【英语听力】英语高级听力材料： Life in the Freezer

I am at the very center of the great white continent, Antarctica. The South Pole is about half a mile away. For a thousand miles, in all directions, there is nothing but ice. And, in the whole of this continent, which is one and a half times the size of the United States and larger than Europe, there is a year-round population of no more than 800 people. This is the loneliest and the coldest place on earth, the place that is most hostile to life. And yet, in one or two places, it is astonishingly rich.

Penguins come here by the million and endure temperatures of minus 70 degrees centigrade and winds of 120 miles an hour. Other birds fly right to the heart of the continent, even though they have to dig away snow in order to find a place to nest . And here is the nursery for over half the world's seals.

Antarctica is remote from all other continents, surrounded by the vast southern ocean and smothered by a blanket of ice so immense that it contains over three quarters of the world's freshwater.

All life in the Antarctic is dominated by the ice. All but 2% of the continent is covered by it. Its very whiteness reflects back what little heat there is in the sun's feeble rays. And snow, when it falls, remains permanently frozen. So that now, after accumulating for millions of years,

it has formed this gigantic ice cap and the ice beneath my feet is three miles thick.

Submerged beneath it are mountain ranges as high as the Alps, only their summits project through it.

Rivers of ice spill down from the icecap as great glaciers and creep slowly towards the edge of the continent and the sea.

When you get beneath the snout of one of these huge glaciers, you begin to appreciate the immense power and size of the Antarctic ice sheet. The ice here towers 100 feet above me, and the whole front of the glacier is about 2 miles across. But this is a small glacier, the largest glacier in Antarctic and in the world is the Lambert Glacier, and that's 25 miles across. But this is not a place where you want to linger. The glacier moves forward at a rate of about 2/3 of a mile a year and the front-end is continually breaking away to form icebergs. And if one came down now, well, the surge could easily overturn a small boat.

These icefalls disintegrate into brash ice. But when a large chunk of a glacier or an ice sheet breaks away, it floats off as an iceberg. At first these bergs are slab-like. But winds and waves above water and currents

below slowly carve them into the loveliest of the shapes. A large berg can survive for up to ten years before it ultimately breaks up and melts. Only 1/5 of an iceberg is above the surface, the rest is hidden beneath the water. Streams of minute air bubbles released from the melting berg carve grooves in its submerged flanks.

Huge though bergs may be, they are nonetheless usually on the move. But come the winter, sea ice forms around them and locks them solid. As winter progresses, so more and more of the sea freezes, spreading out from the margins of the land like an immense skirt so that, in effect, the continent doubles in size. When the ice reaches its farthest extent, you have to travel hundreds of miles from the edge of the continent before you reach open water.

The annual formation of the sea ice is the greatest seasonal change that takes place on this planet and it completely dominates the lives of Antarctic animals. Practically all of them are directly dependent upon the sea for their food, so year-round access to it is essential for their survival. In the summer, when the sea ice melts, they can reach the islands that were trapped in the ice and eventually the continent itself. But when the ice re-forms, they have to retreat north. So now, in winter, with the sea ice at its fullest extent, it's in the sea that we must look for life.