Amazing green icebergs 奇异的绿色冰川

杨茜

海词积累

1. bubble n. 气泡

2. glacial adj. 冰川的

3. compression n. 压缩

4. accumulate v. 积累

5. organic adj. 有机的;器官的

6. impurity n. 杂质

7. contact n. 接触

Stephen Warren， study leader at the University of Washington， has been on the case of the green icebergs for more than 30 years. He first took samples from one of these green pieces of ice in 1988， near the Amery Ice Shelf of East Antarctica. When he climbed up on that iceberg， the most amazing thing was that this ice had no bubbles. It was obvious that it was not ordinary glacial ice. Most glacial ice occurs in the shade of white blue. The bluer the ice is， the older it is. Compression from accumulating layers of snow pushes air bubbles out of the ice， reducing the scattering of white light. The compressed ice absorbs most of the light except for blue， creating the green seen in the hearts of icebergs and glaciers.

Warren and his team soon found that the green ice came not from glaciers， but from marine ice.

At first， the team thought that organic material stuck in the marine ice caused the green color. But further research showed that the green marine ice didn't have a higher-than-usual amount of organic impurities. Now， a new study finds that a different sort of impurity may be the root cause of the green ice. Warren and his colleagues report that the marine ice at the bottom of the Amery Ice Shelf has 500 times more iron than the glacial ice above.

This iron comes from the rocks under the Antarctic Ice Sheet， which are turned into a fine powder as glaciers move over them. The ice is in contact with seawater and takes on a green color when light scatters through them. When icebergs break off the larger ice shelf， they carry this iron？鄄rich ice with them. It's like taking a package to the post office. The iceberg can deliver this iron out into the ocean far away， and then melt and deliver it to other living things that can use it as a nutrient.

Reading Check

1. Why did Warren feel surprised on the top of an iceberg in 1988？

A.The iceberg was quite ordinary.

B.The iceberg had no bubbles.

C.The iceberg looked pure white in the heart.

D.The iceberg occurred in the shade of white blue.

2. What actually contributes to the green color of some Antarctic icebergs？

A.Compression from seawater.

B.Organic material of marine ice.

C.Reflection of iceberg light.

D.Iron from the rocks under the Antarctic Ice Sheet.

3. What can the “package” mentioned in the last paragraph do？

A.Turn iron into powder.

B.Break off large ice shelf.

C.Offer living things nutrients.

D.Keep us informed of icebergs.

Language Study

Sentences for writing

1. The most amazing thing was that this ice had no bubbles.

【點石成金】本句中的that 引导表语从句。

【仿写】问题是我们缺乏资金。

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2. It was obvious that it was not ordinary glacial ice.

【点石成金】本句中的It充当形式主语，指代后面的that从句。It be obvious/evident that...为固定搭配，意为“……是显而易见的”。

【仿写】显而易见，糟糕的电影会对孩子产生影响。