We're walking right up beside the Mueller Glacier
and it's just a fantastic place to see the glacial landforms of the Mount Cook National Park .
What's really noticeable here is how the landscape has been changing through time.
Over the last 150 years or so, the ice has been retreating rapidly.
We can see this because at the edge of the glacier there's a very high moraine wall
and that face shows us how much the glacier has treated since the mid-nineteenth century.
All over the place here, you can see ice sliding off the slopes of the mountains.
We've just come up from Mount Cook Village, it took us a couple of hours,
pretty much straight uphill the whole way
Wow, check it out!
We've just seen a pretty awesome avalanche falling down,
and the sound of it is pretty amazing, kind of like thunder.
There's continual erosion, very rapid erosion
while the mountains themselves are actually being pushed up along the Alpine Fault.
These glaciers build up during the winter when there's plenty of snowfall
and then during summer they have nowhere to go
but over the edge of the cliff faces that you can see around us.
There's a large amount of rock debris
that just gets pushed over the edge with the snow
and is left around littered all over the place.
You can see Aoraki Mount Cook,
it's height is 3,754 metres.
At the moment we're looking at the South Face of the mountain.
Despite it's enormous distance away from us,
it still looks huge compared to it's surrounding environment,
which gives us some idea of the actual enormous size of this mountain.
The Tasman Glacier is the longest glacier in New Zealand.
It runs down just east of Mount Cook and the Main Divide at the Southern Alps.
The upper half of the Tasman Glacier is white snow and ice,
but lower down it is covered by a blanket of rocks, one or two metres deep.
These boulders have either fallen onto the surface from the sides
or been exposed from within the glacier as the surface ice melted away.
The Tasman Glacier is about 29 kilometres long if you include the terminal lake.
This lake is expanding rapidly as the water eats away at the ice,
and is presently about five kilometres long.
You could be in a classroom right now.
We've just arrived at a fantastic viewpoint of Brewster Glacier.
This is just a classic, beautiful small-scale alpine glacier.
So, we've got an accumulation area on the slopes of Mount Brewster.
The lower altitude is warmer,
so the lower part of the glacier melts more rapidly than the upper part.
And you can pretty much find the line of the balance point,
so above the equilibrium line, at the end of the summer, which is now,
you have still got some residual winter snow.
Below the equilibrium line is tending to melt
more than just the last winter's snow.
And that line is represented by the snow line at this time of year.
When we walk on the glacier, we going to have to look out for the crevasses
at the bottom end, that's the tricky bit.
Once we get above those, we'll be sweet, on an easier angle and crunchy ice,
but there's just a few crevasses at beginning that we'll have to negotiate.
So we're about a third of the way up the glacier.
We are measuring the amount of snow melt by the poles that are sticking out of the ground.
When the pole was put in, the top of the pole was at the top of the ice.
It was put in about 5 months ago,
and over the summer it's melted about 5.39 metres.
This year the snow line is very high up the mountain,
whereas typically we would be quite well into the snow line now.
So here we are at pole 12b,
we're about to head back down the glacier,
and it's also showing signs of lots crevasses which is making it quite difficult
to locate the poles on the western side of the glacier.
So that's one metre twenty, five metres twenty total.
This is our second day up on the glacier.
The weather is not half as good as it was the other day, it's a bit foggy.
We have just reached the last pole, number eighteen
which is pretty close to the top of the glacier.
Since November, we've had about five meters twenty of melt.