Record-breaking amounts of ice-free water have deprived the Arctic of more of its natural "sunscreen" than ever in recent summers. The effect is so pronounced that sea surface temperatures rose to 5 C above average in one place this year, a high never before observed, says the oceanographer who has compiled the first-ever look at average sea surface temperatures for the region.

The International Ice Charting Working Group predicts more marine transportation in the Arctic as sea ice continues to diminish and warns of "significant hazards to navigation," according to a statement released yesterday.

Arctic sea ice during the 2007 melt season plummeted to the lowest levels since satellite measurements began in 1979, according to researchers at the University of Colorado at Boulder's National Snow and Ice Data Center.

In 2001, Russia first claimed its right to the territory, but the UN demanded more evidence.Moscow has repeatedly argued that the Lomonosov Ridge is part of its land mass - and now the Natural Resources Ministry believes it has the proof.

Global warming is melting the Arctic at an alarming pace. This summer the Arctic ice cover was the smallest ever recorded. As a result, a host of countries are seeking to drill for the oil and gas once protected by ice.

The area of floating ice in the Arctic has shrunk more this summer than previous years since satellite tracking began in 1979 and it reached a record level a month before the annual ice pullback typically peaks.

Sediment cores retrieved from the Arctic's deep-sea floor by the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX) have provided long-absent data to scientists who report new findings in the June 21 issue of Nature. A team of ACEX researchers report that the Arctic Ocean changed from a landlocked body of water through a poorly oxygenated 'estuarine sea' phase to a fully oxygenated ocean at 17.5 million years ago during the latter part of the early Miocene era.