LONGYEARBYEN, Norway, Feb 26, 2008 (AFP) - A vault carved into the Arctic permafrost and filled with samples of the world's most important seeds was inaugurated Tuesday, providing a Noah's Ark of food crops in the event of a global catastrophe.

Aimed at safeguarding biodiversity in the face of climate change, wars and other natural and man-made disasters, the new seed bank has the capacity to hold up to 4.5 million batches, or twice the number of crop varieties believed to exist in the world today.

In sub-freezing temperatures, Kenyan environmentalist and Nobel Peace Prize winner Wangari Maathai and Norwegian Prime Minister Jens Stoltenberg inaugurated the vault by symbolically depositing a box containing grains of rice in one of its three spacious cold chambers.

European Commission President Jose Manuel Barroso, well wrapped up against the cold, looked on.

'This is a frozen garden of Eden, he said.

Norway has assumed the entire six-million-euro (8.9-million-dollar) charge for building the vault in its Arctic archipelago of Svalbard, just some 1,000 kilometres (620 miles) from the North Pole.

'We're pretty far away from the dangers of the world here,' said Cary Fowler, executive director of the Global Crop Diversity Trust and project mastermind.

Traditional Sami chants mixed with African-inspired jazz and child choirs at the opening ceremony.

Overlooking a fjord and adorned for the occasion with a life-size ice sculpture of a polar bear, the vault forms a long trident-shaped tunnel bored deep into the sandstone and limestone.

Metal shelves stacked with airtight bags filled with seed samples line each of the three cold chambers.

Only the entrance juts out of the snow-covered mountainside, emerging as a narrow, triangular portal made of cement and steel, illuminated with artwork made up of mirrors and bits of metal that create a bluish prism visible for miles around.

Under tight security, duplicates of seed samples from 21 seed banks around the world will be stored in the new vault at a constant temperature of minus 18 degrees Celsius (minus 0.4 degrees Fahrenheit). Even if the freezer system fails the permafrost will ensure that temperatures never rise above minus 3.5 degrees Celsius.

Contributions from the other 1,300 seed banks worldwide are expected at a later date.

Protected by high walls of fortified concrete, an armoured door, a sensor alarm and the native polar bears that roam the region, the 'doomsday vault' has been built 130 metres (425 feet) above current sea level.

That puts it high enough to escape flooding if the Greenland and Antarctic ice sheets were to melt entirely, due to global warming.

The concrete cocoon has also been built to withstand nuclear missile attacks or a plunging plane.

The Svalbard Global Seed Vault holds some 268,000 samples. They will remain the property of their countries of origin, which can claim them back if they should disappear from their natural environment.

There are currently more than 200,000 different varieties of rice and wheat in the world, but this diversity is rapidly disappearing due to pests and diseases, climate change and human activities.

In 1949, Chinese farmers grew more than 10,000 different varieties of wheat. Twenty years later, only 1,000 different sorts remained.

Biodiversity is essential because it enables crops to adapt to new conditions, resist diseases, increase their nutritional value and become less dependant on water, according to GCDT.

Twice the size of Belgium and counting just 2,300 inhabitants, the Svalbard archipelago, where ironically no crops grow, is considered the ideal location for the new vault due to its remote location far from civil strife.

phy/National League/po/jj