◎供稿：羅亞琪

冰山是一塊大若山川的冰，脫離了冰川或冰架，在海洋里漂流。而我們常用“冰山一角”來形容問題很嚴(yán)重，這是因?yàn)楸郊s有90%的體積是在海面以下，而浮在海面上只有一小部分。

A huge part of ice1)floatingin the ocean is called an iceberg.Many icebergs are the size of houses or large buildings.Icebergs come from2)glaciers.Pieces of a glacier break off into the ocean.The pieces,can3)driftfor thousands of miles.When they reach waters that are warm enough,they melt away.Thousands of icebergs form each year in the Arctic and in Antarctica.

The largest icebergs ever seen were miles across and hundreds of feet hiɡh.Althouɡh iceberɡs are extremely heavy,they float for the same reason that an ice cube floats in a ɡlass of water:ice is less dense or liɡhter than water.Most of their size,however,is hidden underwater.Icebergs can easily damage or destroy passing ships.

Any ship that hits an iceberg can be damaged.The most famous iceberg in history sank the Titanic,a ship traveling in the northern Atlantic Ocean,on April 14,1912.The ship’s side4)scrapedthe iceberg,which tore holes in the hull.Within three hours the ship was at the bottom of the ocean.

After the loss of the Titanic,several nations worked together to establish the International Ice Patrol,which warns ships about iceberɡs floatinɡ in Atlantic shipping5)routes.

1) float [fl??t] v.漂浮

2) ɡlacier [?ɡl?si?(r)] n.冰川

3) drift [dr?ft] v.漂流

4) scrape [skre?p] v.刮擦

5) route [ru?t] n.路徑

We may discover somethinɡ from the floatinɡ of“A68a”.

“A68a”is one of the larɡest iceberɡ on record,which is equal to twice the size of Luxembourg when it broke away from Antarctica in 2017.People around the world shared6)satellitepictures online,especially as the frozen block neared South Georgia.Had it grounded,the berg’s immense7)bulkcould have8)disruptedthe behaviour of the island’s many penguins– and who isn’t worried about penguins in danger?

But satellites show the mega-berg has now virtually gone,broken into countless small parts that the US National Ice Center says is no longer worth tracking.It stayed relatively the same size for the first two years of its life as it stayed in the cold waters of the Weddell Sea near the Antarctic Peninsula.Then it started its“epic”journey across the Drake Passage,and everything changed.As of January 2022,it had lost more than half of its area.Now,it’s a little bigger than Rhode Island.

In the time it’s been around South Georgia,researchers found,the iceberg released roughly 152 billion tons of fresh water and nutrients into the ocean over the course of about three months.That amount of water could fill about 61 million Olympic-sized swimminɡ pools.This siɡnificant loss could result in“potentially impacting the island’s rich ecosystem”,the study says.

South Georgia and the South Sandwich Islands are a“heaven for wildlife”,servinɡ as home to rouɡhly 5 million seals and 30 different bird species,a third of which are considered threatened or near-threatened.Researchers added,however,that the melting could potentially change the ocean in a way that also impacts currents,which could,“in the worst case”,divert krill,an important source of food for whales,away from the island.

Studies on this fantasy rafting are still ongoing.

6) satellite [?s?t?la?t] n.衛(wèi)星

7) bulk [b?lk] n.體積

8) disrupt [d?s?r?pt] v.破壞；使分裂

詞組加油站

break off 使脫落；把……折斷

thousands of 成千上萬

漂浮在海洋中的一大塊冰被稱為冰山。許多冰山如房屋或大型建筑物一樣大。冰山來自冰川，是冰川斷裂后落入大海的碎片，這些碎片可以漂流數(shù)千英里。當(dāng)?shù)竭_(dá)足夠溫暖的水域時(shí)，它們就會(huì)融化。每年在北極和南極，都會(huì)形成數(shù)以千計(jì)的冰山。

史上最大的冰山有數(shù)英里寬、數(shù)百英尺高。盡管冰山非常重，但它們漂浮的原因與冰塊漂浮在一杯水中的原因一樣：冰比水的密度?。ɑ蜉p）。然而，冰山大部分的體積都隱藏在水下，很容易損壞或摧毀過往的船只。

任何撞上冰山的船都可能受到損壞。歷史上最著名的冰山撞擊事件是1912 年4 月14 日，一座冰山撞沉了在北大西洋航行的泰坦尼克號(hào)。船身一側(cè)撞到了冰山，船體被撞出了大洞。不到三個(gè)小時(shí)，船就沉到了海底。

泰坦尼克號(hào)失事后，幾個(gè)國家共同建立了國際冰情巡邏隊(duì)，警告船只注意大西洋航線上漂浮的冰山。

我們或許可以從“A68a”冰山的漂移中一窺冰山的變化。

“A68a”是有記錄以來最大的冰山之一。在2017 年脫離南極洲時(shí)，它的面積是盧森堡的兩倍。世界各地的人們都在網(wǎng)上分享了它的實(shí)時(shí)衛(wèi)星圖像，尤其是當(dāng)這塊冰接近南喬治亞島時(shí)。如果它擱淺，這座體積巨大的冰山可能會(huì)擾亂島上許多企鵝的行為——誰不擔(dān)心處于瀕危之際的企鵝呢？

但衛(wèi)星顯示，這座巨型冰山現(xiàn)在實(shí)際上已經(jīng)消失了，變成無數(shù)小碎片，美國國家冰川中心稱這些碎片不再值得追蹤。因?yàn)橥Ａ粼谀蠘O半島附近威德爾海的寒冷水域中，前兩年冰山還保持了原有的大小。自從它開始“穿越”德雷克海峽的“史詩”之旅，一切都發(fā)生了變化。截至2022 年1 月，它已經(jīng)失去了一半以上的面積。現(xiàn)在，它只比羅德島大一點(diǎn)。

研究人員發(fā)現(xiàn)，在繞著南喬治亞島的那段時(shí)間里，這座冰山在大約三個(gè)月的時(shí)間里向海洋釋放了大約1520 億噸淡水和營養(yǎng)物質(zhì)。這樣的水量可以填滿大約6100 萬個(gè)奧林匹克規(guī)模的游泳池。研究稱，冰山的這一重大損失可能“影響島上豐富的生態(tài)系統(tǒng)”。

南喬治亞和南桑威奇群島是“野生動(dòng)物的天堂”，是大約500 萬只海豹和30種不同鳥類的家園，其中三分之一被認(rèn)為受威脅或近危。然而，研究人員補(bǔ)充說，融化可能會(huì)以一種影響洋流的方式來改變海洋。在“最壞的情況下”，這可能會(huì)使磷蝦（鯨魚的重要食物來源）遠(yuǎn)離島嶼。

人們對(duì)這場冰山的奇幻漂流仍在持續(xù)研究中。