[fy20]

The article doesn't mention it, but how are the coordinates of property boundaries recorded in South California to take into account the drift?

In my relatively tectonically stable country there is a single coordinate system for the whole country.

I'd imagine you need to record distance to a local landmark or similar? And what happens when there are shifts that end up in roads split in two like in Turkey last year?

https://nationalpost.com/news/world/turkey-syria-earthquake-...

[brendanashworth]

Property boundaries aren't delimited by GPS coordinates, but rather a surveyor's instructions on how to locate the boundary from a set of known landmarks. In most US states, the Public Land Survey System [1] gives "meridians" and "baselines" for each region serving as the regional center. Radiating out, every 6 miles, is a new "township," with its corners serving as the local landmark for property boundaries.

[1] https://en.wikipedia.org/wiki/Public_Land_Survey_System

[topherclay]

But so that means that you could lose land or gain land if enough earth moves and the relative change to the land marks is in your favor or not. But it's just not a big enough of a deal to do it a different way. I do wonder what the most significant occurrence of that is though.

[nobodyknowin]

Surveyors reference monuments on the ground. Since tectonic plates tend to move together then so so short lines and their corners.

It can get complicated on large tracts or lengths, but stuff like rail roads and freeways are composed of many small properties anyway.

[a2800276]

The most significant occurrence is probably land loss due to tidal erosion and/or flooding.

[mavhc]

https://www.xyht.com/surveying/more-on-the-datum-epoch/