Page 7 - living-ice

PHOTO: Rudi Cayers
The Arctic Ocean
The water surrounding the North Pole is called the Arctic Ocean. This is a circular basin surrounded by the land masses of Eurasia, North America and Greenland, and the archipelagos of Svalbard and Novaya Zemlya. The Arctic Ocean is almost completely covered by dense pack ice in winter, but in summer a lot of this ice melts. Much of the sea ice is continually drifting. The closer one gets to the open sea the smaller and more broken up these ice oes are. The rapid melting of ice in summer creates a broad belt of small ice oes that drift rapidly. This belt forms the zone between the densely-packed sea ice and the open sea.
The extreme changes in climate and light from summer to winter make the Arctic Ocean unique. The ice extent is extremely seasonal, reaching its maximum extent in spring and minimum extent in autumn. In the past, a large part of the Arctic Ocean was covered by multi-year sea ice that had survived at least one melting cycle. Now most sea ice melts in the summer. The area covered by ice only in winter is referred to as the seasonal ice zone. Since the difference between winter and summer ice cover has increased so dramatically in recent years, this seasonal ice zone now covers an enormous area of two-thirds of the entire Arctic Ocean surface. This is equivalent to roughly the size of Europe. The main reason for this shift from old and thick ice to short-lived and thin ice is global warming. Nowhere on earth are the effects of global warming greater and clearer than in the Arctic.