‘A Question of’ …Nine Number Picture Boards This nine number picture board is adapted from a template available from Click a number to link to an image Click the image to link to an information page Click the yellow square to link back to the image Click the red square to link back to the picture board Once selected, numbers will change colour

A Question of Glaciation

1 Why is glacial ice blue?

2 How was this feature formed?

3 What can you see? What might this be?

4 This photo was taken in Iceland……. How has this deep, water filled hollow been created?

5 Why is it dangerous to ski on snow covered glaciers?

6 What is the grey material in the foreground? How recently was it deposited?

7 Spot the difference! What might happen next and why?

8 Describe the glacial features of this view!

9 This photo was taken in the Lake District. What feature is hidden from view at X. Why is it hidden? X

Clean, pure ice is not colourless, but slightly blue. The colour, however, is so faint that a small block of ice will look clear. Only very large blocks look blue. Sunlight contains all the colours of the rainbow. Ice absorbs more red and yellow light than blue light. As a result, slightly more blue light passes through a block of ice.

The feature is a roche moutonnee. Ice coming from the right of the photo smoothed the rock through the process of abrasion. On the down ice end of the rock plucking happened where the ice had temporarily adhered and then was pulled away.

The photo shows a cross section of a feature made of stratified sediments. The shape of the cross section and the elongated nature of the feature suggests that it could be an esker. Eskers are fluvioglacial in origin and are formed of deposits laid down in sub glacial streams.

No, this ‘crater’ isn’t volcanic in origin! The deposits are outwash sands and gravels which are down valley of a retreating glacier. A detached block of ice, buried in these deposits, has melted allowing the deposits to ‘cave in’ creating a kettle hole.

Snow on glaciers can hide crevasses. Ropes are needed when walking on glaciers Crevasses occur where ice moves more quickly e.g. near the surface and the centre of the glacier or where the slope over which it is moving gets steeper.

The grey materials form part of a lateral moraine which has been deposited at the side of the glacier. The moraine comprises angular, unsorted material of varying size. It is recently deposited as no vegetation has yet begun to colonise it. Notice how the valley side above the moraine is vegetated. Look also at the freshly scoured rock immediately to the left of the glacier.

The photos of the Glacier du Trient on the Swiss/French border were taken in 1985 and They show the amount of glacial retreat which global warming can cause in just ten years. The one on the right was taken in 2003!

glacier crevasses snout ice falls zone of ablation lateral moraine plucking lateral moraine unsorted, angular moraine scale!

The photo shows the lip of a corrie in the Lake District. Corrie lips develop because erosion is less intense under shallower ice at the front of the corrie. The lip can also be heightened by deposition. Hidden from view in the photo is Stickle Tarn.