Otway, P.M. 1977 Ruapehu site report. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EDS 41 15 p.
Abstract: The survey pattern was established in 1970 April across the crater in the hope of detecting local ground movement associated with changing volcanic activity (NZ Volcanological record 1970). From 1971 until its virtual destruction by the major eruption of 1975 April 24 the pattern consisted of a braced quadrilateral with three intersected stations. This was surveyed by triangulation with scale checks at least once a year. A new pattern comprising a centre point polygon and two intersected stations,. was installed in March 1976, siting the stations on firmer ground where possible and using more durable survey marks than in the previous patterns. For details of the pattern, survey marks and their locations see the Mt Ruapehu Site survey report, 1970-76 (EDS 41) (auth)
