Amazing green icebergs

四川南江中學(xué) 楊 茜

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海詞積累

1.bubblen.氣泡

2.glacialadj.冰川的

3.compressionn.壓縮

4.accumulatev.積累

5.organicadj.有機(jī)的；器官的

6.impurityn.雜質(zhì)

7.contactn.接觸

Stephen Warren,study leader atthe 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 nobubbles.It was obvious that it was not ordinaryglacialice.Most glacial ice occurs in the shade of white blue.The bluer the ice is,the older it is.Compressionfromaccumulatinglayers 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 thatorganicmaterial 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 organicimpurities.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 incontactwith seawater and takes on a green color when light scatters through them.When icebergs break off the larger ice shelf,they carry this iron-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引導(dǎo)表語從句。

【仿寫】問題是我們?nèi)狈Y金。

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

【點石成金】本句中的It充當(dāng)形式主語，指代后面的that從句。It be obvious/evident that...為固定搭配，意為“……是顯而易見的”。

【仿寫】顯而易見，糟糕的電影會對孩子產(chǎn)生影響。