冰山奇幻漂流

罗亚琪

冰山是一塊大若山川的冰，脱离了冰川或冰架，在海洋里漂流。而我们常用“冰山一角”来形容问题很严重，这是因为冰山约有90%的体积是在海面以下，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.

词组加油站

break off 使脱落;把……折断

thousands of 成千上万

漂浮在海洋中的一大块冰被称为冰山。许多冰山如房屋或大型建筑物一样大。冰山来自冰川，是冰川断裂后落入大海的碎片，这些碎片可以漂流数千英里。当到达足够温暖的水域时，它们就会融化。每年在北极和南极，都会形成数以千计的冰山。

史上最大的冰山有数英里宽、数百英尺高。尽管冰山非常重，但它们漂浮的原因与冰块漂浮在一杯水中的原因一样：冰比水的密度小（或轻）。然而，冰山大部分的体积都隐藏在水下，很容易损坏或摧毁过往的船只。

任何撞上冰山的船都可能受到损坏。历史上最著名的冰山撞击事件是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号。船身一侧撞到了冰山，船体被撞出了大洞。不到三个小时，船就沉到了海底。

泰坦尼克号失事后，几个国家共同建立了国际冰情巡逻队，警告船只注意大西洋航线上漂浮的冰山。

我们或许可以从“A68a”冰山的漂移中一窥冰山的变化。

“A68a”是有记录以来最大的冰山之一。在2017年脱离南极洲时，它的面积是卢森堡的两倍。世界各地的人们都在网上分享了它的实时卫星图像，尤其是当这块冰接近南乔治亚岛时。如果它搁浅，这座体积巨大的冰山可能会扰乱岛上许多企鹅的行为——谁不担心处于濒危之际的企鹅呢？

但卫星显示，这座巨型冰山现在实际上已经消失了，变成无数小碎片，美国国家冰川中心称这些碎片不再值得追踪。因为停留在南极半岛附近威德尔海的寒冷水域中，前两年冰山还保持了原有的大小。自从它开始“穿越”德雷克海峡的“史诗”之旅，一切都发生了变化。截至2022年1月，它已经失去了一半以上的面积。现在，它只比罗德岛大一点。

研究人员发现，在绕着南乔治亚岛的那段时间里，这座冰山在大约三个月的时间里向海洋释放了大约1520亿吨淡水和营养物质。这样的水量可以填满大约6100萬个奥林匹克规模的游泳池。研究称，冰山的这一重大损失可能“影响岛上丰富的生态系统”。

南乔治亚和南桑威奇群岛是“野生动物的天堂”，是大约500万只海豹和30种不同鸟类的家园，其中三分之一被认为受威胁或近危。然而，研究人员补充说，融化可能会以一种影响洋流的方式来改变海洋。在“最坏的情况下”，这可能会使磷虾（鲸鱼的重要食物来源）远离岛屿。

人们对这场冰山的奇幻漂流仍在持续研究中。