November 26, 2012 - ANTARCTICA - At first glance these beautiful images from the Antarctic appear to show 50-ft tall waves that have been instantly frozen as they break. Some people have posted the pictures online, taken by scientist Tony Travouillon at Dumont D'Urville, with a description claiming they are a tsunami wave which was frozen. But although email chains and internet forums back this claim up, what is really pictured is the natural phenomenon of blue ice.
|Hard work: Mr Travouillon travelled to the Antarctic while studying for his PhD from the Australian |
university of New South Wales, between 2001-2004. Image: Tony Travouillon.
These freezing blue towers were created when ice was compressed and the trapped air bubbles were squeezed out. During the summer the surface ice melts and new ice layers compress on top. The ice appears blue because when when light passes through thick ice, blue light is transmitted back out but red light is absorbed. If the bubbles were not compressed they would scatter the light, meaning it would all be reflected back out and it would appear white.
|Imposing: Although this is not, as widely rumoured, a wave frozen while breaking, it is still an incredible|
phenomenon. Image: Tony Travouillon.
Larry Gedney wrote about blue snow and ice on the Alaska Science Forum. He explained: 'It takes an appreciable thickness of pure ice to absorb enough red light so that only the blue is transmitted. You can see the effect in snow at fairly shallow depths because the light is bounced around repeatedly between ice grains, losing a little red at each bounce. 'You can even see a gradation of colour within a hole poked in clean, deep snow. Near the opening, the transmitted light will be yellowish. 'As the depth increases, the corer will pass through yellowish-green, greenish-blue and finally vivid blue. If the hole is deep enough, the colour and light disappear completely when all the light is absorbed.' - Daily Mail.