Climate

Today we flew up to our highest planned drill site on Mount Hutton. Yulan stayed behind, and with us instead were Tom McRae and Ron Madden from TV1. Because of the prospect of poor weather forecasted for tomorrow, we had decided to do a rapid reconnaissance drill only. If the results proved to be good we would come back with a better weather window to drill deeper. Mount Hutton is relatively remote – on the eastern side of the Park in the Liebig Range. We hoped that with the higher elevation and the location some distance away from the main divide, we would get a better preserved and longer climate record. Our radar survey showed a depth of only 50 metres of ice, but perhaps 50 metres of thinner layers would be as good as 100 metres of thicker ice further to the West (such as on Annette Plateau). The flight up was spectacular the icy clouds producing a nice sundog spectrum . Mount Hutton has a small glacier on top. It has a ridge running straight up the middle, and our drill site was about 3/4 of the way up the ridge from our landing site at the bottom. I went a head with Uwe to find our spot and start digging in. The winter snow was only 1.5 metres deep here (as opposed to 4 metres on Annette Plateau)Tom and Ron were interested in what we were attempting, asked lots of questions and interviewed us for their news programme. When they left at about 1pm, Dan went down with them, leaving Uwe, Xinsheng and myself. By 4pm we finished drilling having got down to 10 metres, with very nice, bubbly glacier ice immediately below the top surface snow. The heli arrived and flew away with the net load of gear, then returned half an hour later to pick us up. The evening light was beautiful across the big peaks of the Southern Alps.

Dan and I got up early and each went of for a walk around the glacier. I climbed up Mount Annette and then returned through the wind scoop. The plane arrived and by the time it was fully packed there was no room to fit both of us in! I decided I would be happy to walk down to the village. I set out with a pair of bamboo poles and snow shoes. The way down involved crossing some steep slopes, with wonderful views across the Mueller glacier and I was happy when I reached the valley floor where Uwe had come to pick me up. The photo shows the tracks I followed across the mountainside.

Yesterday we dragged the drill and equipment across the glacier, set it up in a newly dug pit and made a protective wall of snow blocks. After 10 metres we came to wet ice and decided there was no point to continue. Back to the drawing board.After having further close looks at the radar images, we decided to have a third attempt higher up the glacier. Today we again moved all the gear to a new drill site. This time we hit wet ice only 4 metres down. Our first 45 metre core was starting to look like a lucky strike compared to this! We decided to strike camp. Within a few hours most of the gear was packed and stacked in heaps. Later in the afternoon 3 helicopter loads got most of the gear away, as well as Uwe, Xinsheng and Yulan. Dan and I stayed on, doing some final sorting and planning to fly out by plane at 11 in the morning.

After yesterdays progress, today’s was disappointing. During the night, water had seeped into the drill hole and other technical issues slowed down the drilling. Then from about 45 metres below the surface we pulled up an ice core that was dripping with water. We must have drilled into a water conduit in the glacier. We lowered a weighted cord down the borehole and when we pulled it back up about 13 metres of it was wet. The water had flooded our drill hole. This was very disappointing. We discussed what to do and decided that the next day we would set the drill up for another attempt about 300 metres away, near to an interesting wind scoop on the side of the glacier. This feature is about 70 metres deep and several hundred metres long, where the strong winds have scooped out the snow and ice all around the side of the peak of Mount Annette.

By 9am all was set for drilling to start Having dug a pit about 2 metres deep into the snow to find a hard layer for the drill to stand on securely, we were still another 2 metres from the previous summer surface of the glacier that was now under a total of 4 metres of this winter’s snow.This is how we drill the ice cores: It is fascinating to watch the way Xinsheng operates his drill. First he makes sure it is aiming exactly straight down by holding onto the motor while the drill barrel cuts its way down into the ice. Initially the rotating core barrel is at the surface, but soon he will hold onto the wire line to feel how the drill is cutting down deep in the drill hole. After a certain distance has been drilled – usually just less than 1 metre, the power gauge on the control box shows that the motor is starting to struggle. Xinsheng then tells Yulan to stop the motor, gives the wire a few sharp tugs to break off the core from the ice below, and then Yulan switches on the winch motor to haul the drill up to the surface. The drill barrel is then detached from the motor, and the ice core, along with a mass of ‘chips’ is pushed out of the barrel onto a core tray. One of us measures the core, matches it with the previous section and cuts it to fit it into the 1 metre ‘layflat’ polythene bag that is already prepared and labelled. The core then goes into an ice core box, with all necessary details noted into the field notebook. There are quite a few technical issues that can slow down the drilling process. The quality of the ice can change, and sometimes faults develop with the drill itself. Xinsheng has an amazing ability to remedy these pitfalls – I was impressed watching his resourcefulness as we progressedSo here on Annette Plateau, our first drilling was going well. There were several dust layers in the core at intervals, most likely suggesting summer layers where melting at the surface had concentrated wind blown dust into a distinct deposit. Progress was good. Apart from a short wet layer at 29 metres, the ice was looking cold and bubbly – good quality glacier ice. We continued drilling until 11 pm by which time we had reached about 40 metres below the surface.

By 8am we were all at the airport loading a huge pile of supplies into a sling net for the helicopter to take up to the Annette Plateau. I went up with the first flight with the job of pointing out our chosen drilling location to our pilot Brendan. Unfortunately the GPS co-ordinates were wrong (!) so I had to make a best guess using the footprints of the radar traverses which were still visible. After landing and unloading the net, the heli flew away leaving me with the mountains, the glacier, the sun and the silence – for a short time at least. I started to sort out the gear and soon two planes landed beside me, with the rest of the team and more gear on board. After we had unloaded, a short walk around the area showed that my judgement of the drill location was about 80 metres out so we had to drag the gear pile to the correct position.   The day was spent putting up the drill shelter and digging a snow pit under it’s protective cover. We also put up the tents and organised the equipment to start drilling the next day. It was a beautiful clear night when we turned in, with a bracing minus 12 degrees C discouraging prolonged stargazing….

 Today I jumped into a helicopter with Lawrence Kees and Alice Doughty from Victoria University Wellington. We flew up to the Annette Plateau to do some further radar work. I took the opportunity to test the snow conditions for securing tents and see if there were any possible snow caving sites nearby as a back-up. I dug a snow pit about two metres deep and then used my avalanche probe to feel deeper down. It was mainly soft snow with a few slightly denser layers. At about 4 metres deep I could feel the hard ice of the last summer surface. This means that in order to secure our tents against very strong winds we will have to use lots of ‘deadmen’ – large sacks filled with snow and buried to act as anchors. Tent pegs – even snow stakes would be no good in these conditions. This Photo shows Lawrence and Alice setting of to traverse up and down to complete the radar survey, I took a walk around the edge of the glacier to see if there were any suitable sites for snow caving. I was looking for steep angled snow slopes of drifted snow at least 2.5 – 3m deep. By probing around I found a good spot that was within about 2 – 300 metres of our intended drill location. This was great – it was a reassuring safety back up for our accommodation on the mountain. The helicopter returned to collect us at about 1 o’clock. It was carrying a sling load off ice core boxes. Uwe had obviously decided that the weather forecast was good enough to go ahead with the drilling from tomorrow. The short flight back to the airport gave us a spectacular view of Mount Cook seen up the Hooker Valley. When I got back to the Lodge, the team told me about the improved weather forecast for the next week. Action Stations for tomorrow! Paul left as planned to go back home to the US, leaving five of us: Yulan, Xinsheng Dan, Uwe and myself to make up the drill team. If all goes according to plan, we will be up on the Annette Plateau for several days and I will tell you how we get on when we are back down in civilisation again.

Today the weather was an improvement over the last few days. There was a cold southerly at first after which the skies cleared. We went for a walk up the Hooker Valley, past the Mueller Lake, and up to the Hooker Glacier lake. The mountains on all sides are spectacular, with Mount Cook dominating the view in the background. At the Hooker Glacier lake we could see the terminal face of the glacier. You can see curved rock layers in the ice where it is breaking off into the lake. There are quite a few of these proglacial lakes in the area, and all of them are expanding rapidly these days. The water undercuts the ice face until large pieces break off and float away as icebergs. The remaining ice below water level then becomes buoyant and breaks off in huge chunks which then pop up to the surface from below. Check out here to see a video we took of this happening back in February! On the way back to the car park, we saw a couple of huge avalanches crashing down the East Face of Mount Sefton. These were the biggest avalanches I have ever seen, and must have involved thousands of tonnes of ice coming of the vertical ice cliffs. I even managed to capture one of the avalanches on video:

 Today we finally drove over to Mount Cook village. Lawrence Kees The large living area of our base at the New Zealand Alpine Club’s Unwin lodge was soon covered with STUFF. The white boxes are for storing ice cores to keep them frozen as they get transported down from the mountain and into a freezer or freezer truck. They are very useful for storage of gear and food that has to be taken up as you can see in the pic. (photo 4) A few sundry items in the gear list include: Flood lamps A generator for the electric drill and emergency backup generator Hand warmers, Radios and satellite phones, Snow shovels, snow stakes, ice axes, harnesses and ropes, 5 Tents (including spares) , sleeping bags, sleeping mats, Bamboo flags for marking routes in blizzards And lots and lots of food The weather forecast for tomorrow looks possible for flying, Lawrence, Paul and myself are all set to get going early with the radar and enough gear to stay put if we get stuck in bad weather. – a basic and highly possible situation with the unstable conditions of recent weeks