VOA标准英语2013--Researchers Record Iceberg Breaking Loud as an Earthquake

 

Researchers Record Iceberg¹ Breaking Loud as an Earthquake

The sound can be mistaken as a stringed instrument like a double bass², or maybe some kind of truck on the highway. But it actually is an iceberg, in the Antarctic Weddell Sea, grinding slowly against the seafloor.

“The iceberg is essentially³ scraping along and more or less resonating, kind of like a tuning⁴ fork,” explained Robert Dziak of Oregon State University.

Dziak led a team of scientists monitoring a collection of underwater microphones around the Antarctic Peninsula, the northernmost part of the southern continent. They detected the sounds of an iceberg being born, as it cracked off the ice of the mainland. “It’s big. It’s about 25 by 50 kilometers in dimension, length and width. So it’s essentially a little floating island out there that’s moving around in the Southern Ocean.”

Over the course of its life, from its calving to its journey toward warmer seas to its eventual⁵ melting, the iceberg was never out of range of the team’s microphones.

"We saw from the beginning to its actual eventual death, for lack of a better word,” he stated.

Dziak believes this is the first time anyone has listened to a single iceberg for its entire life. And what his team heard when the iceberg floated into the warmer Scotia Sea was astonishing. “As it begins to enter warmer water, it begins to melt. And it can melt catastrophically,” he said. “.”

That’s as loud as a small earthquake, Dziak said, loud enough to resonate all the way up to the equator.

The oceanographers wondered if this much noise could pose a problem for marine⁶ animals, which use sound to navigate⁷, communicate and find food. Bioacoustician Chris Clark of Cornell University studies the effect of underwater sound on ocean life.

“Whales, and fishes, as a matter of fact, and now even all the invertebrates⁹, like the lobsters¹⁰ and the shrimp¹¹ and crabs¹² and things like that, are all paying attention to sound,” said Clark. “There’s been this increasing awareness¹³ and concern about noise in the ocean - is it good, is it bad, are we indifferent, what’s going on?”

Human-created sound in the ocean is on the rise, from increased shipping¹⁴ traffic, seismic¹⁵ testing and military sonar, and researchers are demonstrating more and more that ocean life is being affected¹⁶. The noise, Clark said, can make it impossible for animals to hear the things they need to hear in order to live.

“We refer to it as acoustic⁸ bleaching,” explained Clark. “It’s as though suddenly there’s a big fog bank that just comes into where you’re living and suddenly you can’t see very far, only in this case the fog bank is noise.”

But Clark said that temporary, natural sounds - like an iceberg cracking apart, though they may be as loud as an earthquake - are probably not nearly as harmful to marine life as manmade sounds. “It’s one thing to have evolved over 5 or 6 million years in a world that’s dynamic, with storms, with ice. The human-generated noise in the ocean is so chronically¹⁷ persistent¹⁸, it’s now a real concern, and it dwarfs¹⁹ collective noise generated by icebergs,” he said.

Still, researchers say this is a time of warming oceans. Climate change may lead to more polar ice breaking apart, and shattering loud like earthquakes in the Southern seas.

1 iceberg   

n.冰山，流冰，冷冰冰的人

参考例句：

• The ship hit an iceberg and went under.船撞上一座冰山而沉没了。
• The glacier calved a large iceberg.冰河崩解而形成一个大冰山。

2 bass   

n.男低音(歌手)；低音乐器；低音大提琴

参考例句：

• He answered my question in a surprisingly deep bass.他用一种低得出奇的声音回答我的问题。
• The bass was to give a concert in the park.那位男低音歌唱家将在公园中举行音乐会。

3 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

4 tuning   

n.调谐，调整，调音v.调音( tune的现在分词 )；调整；（给收音机、电视等）调谐；使协调

参考例句：

• They are tuning up a plane on the flight line. 他们正在机场的飞机跑道上调试一架飞机。 来自《简明英汉词典》
• The orchestra are tuning up. 管弦乐队在定弦。 来自《现代汉英综合大词典》

5 eventual   

adj.最后的，结局的，最终的

参考例句：

• Several schools face eventual closure.几所学校面临最终关闭。
• Both parties expressed optimism about an eventual solution.双方对问题的最终解决都表示乐观。

6 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

7 navigate   

v.航行，飞行；导航，领航

参考例句：

• He was the first man to navigate the Atlantic by air.他是第一个飞越大西洋的人。
• Such boats can navigate on the Nile.这种船可以在尼罗河上航行。

8 acoustic   

adj.听觉的，声音的；(乐器)原声的

参考例句：

• The hall has a fine acoustic.这个大厅的传音效果很好。
• Animals use a whole rang of acoustic, visual,and chemical signals in their systems of communication.动物利用各种各样的听觉、视觉和化学信号来进行交流。

9 invertebrates   

n.无脊椎动物( invertebrate的名词复数 )

参考例句：

• Insects and worms are all invertebrates. 昆虫和蠕虫都是无脊椎动物。 来自辞典例句
• In the earthworm and many other invertebrates, these excretory structures are called nephridia. 在蚯蚓和许多其它无脊椎动物中，这些排泄结构称为肾管。 来自辞典例句

10 lobsters   

龙虾( lobster的名词复数 )； 龙虾肉

参考例句：

• I have no idea about how to prepare those cuttlefish and lobsters. 我对如何烹调那些乌贼和龙虾毫无概念。
• She sold me a couple of live lobsters. 她卖了几只活龙虾给我。

11 shrimp   

n.虾，小虾；矮小的人

参考例句：

• When the shrimp farm is built it will block the stream.一旦养虾场建起来，将会截断这条河流。
• When it comes to seafood,I like shrimp the best.说到海鲜，我最喜欢虾。

12 crabs   

n.蟹( crab的名词复数 )；阴虱寄生病；蟹肉v.捕蟹( crab的第三人称单数 )

参考例句：

• As we walked along the seashore we saw lots of tiny crabs. 我们在海岸上散步时看到很多小蟹。 来自《简明英汉词典》
• The fish and crabs scavenge for decaying tissue. 鱼和蟹搜寻腐烂的组织为食。 来自《简明英汉词典》

13 awareness   

n.意识，觉悟，懂事，明智

参考例句：

• There is a general awareness that smoking is harmful.人们普遍认识到吸烟有害健康。
• Environmental awareness has increased over the years.这些年来人们的环境意识增强了。

14 shipping   

n.船运（发货，运输，乘船）

参考例句：

• We struck a bargain with an American shipping firm.我们和一家美国船运公司谈成了一笔生意。
• There's a shipping charge of ￡5 added to the price.价格之外另加五英镑运输费。

15 seismic   

a.地震的，地震强度的

参考例句：

• Earthquakes produce two types of seismic waves.地震产生两种地震波。
• The latest seismic activity was also felt in northern Kenya.肯尼亚北部也感觉到了最近的地震活动。

16 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

17 chronically   

ad.长期地

参考例句：

• Similarly, any pigment nevus that is chronically irritated should be excised. 同样，凡是经常受慢性刺激的各种色素痣切勿予以切除。
• People chronically exposed to chlorine develop some degree of tolerance. 人长期接触氯气可以产生某种程度的耐受性。

18 persistent   

adj.坚持不懈的，执意的；持续的

参考例句：

• Albert had a persistent headache that lasted for three days.艾伯特连续头痛了三天。
• She felt embarrassed by his persistent attentions.他不时地向她大献殷勤，使她很难为情。

19 dwarfs   

n.侏儒，矮子（dwarf的复数形式）vt.（使）显得矮小（dwarf的第三人称单数形式）

参考例句：

• Shakespeare dwarfs other dramatists. 莎士比亚使其他剧作家相形见绌。 来自《简明英汉词典》
• The new building dwarfs all the other buildings in the town. 新大楼使城里所有其他建筑物都显得矮小了。 来自辞典例句