When I saw this the first thing I came to mind is what it would do to the property lines:
Here's the video:
I had to watch the video about 10 times before my brain could process what I was looking at.
I can't imagine being in the middle of a survey and having to figure out how to continue.
If the previous surveyor looked as far into the future as he did into the past, he would have tied the parcel to GRS80 (Everest 1830 in Burma), so you'd just locate the post earthquake positions of the found monumentation, then set new monuments at the pre-earthquake position.
you'd just locate the post earthquake positions of the found monumentation, then set new monuments at the pre-earthquake position.
California, which knows a thing or two about earthquakes and property lines, has a statute -- the Cullen Earthquake Act (Code of Civil Procedure § 751.50-751.65) -- that treats sudden and catastrophic land movement similar to the way the law treats avulsive movement of a stream: the old boundaries yield to the new reality. Under the statute, the court determines an equitable redistribution of the land among the affected owners, and the result is binding upon all. So the previous ECEF coordinates of the old corner monuments are pretty much irrelevant.
@murphy Living in southern New Zealand I have some personal experience in this matter.
We tried what you are suggesting, and it does not work in the real world.
We ended up with boundaries passing through buildings, party walls that no longer included the wall, encroachments into the road reserve, occupation that was no longer relevant and so on. It was a right clusterf*ck.
Yes, New Zealand has a cadastre from which coordinates could be pulled and a doctrine of erosion/evulsion - but after about two or three years of confusion we went back to the old 'monuments rule' method.
I was under the impression that a long slow accretion or reliction would allow the boundary to follow a stream or other natural boundary but an avulsive movement of the same would not alter the original boundaries. Are you saying that in CA, real property owners with title to the centerline of a stream would have their shared boundary altered if said stream formed a new channel after a single flash flooding event?
Also, if you had coordinates for the old boundary, there's always a possibility that it could be of some assistance in sorting out the mess if for no other reason than to visualize the absurdity of holding the original locations.
I'll say it again, you are throwing away valuable information when you're using GNSS and not tying your parcels and projects to Earth. Think of it this way, all you have to do is put two coordinate pairs on your plat, a copy and paste from a csv. If you can accurately foresee that surveyors one hundred years from now will have no need for another layer of redundancy, then you're right, it's a waste of time placing parcels on Earth. I lack your hubris in regard to predictions of the future and find the cost of tying parcels to Earth with metadata very cheap insurance.
I'm mostly being flippant here, but are you saying that there's no value in New Zealand to tie a boundary to a geodetic datum? If so, at what point in the future, if any, would you predict that geodetic ties will be valuable enough to be included in boundary or control surveys?
I'm mostly being flippant here, but are you saying that there's no value in New Zealand to tie a boundary to a geodetic datum?
Actually the opposite, every cadastral survey here must be tied to an official datum.
But we recognise that the earth is not fixed, that things move, and that rate of movement is significant, measurable, and not even across the whole country.
The earth is a big ball of jelly.
More information is better, so when it makes sense to put a survey on the grid, I do it. But most of my urban/suburban jobs are done with a total station only, so I mostly don't bother with GNSS on those. (As it happens, the lot survey I finished this morning required me to run several traverse legs to get where I could see the back corners, so I tied the control with RTK as a blunder check.)