PLANET EARTH Ice Worlds

In the depths something stirs... Humpback whales（驼背鲸）. They have travelled over 5000 miles to reach these waters. The whales are harvesting krill shrimp（磷虾） like creatures that begin to swarm here as soon as the ice retreats. Diving into the heart of the swarm teams of whales spiral around each other in close coordination. Now they turn and blasting air from their blowholes（呼吸孔，就是通常以为的顶端的喷气喷水的那个地方） and ascend towards their prey. The krill becomes concentrated as the spiraling net of bubbles draws inwards（气泡网螺旋向内）. The team of whales work around the clock for the bloom is short lived.



Summer is already fading and the whales will soon be forced north as winter returns. The sun's influence diminishes and the ocean starts to freeze. The greatest seasonal change on our planet is underway. The ice grows at an extraordinary rate advancing two and a half miles a day. In a matter of（大约） weeks the continent effectively doubles in size.



Life flees from Antarctica... but one creature is just arriving. Every winter Emperor penguins leave the comfort of their ocean home and begin a remarkable journey. They head towards their breeding grounds almost a hundred miles inland. Eventually the emperor penguins reach the place where they were hatched an area sheltered by icebergs trapped in the frozen ocean. Here they will raise the next generation but first each must find a mate.