We had issues here in Christchurch after the earthquakes where existing marks were accidentally damaged by well intentioned salvage efforts. Often this was in the areas with the most land movement.
That, plus an initial mis-guided attempt to enforce a coordinate-based cadastral solution gave us many a headache...
Ridgeline, AKA Leon Day is alive and kicking. Chatted with him about three weeks ago. Although he is in Utah, he has been running a fine cow herd within 15 miles of me, here in Kansas. In fact, he just purchased an 80-acre farm here to provide more grazing for his cattle.
I met Leon in Salt Lake City at the national conference. The BIG party at JB Stahl's place. Epic...
Leon is a great guy; always good to chat with! Always enjoyed his posts.
Did you tell him to join our new group; www.RPLS.com?
Will do so the next time we chat.
I imagine that NZ and Maui have similar issues with earthquakes, global movement, local disturbance events. A coordinate system should be based on a Global GPS with a mass of local fixed monuments for areas like these. Simply publishing coordinates isn't going to do it over time. The coordinates will have to be constantly updated, guess who's going to do that.
Probably nobody.
Simply publishing coordinates isn’t going to do it over time. The coordinates will have to be constantly updated, guess who’s going to do that.
The "constantly updating" part is done at two levels. The first level is local surveyors publishing values and associated network & local accuracies when they perform a survey. Not hard to do nowadays with GNSS gear being industry standard, and all the free NGS tools and active control available.
The second level is municipal/governmental entities maintaining and regularly observing the network of "master" local passive marks, such as PLSS monuments, NGS marks, county control, city control, etc.
The new NGS GVX/GTX/GLX observation formats (whatever they end up being called) will be a big help in that regard, as anyone will have a way to publish/share observations in a standardized format, and build up a database that can be adjusted regularly over time, giving a way to quantify or at least observe local movement. (Not that anyone was blocked from doing this already, this will just be a better and "more official" way to do so.)
If an area is prone to local movement, there is a responsibility at both levels to maintain that network and its associated coordinate values. I think a lack of education in the past has contributed to the "oh, there's nothing we can do about it!" mentality, which is really just another way of saying "I don't want to spend any money on this". Maintenance of the parcel fabric and cadastral monumentation is in the public interest, so we better be spending some public money on it.
Seems like a great relationship with the GIS and the Surveying Community there.....GIS maintaining the data, Survey to compile, Interpret/define, and file with the GIS peeps and their chains of influence