冰山奇幻漂流

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”來形容問題很嚴重，這是因為冰山約有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 ice 1）floating in the ocean is called an iceberg. Many icebergsare the size of houses or large buildings. Icebergs come from 2）glaciers. Piecesof a glacier break off into the ocean. The pieces， can 3）drift for thousands ofmiles. When they reach waters that are warm enough， they melt away. Thousandsof icebergs form each year in the Arctic and in Antarctica.

The largest icebergs ever seen were miles across and hundreds of feethigh. Although icebergs are extremely heavy， they float for the same reason thatan ice cube floats in a glass of water： ice is less dense or lighter than water. Mostof their size， however， is hidden underwater. Icebergs can easily damage or destroypassing ships.

Any ship that hits an iceberg can be damaged. The most famous iceberg inhistory sank the Titanic，a ship traveling in the northern Atlantic Ocean， on April14， 1912. The ships side 4）scraped the 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 establishthe International Ice Patrol， which warns ships about icebergs floating in Atlanticshipping 5）routes.

We may discover something from the floating of “A68a”.

“A68a” is one of the largest iceberg on record， which is equal to twice thesize of Luxembourg when it broke away from Antarctica in 2017. People around?the world shared 6）satellite pictures online， especially as the frozen blockneared South Georgia. Had it grounded， the bergs immense 7）bulk could have8）disrupted the behaviour of the islands many penguins – and who isnt worriedabout penguins in danger？

But satellites show the mega-berg has now virtually gone， broken into countlesssmall 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 inthe cold waters of the Weddell Sea near the Antarctic Peninsula. Then it startedits “epic” journey across the Drake Passage， and everything changed. As of January2022， it had lost more than half of its area. Now， its a little bigger than RhodeIsland.

In the time its been around South Georgia， researchers found， the icebergreleased roughly 152 billion tons of fresh water and nutrients into the ocean overthe course of about three months. That amount of water could fill about 61 millionOlympic-sized swimming pools. This significant loss could result in “potentiallyimpacting the islands rich ecosystem”， the study says.

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

Studies on this fantasy rafting are still ongoing.

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千英里。當到達足夠溫暖的水域時，它們就會融化。每年在北極和南極，都會形成數以千計的冰山。

史上最大的冰山有數英里寬、數百英尺高。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：冰比水的密度小（或輕）。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。船身一側撞到了冰山，船體被撞出了大洞。不到三個小時，船就沉到了海底。

泰坦尼克號失事后，幾個國家共同建立了國際冰情巡邏隊，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，它的面積是盧森堡的兩倍。世界各地的人們都在網上分享了它的實時衛(wèi)星圖像，尤其是當這塊冰接近南喬治亞島時。如果它擱淺，這座體積巨大的冰山可能會擾亂島上許多企鵝的行為——誰不擔心處于瀕危之際的企鵝呢？

但衛(wèi)星顯示，這座巨型冰山現在實際上已經消失了，變成無數小碎片，美國國家冰川中心稱這些碎片不再值得追蹤。因為停留在南極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，它已經失去了一半以上的面積?，F在，它只比羅德島大一點。

研究人員發(fā)現，在繞著南喬治亞島的那段時間里，這座冰山在大約三個月的時間里向海洋釋放了大約1520億噸淡水和營養(yǎng)物質。這樣的水量可以填滿大約6100萬個奧林匹克規(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，其中三分之一被認為受威脅或近危。然而，研究人員補充說，融化可能會以一種影響洋流的方式來改變海洋。在“最壞的情況下”，這可能會使磷蝦（鯨魚的重要食物來源）遠離島嶼。

人們對這場冰山的奇幻漂流仍在持續(xù)研究中。