Aoraki Mount Cook being the biggest, most complex and highest mountain in the country,
represents one of the most interesting.
With it's eight ridges or so, it's multiple faces, it's big, it's complex and it's challenging.
It's a special place.
Early in November 1991, Brian Whedon and I decided that we were going to
do an East face, climb and we sit off in early December having planned the trip.
We climbed the east face in about 10 hours,
Seven days later the whole of the east face fell off
and fifty million tons of rock roared down into the Tasman Valley, filling it with mud and ice.
So we had actually done the last ascent of the old height of the mountain.
In December 1991 a big rock avalanche came down Mount Cook and took the summit off.
At the time there was a bit of a debate as to how much came down the mountain
and how much the top was reduced by.
The figure eventually settled to ten metres less, making the height of Aoraki 3,754 metres.
Our model for some reason differed from that height by a substantial amount.
Since the big avalanche there's been an estimate of the change in height
but we're here to determine whether they estimate is correct or not.
We're presently at Plateau Hut which is at about 2,200 metres
and this was the first step in our trip to serve a Mount Cook.
The most important instruments for us are the two GPS's - the trimble R10's.
We will use those to survey the top of Mount Cook.
This is a University of Otago and GNS funded trip
so we've had to be really careful about the safety measures.
We've got two guides working with us
and we're going to use the standard protocol which is one guide per client so there will be a party of four.
As preparation for the climb we did some snow safety this afternoon.
So you are roped together and you need to have fixed points and anchors
you use snow snakes and other things to protect yourself.
So we ended up waking up at about midnight. Other climbers were busy getting ready to go
we did the same, and then I think we lift the hut at about 1am.
Walking through that darkness you follow just a small train of head torches
porches and that's your only kind of reference point, because it's otherwise completely dark.
One thing that happened to us was that there's a large shrund at the top of the linda
which was basically a big crevasse and it was really difficult to pass through,
there was only one little small section that had a bridge but it was almost vertical.
But we managed to pass through that and then it was not too far after that time
that the Sun really started to appear, and that moment of brilliance
when the Sun comes up and suddenly you realize how high you are
and that vista of the New Zealand landscape suddenly appears.
It's just a brilliant feeling. it's beautiful.
There's certainly plenty of ice falls in a place like this and so they're the uncertainty.
So as you pass up through the linda have to be fairly careful,
there's a particular point where you do pass under some ice cliffs.
At that point you really want to just keep moving quite quickly and minimise the risk.
We were fairly high, not too far away from the summit rocks,
and at that point we really got into pitching where you really have to
belay and move through a rock band that separates you from the summit.
It was beautiful conditions and the sun had come out so we warmed ourselves up,
and it was just really enjoyable climbing on some little steep rock bands.
a lot of it's quite poor quality so you have to be fairly careful about what you hold
because falling off and you don't want those rocks to fall on people below you.
But there are sections which are actually really nice rock as well.
Then the last section to the summit was really straightforward.
The summer itself is reformed and it was quite a nice area to sit down and
we could really place the GPS's on the location that we wanted to be.
We had some stakes that allowed us to drive a pole into the ice and
then we set the GPS's on that and they're simply pre-programmed
so it's really just a matter of pushing go, and then the critical thing there
was just to maintain a static survey, for us to be there at least 20 minutes.
Given the difficulty of climbing Mount Cook to actually get to the summit and do what we were supposed to do,
it was a really great feeling and to take those unique measurements was an achievement I think.
Of course when you get to the top it's only halfway, so the deceit is something that you have to
be fairly careful with. It was uneventful, the abseils went well,
we did that as a party of four with double ropes which allowed us to pass through that section fairly quickly.
The snow had softened significantly over the linda shelf so that was quite an easy walk.
The the climb itself was a total of just over 18 hours.
10 hours to the top and we probably spent about 45 minutes almost an hour at the top
doing the measurements, and then back down and so I think we were just over 18 hours.
The GPS measurements that we took got a height of 3,719 metres,
however the very highest point of the mountain is a short distance along the
knife-edge summit ridge. our GPS measurements were therefore used to
calibrate a 3D computer model of the mountain made from aerial photography.
We were then able to calculate the height of the highest point of Aoraki Mount Cook
which now stands at 3,724 metres.
This is 40 meters lower than the summit height prior to the 1991 rock avalanche.
We climb mountains for various reasons, various personal reasons
but we also climb and look at our landscapes for understanding our world much better,
and I think this contributes to understanding our world.