Kluane / Wrangell-St Elias / Glacier Bay / Tatshenshini-Alsek

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NHK World Heritage 100 Series (en anglais)

Texte narratif (en anglais)

Texte narratif (en anglais)

Glaciers flowing into the Sea/Park Reserves in Alaska and Canada (Kulane, Wrangell-St Eilas, Glacier Bay, Tatshenshini-Alsek)

There are four nature reserves with 5,000-metre peaks near the border between Canada and Alaska

Many huge glaciers have been created from those peaks

Glaciers move very slowly at a pace of around ten centimetres a day. Rivers of brilliant blue green water are formed when the sun melts the surface of the glacial ice. Glacial movement creates many deep crevasses. These were made by flowing water. Some are quite deep and reach down to the bottom of the glacier. Glacial ice - on gentle slopes - slows down, evaporates and leaves behind huge piles of sand and dirt. There are ice caves below the surface. They are formed by water flowing beneath the glacier’s surface. Mineral traces contained within the ice affect its colour. Shapes and features found on the walls are formed by wind blowing through the cave. The glacier’s final destination is the ocean. The wall of ice rises to over 60 meters in height.

Sea water erodes the glacial wall and pieces collapse one after another into the sea. The glacial ice transports vital minerals and nutrients from the mountains. They help plankton to thrive and form the basis of a food chain. Sea lions are gathered. The nutrient-rich glacial water has made this area a haven for marine life. This fast-moving dark shadow is a school of herrings looking for zooplankton. The herrings attract humpback whales in summer.

Whales blow bubbles together to make a sort of ‘net’ to encircle the herring school. So-called “bubble-net feeding” is only performed by humpback whales. Scared herrings group closely together and swim into the centre. The whales close ranks, open their mouths and rise out of the water to swallow the herrings in one gulp. The long glacial journey begins 5,000 meters up in the mountains and ends in the ocean. The glaciers have created and maintain a very rich ecosystem which - ultimately - supports the humpback whale.