Greenland 4 - glacier
VulcanSpirit
Richard & Alison Brunstrom
Tue 23 Aug 2016 16:37
The glacier above is high up on a mountainside, and again demonstrates how little snow is required before it converts to ice and starts to flow. Note the banding, seen more clearly below:
These bands are like tree rings, each representing one year's snow fall of varying thickness. The tunnel is caused by meltwater.
Below, a glacier is coming off the icecap down towards the sea and the ice waterfall is very obvious - it is about half a kilometre wide. The dirty coloration is gravel and rock ground out by the glacier which is then transported downhill to be dumped at the sides or end, or in the sea.
This is the same glacier, showing that it is in rapid retreat caused by global warming. You can clearly see the bare rock and scree on the hillside left by the melting glacier. Less then forty years ago this whole valley was full of ice up to the 'tide line' that is visible on the hillside, and the glacier was depositing ice directly into the sea. Calculations show that if the entire Greenland icecap melts, which is no longer inconceivable, then global sea level will rise by 7 metres, causing absolute catastrophe to humankind. US Congress please note (fat chance):
Here is a much bigger glacier. Note the lines of stones caused by smaller tributary glaciers merging together
And another, this one still reaching the sea:
The icefall visible here is dropping about 1000m into the sea.
And this is the consequence for boats - the sea full of bits broken off the glacier. These are of various sizes from tiny to very large, and are very hazardous to navigation. The worst are the 'growlers' (another scientific term, so-called because they grind together and cause a growling noise). Growlers can float low in the water, and might be the size of a large car and about as hard. Hitting one of these can easily hole and sink a fibreglass yacht. In the photo below you can see that VS has been picking a careful route through the innocuous-looking ice, with a crew person on the bow armed with a long ice pole to fend off those bits that get in the way.
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