6 October 2017
Murchison Glacier: more information about the slowly developing rockslope failure that is affecting the hut
Murchison Glacier: more information about the ongoing rockslope failure that is affecting the hut
Earlier this week I posted about the reasoning behind the closure of Murchison Hut, the climbing and skiing refuge located above the Murchison Glacier in Aoraki/Mount Cook National Park in the South Island of New Zealand. To recap, analysis of aerial imagery and satellite images by Dr Pascal Sirguey at the University of Otago and Dr Simon Cox from GNS Science has indicated that the location of the hut has shifted 9 m laterally and 9 m vertically since November 2008, indicating that there is a large-scale rockslope failure occurring beneath the hut. Clearly there is the potential for a major failure event onto Murchison Glacier at some point (without further monitoring this is essentially impossible to predict), such that the hut has had to be closed.
Pascal has very kindly provided some additional images to illustrate the problem, and I post them here with his permission. First, this is a Pleiades high resilution satellite image draped onto a digital terrain model, that shows the location of the hut, the morphology of the slope, and the tension cracks that extend into the snow pack. The scale of the rockslope failure that is developing is clear:-
This image shows the tension cracks that have developed in the snow pack, and the change in location of the Murchison Hut as the rockslope undergoes creep:-
And finally, Pascal has also produced a surface elevation difference model between 2008 and 2017:-
This appears to be a site in which INSAR could very usefully provide insight into the patterns of movement, and any change in rates of creep. Anticipating what will happen next is very hard without this level of analysis; the slope could collapse today or it might still be standing in two decades.