Big Trip

Treated ourselves to a lie-in this morning. Took a leisurely drive up to Mt Cook village at the head of the valley. It's dominated by a large hotel, the Hermitage, which appears to be made mostly of something sort of dark charcoal grey, and the towering mountains all around, still with their icefalls lingering quite a long way down.
After lunch, took the Glacier Explorers trip out to see the Tasman Glacier. At 18km, it's New Zealand's longest glacier, and comes down the Tasman Valley right next to Mount Cook. We had a 5 minute bus ride and a 20 minute walk to the top of the terminal moraine wall left by the last major advance of the glacier about 50 years ago. On the other side was a very light grey lake, and an awful lot of dark grey rock. On the lake were some small yellow boats (Erin was very worried about falling out of them). Once in the boats, we hooned around the lake, which was only about 3 deg C, and that, we learned, is the warm layer at the top. Actually, the lake's about 200m deep and the glacier goes all the way to the bottom, which makes it pretty cold. There were quite a few small icebergs floating around, and some grounded, so we motored up to one and got out for a walk around. They're an odd miixture of rock & ice, which makes them very black & white, unlike me.
The rest of the trip consisted of more doodling round the lake, which is a fair size, inspecting the terminal walls of the glacier and the icebergs that have broken away and are visibly thawing. The glacier is filthy. None of your crystal clear ice here. It's mixed with liberal amounts of dark grey rock, which makes the whole thing look pretty black and unattractive from a distance. Close up it's much more fascinating because the whole thing's animated. There are drips & trickles, rivulets running off the top, small rock falls into the water, and the distinct feeling that at any moment, a large lump of either ice or rock could crash into the water around you. The other thing is that the sides of the valley are huge lateral moraine walls, about 50m above where the glacier is now. Those represent the height of the glacier at its last push, a few decades ago, and they're made of crumbled rocks that have been brought down the valley by the movement of the glacier. The whole thing was completely fascinated, and Max & Erin particularly enjoyed being able to handle & taste lumps of glacier. We were lucky enough to have superb weather for the trip, and also excellent views of Mt Cook clear of cloud, as well as the movement of the cloud forms over the top.
Oh, and of course the reason the water is grey is that it's full of rock flour. The reason that this lake is grey and Pukaki is turquoise is that the lower lake is a mixture of glacial water and fresh water from the hills, which changes the proportion of rock flour and therefore the diffraction of the sunlight.