ANTARCTICA : Beautiful it may be, but the Brighton Rock effect in this iceberg would have been created from dirt, animal excrement and fragments of dead bodies.

The iceberg was seen from a research ship sailing in the Southern Ocean about 1,700 miles (2,700 kilometres) south of Cape Town and 650 miles north of the Antarctic continental shelf.

Keith Makinson, of the British Antarctic Survey, said that icebergs that seemed to show stripes were quite common in southern waters, but it was the first time that he had seen brown stripes. They are believed to be created when ice crystals form under the water and, in a process described as “inverted snow”, rise to stick to the bottom of the ice shelf. As the ice crystals form a new layer at the bottom of the ice shelf, which later fragments to float away as icebergs, tiny particles of organic matter are trapped.

Parts of dead marine creatures such as krill form much of the trapped material and have the effect of creating coloured stripes, mainly blues and greens, in icebergs. Dr Makinson said that the brown stripes in this example were likely to have been formed from sediment washing underneath the ice shelf.

Times recommends

• Energy-saving ideas from switched-on professor
• Rooks are as clever with tools as chimpanzees
• Burping of the lambs blows roast off menu