On Monday, the Canadian Coast Guard is preparing to send one its research vessels, the Amundsen, through the Northwest Passage with about 40 scientists on board.

Equipped with a remotely operated robot submarine and a sonar system, the ship will undertake a detailed survey of the sea-bed - essential if the waterway is to become more open to commercial shipping.

'Northwest Passage opens' Sailing the passage

Researchers on board also hope to study the changing patterns of the ice - not only the ice that grows and retreats with the seasons but also the far thicker multi-year ice which drifts with the Arctic currents and poses the most serious threat to any vessels.

A British team on board will study the sediment on the sea-bed to hunt for a chemical record of changes in the ice stretching back for the past thousand years - a vital task to help understand the likely rate of change in the future.