在南極冰層下可能藏著一個尚未被證實的巨大峽谷。科學(xué)家們正在進行多種試驗以進一步核實捕集到的數(shù)據(jù)，他們計劃在 2016 年晚些時候公布試驗的結(jié)果。科學(xué)家希望這些試驗?zāi)軒退麄兞私獗鶎訉ξ磥須夂蜃兓姆磻?yīng)。以下是 Jonathan Amos 的報道。

For more than five decades scientists have been trying to draw an accurate map of what lies under the Antarctic ice sheet, which is more than 2.5 miles thick in places. Only a couple of regions remain unexplored, what the experts refer to as the 'Poles of Ignorance'.

One of these is a vast expanse in the east of the continent known as Princess Elizabeth Land. It's now the target of intense study and satellites have detected subtle shapes in the ice surface that suggest there could be a network of canyons hiding down below. If correct, the system would be more than 600 miles long and over 0.5 mile deep. There may be a buried lake as well.

Stewart Jamieson from Durham University led the research: "Knowing what lies beneath the ice sheet is important because we know that the shape of the landscape determines how the ice flows and responds over time. And so we'll be better able to predict how the ice sheet will respond to climate change in the future."

Airplanes are currently flying over Princess Elizabeth Land with sensors that can accurately survey the shape of the rock bed. They should confirm the presence of the canyon system.

詞匯表

accurate 精確的，準確的
unexplored 未勘探的，未探索的
expanse 廣闊的區(qū)域
satellites 衛(wèi)星
subtle 不明顯的，不易察覺的
determines 決定，形成，影響
sensors 傳感器

測驗

請聽報道并回答下列問題。

1. How much of Antarctica is known to scientists?

2. What made scientists think there might be a network of canyons under the surface?

3. Why could the existence of canyons help scientists predict what will happen to the ice sheet?

4. How do sensors find out if there is a canyon beneath the surface?

答案

1. How much or Antarctica is known to scientists?
All of it apart from two regions they call 'Poles of Ignorance'.

2. What made scientists think there might be a network of canyons under the surface?
Satellites have detected subtle shapes in the ice surface suggesting the existence of canyons.

3. Why could the existence of canyons help scientists predict what will happen to the ice sheet? The shape of the landscape determines how the ice flows and responds overtime.

4. How do sensors help find out if there is a canyon beneath the surface?
They survey the shape of the rock bed.