Hull, A.G. 1978 Trig site stability survey report, Napier earth deformation survey. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EDS 51 39 p.
Abstract: Part of the Earth Deformation Studies Programme is the reobservation of existing survey networks. To ensure that any observed movements are the result of crustal deformation, it must be certain that trig stations are not moving independently of the surrounding land. Consequently all trig stations must be assessed for foundation stability. This report is the result of the observation of 7 first order and 13 second order trig stations comprising part of the proposed Napier earth Deformation Survey. It describes the topographical and geological setting of trig stations, with the assessment of their stability and any upgrading or relocation required. Not all sites were visited, 33 stations are reported from aerial photograph interpretation and a previous NZ Geological Survey site report (Berryman and Guy, 1978). At 7 localities both Lands and Survey and NZ Geological Survey marks are present. Where the stability of the NZ Geological survey mark is better than the first order Lands and Survey mark, it is recommended that the NZ Geological Survey mark is used. This avoids the need to upgrade existing Lands and Survey marks and provides a more stable mark. Where lines of site are obscured by this change of location, it is recommended that the Lands and Survey mark be occupied and tied to the more stable NZ Geological Survey mark. (auth)
