elidana
commented
8 years ago Hi @pdenys162 ,
many thanks for taking care of our GUNR cGPS site, this is really appreciated.
We were aware of the problem since the end of 2014, and if you look at the site description for GUNR on our Delta database, you can find this warning:
ON LARGE LANDSLIDE. Analysis of the data shows GUNR is moving atypically for regional tectonics and compared to nearby stations (eg MTPR). Affected by large landslide (also scarp visible to North).
Our time series show the same problem you pointed out with your processing, as can be seen by comparing GUNR vertical to MTPR (Mt. Prince), located ~8 km NW of GUNR:
Unfortunately we were (and currently are) unable to relocate the site due to budget limitations, so we decided to leave the site operating, also because our scientists from the Landscape Department have some interest in monitoring the landslide.
We really appreciate your offer to help and hopefully we will be able to relocate or build a new site in the future. In that case, we will surely get in touch with you, and your proposed sites will be our starting point for any site selection.
Kind regards,
Elisabetta
The cGPS site GUNR (West Coast) appears to be located on a landside. The site is unstable and the velocity is not representative of the region e.g. MTPR. (The vertical velocity is >-7 mm/yr). Hence it is not a good site from a science (or anything else) perspective. I would like to suggest that the site is moved to a location that would be more beneficial.
Time Series and horizontal plots in attached files:
GUNR.pdf GUNR_hz.pdf
Some time ago, we did a recce to find sites to extend the SAGENZ profile north and south of the existing east-west profile (QUAR-MTJO) with the view of determining if the vertical velocities are increasing/decreasing north or south. We visited four sites, which could be potential sites.
Name of Conservation Area Legal Status Area Architect Creek H36 6331 or 6230 Westland National Park Cook River H36 GS 6337 Westland National Park/Stewardship land Mt Hermann G36 GS4320-4420 Stewardship land Bannock G36 GS4122 Stewardship land
Unfortunately the grid references (grid square) are in terms of NZMG. However, these sites have radio comms to either quarry (QUAR) or another of the SAGENZ cGPS site.
I would propose that we remove GUNR and re-establish it in, say, the area identified near the cook river. I was wondering if this would be worthwhile investigating. We would be happy to be involved.
Paul Denys School of Surveying