[Imports] Administrative Boundaries and Divisions in Portugal

Martin Koppenhoefer dieterdreist at gmail.com
Tue Apr 14 10:08:41 UTC 2015


2015-04-14 11:38 GMT+02:00 Christoph Hormann <chris_hormann at gmx.de>:

> The problem is over time marker and measured coordinates can differ -
> either through physical movement of the marker or through movement of
> the earth surface relative to the coordinate system used.
>
> If the markers are relatively new it is safe to assume that for
> practical purposes they are the authoritive definition.  If however the
> markers get very old (here in Germany on a municipal level they are
> frequently over a hundred years old) this gets questionable.
>
>

Are you sure about this? I thought that these markers were the authoritive
definition (I believe at least in some cases they are), and that the
coordinates would have to be adjusted to compensate for phenomenons like
plate tectonics.

If it weren't like this, wouldn't you have to move your house after a while
to remain inside the plot ;-) ?

Cheers,
Martin
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