New Zealand’s highest peak Aoraki/Mt Cook is set to have its official height shortened and an Oamaru man is one of the men who did the measuring.
Jim Anderson, 23, of Oamaru company, Survey Waitaki, climbed Aoraki/Mt Cook on November 23 with Dr Nicholas Cullen, a senior geography lecturer at the University of Otago, accompanied by guides Geoff Wayatt and Brian Weedon.
Mr Anderson and Dr Cullen took the GPS measurements which reveal the peak’s height is set to fall by 30 metres.
The official height is listed as 3754 metres above sea level but after Mr Anderson’s and Dr Cullen’s measurements it will be re-assessed as being 3742m at its highest peak.
Mr Anderson, a former pupil at Waitaki Boys’ High School, said they took the latest GPS model, which was pre-programmed, up the mountain.
“We did have plans in place for different conditions. When we got to the top we just pressed it into the ice and pushed the button. We needed to sit for 20 minutes to get accuracy.”
Mr Anderson said from what he had seen, the peak, at its sharpest point, was still losing some of its height,
“It’ll settle sooner or later.”
Describing himself as a “beginner climber,” he said some steep ice climbing to get onto the Linda Shelf was required but the experience had been “pretty cool, pretty surreal”.
“Without the guides I wouldn’t have attempted Mt Cook this year.”
The GPS readings also confirm new aerial photography-based calculations performed by Otago National School of Surveying researcher Dr Pascal Sirguey and student Sebastian Vivero with support from GNS Science and New Zealand Aerial Mapping Ltd (NZAM).
Dr Sirguey, the project leader for the research, said the discrepancy between the old height and the new height could be explained by a two-decades-long reshaping process affecting the remnant of the originally thick ice cap.
“By carefully studying photos taken after the collapse, it appears that there was still a relatively thick ice cap, which was most likely out of balance with the new shape of the summit ridge.
“As a result the ice cap has been subject to erosion over the past 20 years. While the effects of climate change may spring to mind as an explanation, it is probably a case of a simple change in the geomorphology of the mountain.”
The new GPS measurement is only the sixth non-aerial accurate survey of the mountain’s height, with the previous trigonometric measurements being made in 1851, 1879, 1881, 1883 and 1889.
By CHRIS TOBIN