According to Dr David Hammond of Cranfield's School of Engineering, a large build up of ice can alter the shape and performance of vital aircraft components.

CNN: SHARE THIS

The changes will be based around the 13th turn, dubbed '50:50', and will involve shaving the ice to change the shape of the turn.

BBC: Whistler Olympic bobsleigh track to be tamed

Many Ukrainians, especially politicians who some joke have more sins than most, step inside ice holes - cut in the shape of a cross - to honour the baptism of Jesus Christ in the Jordan River.

BBC: Pagan holidays in modern Ukraine

The shape of the polar cap indicates that it is composed primarily of water ice, with a volume of 1.2 million cubic kilometres.

BBC: By BBC News Online Science Editor Dr David Whitehouse

An army of snowploughs and maintenance engineers work 24 hours a day to ensure the ice is in tip top shape while the NCC's Ice Safety Committee monitors the ice on an hourly basis.

BBC: Embracing winter in Ottawa