Internet to reach South Pole

The cable will stretch over the desolate polar plateau

By Dr David Whitehouse BBC News Online science editor

The internet is coming to the South Pole following a decision to lay a fibre-optic cable nearly two thousand kilometres across the polar ice.

It will be one of the most dramatic and challenging engineering tasks ever carried out in Antarctica. It will take years to design and construct, but when finished it will revolutionise communications with the South Pole.

This is going to be a major engineering challenge

Professor Gordon Hamilton, University of Maine

The South Pole is the only permanently inhabited place on Earth that cannot see geosynchronous communication satellites, a fact that severely restricts communication with the base.

The American National Science Foundation has just issued a request for industry to bid to build the trans-Antarctic fibre optic link. It is planned to be in use in 2009.

Present satellite communication with the base is unsatisfactory. It involves using aging satellites that have drifted away from their geostationary orbits into ones that can, for a part of the day at least, be just visible from the South Pole base.

Some satellites in elongated orbits that take them above the pole are also used but they are difficult to work with, say scientists.

Significant engineering problem

Ripples on the plateau

A permanent high-capacity fibre optic cable would solve all these problems. The data link will give high-speed and reliable internet access to the South Pole station. Scientists will be able to transmit data, and researchers in other parts of the world would be able to control Antarctic experiments remotely.

It will also provide straightforward telephone contact for the first time as well as much better medical data about the people there to be monitored.

The cost of the fibre optic cable is put at about $250 million and it is clear that it will be a major technological challenge and engineering feat.

It would run from the South Pole to Concordia, a permanently-manned French station in a region called Dome C. The cable distance is about 1670 kilometres (1040 miles). Concordia is at latitude 75 deg S and is in direct line of sight with geostationary satellites.

The cable will be placed directly on top of the polar plateau. It will have to be laid during the Antarctic's summer months but at the moment engineers do not know how many seasons it would take to lay.

Cable strain

The Polar Plateau is one of the most inhospitable places on Earth. It has an average elevation of 3,000 m (9,900 ft) and the ice is typically 4 km thick. The ice moves a few metres a year but it is quite flat.

In some parts of the traverse crevasses would be a problem. Where there is a risk tractors usually have a radar probe protruding in front of them looking for cracks in the ice.

The cable would be covered with ice where it is expected that it would be subjected to a stable minus 50 deg C.

A significant engineering problem will be how to deal with increased strain in the cable cause by the ice flowing under it and distorting its direct path.

"This is going to be a major problem," Professor Gordon Hamilton of the Department of Earth and Environmental Studies at the University of Maine told BBC News Online.

"The cable will have to stretch as the ice moves. It is important we find a way to allow it to do this that does not freeze and snap the cable."

Just getting the cable to the ice will be a major task.

One plan under consideration calls for tractor traverses from the base on the coast at McMurdo to the pole via the newly established Leverett Glacier route to transport the cable. Alternatively it could be shipped to the French port Durmont d'Urville and traversed to Concordia (1110 km or 690 miles) from there.

It might be necessary to develop new snow tractors and some engineers believe that the current ones, capable of towing 60,000 lbs, are not powerful enough.