Blue Ice and Green Minerals: a trip to Fox Glacier

By Nick

The Fox Glacier, up close and personal

No doubt you’ve seen a video of that Glacier in Argentina that sheds icebergs every minute or two. More normal glaciers are much more stable, and don’t really do anything much. But there’s a tangible sense of the inevitable passage of time. A chance to take photos so that you can compare how it looks in years past and future. And a slight forlorn feeling as to the future of the glacier in this ever warming world. It’s a bit like visiting small babies.

Down in the south-west of New Zealand’s South Island are a pair of glaciers, Fox and Franz Joseph. A chance to see a real glacier up close and personal. Perhaps my overwhelming feeling was just how blue the ice is. I’ve been told how blue glacier ice is, and of course I’ve seen pictures. But glaciers really are blue. And dirty. Lots of rocks and rock dust littering the surface made the sides and tops a dark grey. As did the light and dark annual layers you could see in the ice. In fact, I think the only colour you couldn’t describe the glacier ice as is white.

To add to the ethereal palette, the seemingly grey valley wall rocks, scoured smooth by the former passage of the glacier, were, on closer inspection of the moraines, scree slopes and gravels, actually green. The minerals chlorite and epidote, products of the metamorphism of sedimentary rocks, since thrust up by the alpine fault gave a glistening green colour to the rocks. Geologists gathered in the light mist to discuss the history of the rocks and the conditions that they must have endured (both the geologists and the rocks).

The rate of retreat of the glacier was remarkable compared to photos taken by one of our party just two years previously. One thing I learnt was that the position of the glacier each year is actually determined by the amount of snow fall some ten years previously. Thicker and thinner sections of ice make their way slowly down the valley, moving the leading edge of the glacier backwards and forwards, a decade long delayed response to the El Nino/La Nina cycle. The overall trend though is unfortunately backwards. The Fox Glacier is a sight to behold, albeit one which will continue to shrink back up the river valley.

There was a disappointing lack of mints though.

One response to “Blue Ice and Green Minerals: a trip to Fox Glacier

  1. Hi, thanks for sharing.

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