declan
It all does move, but I wouldn't call it "degrading", but "Changing
over time".
But it doesn't make a lot of difference 'cause almost all
measurments are local to a single techtonic plate, and so are
indifferent
to large scale movements and rotations. So the claim to high accuracy is true,
As I see it, large scale movements are important to be aware of, but
not a problem in normal day-to-day work. I think you're safe to
leave it with the geodesists :-)
Best regards/Med venlig hilsen
Lars V. Nielsen
GisPro, Denmark
http://www.gispro.dk/
----- Original Message -----
From: "Spencer Simpson" <[EMAIL PROTECTED]>
To: "'MapInfo-L'" <[EMAIL PROTECTED]>
Sent: Friday, May 21, 2004 6:06 PM
Subject: MI-L Geological processes affect GIS accuracy?
For example, after a bit of research, I found that the North American Plate
(including myself) is moving away from London (and thus the Greenwich
Meridian) at about 4.4 cm/yr. The plate is also rotating, so that the Y
axis of a projected coordinate system (say, a State Plane Coordinate System)
no longer points due north.
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