科学家在冰川中寻找历史线索
英语课
A group of scientists from the Ohio State University are trekking 1 to the top of the Quelccaya Ice in the Peruvian Andes to try to measure the effects of climate change on the world's glaciers 3.
The average distance above sea level on the glacier 2 is around 54-hundred-70 meters.
The Quelccaya ice cap is the largest tropical ice cap on Earth.
Paleoclimatologist Doctor Lonnie Thompson says they believe inside is an annual record of the earth's climatic changes covering the last 18-hundred years.
科学家在冰川中寻找历史线索
"The day will come when there will no longer be a Quelccaya Ice Cap and the history that is preserved here will no longer be available, so in many ways we are also salvaging 4 a history of our past that will be lost as the earth continues to warm,."
Thompson and his team spent a week in June on the Quelccaya glacier, drilling ice and snow samples to measure the isotopes 5 in the annual dust layers.
The isotopes provide a history of precipitation, allowing the glaciologists to analyse the ice layer-by-layer through the centuries to try to understand how ancient weather shifted.
Flecks 6 of dust, falling seasonally 7, enable them to count down the years, much like the rings in a tree.
The chemistry of the snow can also help scientists trace the effects of human pollution, such as chemicals and metals in the atmosphere.
Researcher Doctor Emilie Beaudon is looking into this aspect of the research in the Andes.
"We don't know how well they (contaminants) are deposited in the ice cap yet, but our objective is to try to measure that, and since the ice cap is meant to melt and those contaminants are meant to be released on the environment we would like to quantify this contamination and see if it could have any impact on on human health."
Photographs taken over a 33-year period suggest the speed of their research is becoming more urgent, as parts of the glacier have been disappearing by as much as 50-percent over the past 3-decades.
A World Bank report drafted in 2009 suggests global climate change threatens the complete disappearance 8 of the Andes' tropical glaciers within the next 20 years, putting precious water, energy and food sources at risk.
For CRI, I'm Wang Mengzhen
v.艰苦跋涉，徒步旅行( trek的现在分词 )；（尤指在山中）远足，徒步旅行，游山玩水
- She can't come pony trekking after all because she's in a delicate condition. 她结果还是不能坐小马车旅行，因为她已怀孕。 来自《简明英汉词典》
- We spent the summer trekking in the foothills of the Himalayas. 我们整个夏天都在喜马拉雅山的山麓艰难跋涉。 来自互联网
n.冰川，冰河
- The glacier calved a large iceberg.冰河崩解而形成一个大冰山。
- The upper surface of glacier is riven by crevasses.冰川的上表面已裂成冰隙。
冰河，冰川( glacier的名词复数 )
- Glaciers gouged out valleys from the hills. 冰川把丘陵地带冲出一条条山谷。
- It has ice and snow glaciers, rainforests and beautiful mountains. 既有冰川，又有雨林和秀丽的山峰。 来自英语晨读30分（高一）
（从火灾、海难等中）抢救（某物）( salvage的现在分词 )； 回收利用（某物）
- A shipping company has made a claim for the cost of salvaging a sunken ship. 某轮船公司要求赔赏打捞沉船的费用。（make a claim 要求）
- It is not uncommon to hear that a shipping company has made a claim for the cost of salvaging a sunken ship. 航运公司为打捞沉船的费用而提出要求，这并非奇闻。
n.同位素；同位素( isotope的名词复数 )
- the many isotopes of carbon 碳的诸多同位素
- Tritium is one of the mildest radioactive isotopes. 氚是最和缓的放射性同位素之一。 来自《简明英汉词典》
n.斑点，小点( fleck的名词复数 )；癍
- His hair was dark, with flecks of grey. 他的黑发间有缕缕银丝。
- I got a few flecks of paint on the window when I was painting the frames. 我在漆窗框时，在窗户上洒了几点油漆。 来自《简明英汉词典》
- The price of vegetables fluctuates seasonally. 蔬菜的价格随季节变动。 来自《简明英汉词典》
- They moved seasonally among various vegetation types to feed on plants that were flourishing. 它们还随着季节的变化而在各种类型植物之间迁移，以便吃那些茂盛的植物。 来自辞典例句
n.消失，消散，失踪
- He was hard put to it to explain her disappearance.他难以说明她为什么不见了。
- Her disappearance gave rise to the wildest rumours.她失踪一事引起了各种流言蜚语。
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