Thursday, November 21, 2019

Glaciers 3 – Mt. Cook /Aoraki


Into the mountains


If you really want to see the power of nature and particularly the might of ice and snow, Mt. Cook/ Aoraki is a good place to do it. The landscape changes again after Lake Tekapo. There are those dry brown slopes again, which I first noticed on driving up to Arrowtown. I wonder if they turn green in summer, the way Canada does? There is another lake here too – but unlike Lake Tekapo, this one is milky and opaque like an opal, reflecting the fact that it contains much more glacial “rock flour.” This is Lake Pukaki which you follow nearly all the way to Mt. Cook Village. The valley I am driving along has been carved by the combined scouring of at least three glaciers and the mountains on either side are tall enough to make their own weather. When the sun hits them early in the morning you can see the steam rising off the mountain tops as little white clouds which gradually clump together. By mid -afternoon, they have turned into rainclouds ready to come down as either rain or snow.

Lake Pukaki alongside the highway is a different blue

The road follows a typical U- shaped glacial valley. This one has been formed by the conjunction of three glaciers - it's hard to convey the scale

The easiest glacier to get to is the Tasman Glacier. Though like the others, it is now a shadow of its former self, it is in the process of making a large lake which currently sports a few icebergs. The wind is bitterly cold. Since the glacier no longer flows into the small lakes nearby, which used to be called “The Blue Lakes,” and these are now only fed by rainwater, they have turned green instead because they now support algae.  By walking further to Kea Point, you get a glimpse of both the Mueller Glacier and the Hooker Glacier which together have left behind an enormous moraine wall.

The Tasman Glacier - it's that grey horizontal strip in the middle, is melting fast  and has made a large proglacial lake. The glacier is grey because it is carrying a lot of debris which it will push to the sides making a moraine wall, or along the bottom, filling in holes as it goes and making those smooth looking valley floors
Icebergs calve off the glacier face and float in the lake

The once "Blue Lakes" are no longer blue because the Tasman Glacier no longer feeds them and rain water allows algae to grow, making them look green
At Kea Point you can see both the Hooker Glacier which comes in from the west  (top in this picture) and the Mueller Glacier  which comes in from the South (on the left in this case)
This is the massive moraine wall lef t behind at the point where they used to join


There are a number of other glaciers and longer walks here, but given my recent form and the rapidly deteriorating weather, I do an all -weather walk called the Governor’s Bush Walk. Apart from some great views, it was fascinating because it had a great variety of mosses and ferns as well as species such as celery top pines, which we have in Tasmania too. I can’t wait to show them to the lichen and moss experts to see if they are as similar as they look or only distant cousins. The degree of difference is a hint as to how long our two countries have been leading separate lives. My biggest thrill though, apart from seeing the glaciers, was finding a Mt. Cook Buttercup, the only one out so far.

Impressive lichens- the same or similar to those in Tasmania's south west


The magnificent Mt. Cook Buttercup -Ranunculus lyalli - is about 8cm (3.2 inches) across


There'll be no star -gazing tonight. The weather bureau has predicted overnight snow with road closures, but I have already booked and paid to do Milford Sound in a couple of days and I am still a very long way from there.

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