VOA慢速英语2020 新研究表明南极洲曾经是雨林

Today we know Antarctica as an extreme environment containing ice and snow. But new research provides evidence that the area was very different in the past.

今天我们都知道南极洲是冰雪覆盖的极端环境。但是新研究证实该地区在过去有很大不同。

The evidence was found inside a piece of Earth sediment¹ collected by researchers from under the seafloor off the coast of Antarctica. In the sediment, they found forest soil estimated to be about 90 million years old. This would have been in the Cretaceous Period, when dinosaurs² were the main land animals.

研究人员从南极洲沿海海底之下采集到的一块地球沉积物中发现了证据。在该沉积物中，他们发现了估计有9千年历史的森林土壤。那时可能是白垩纪时期，恐龙是当时主要的陆生动物。

The sediment was removed by scientists on the research icebreaker RV Polarstern in the Amundsen Sea near the Pine Island Glacier³.

极星号破冰船上的科学家们在松岛冰川附近的阿蒙森海钻取了这些沉积物。

Johann Klages is a geologist⁴ with the Alfred Wegener Institute's Helmholtz Center for Polar and Marine⁵ Research in Germany. He was the lead writer of a study on the findings, published in the journal Nature.

约翰·克拉格斯是德国阿尔弗雷德·韦格纳研究所赫姆霍兹极地和海洋中心的地质学家。他是这项研究的主要作者，该研究发表在《自然》杂志上。

He said the sediment was collected from a depth of about 30 meters below the ocean floor. Klages said an examination showed that the material formed on land, not in the ocean.

他说，这些沉积物是从海床以下约30米深处收集到的。克拉格斯表示，检测证实，这种物质是在陆地上形成的，而不是在海洋里。

The researchers estimate that the area – about 900 kilometers from the South Pole – had average yearly temperatures of about 12 to 13 degrees Celsius⁶. During the warmest summer months, average temperatures likely reached between 20 to 25 degrees Celsius.

研究人员估计，距离南极约900公里的这片区域过去的年平均气温是12到13摄氏度。在最温暖的夏季，平均温度能达到20到25摄氏度。

The average yearly temperature in that area is about 40 degrees below zero Celsius.

该地区（目前）的年平均气温大约是零下40度。

The examination process included the use of X-ray imaging technology. Those results showed "a dense⁷ network of roots that spread through the entire soil layer," the Helmholtz Center said in a statement. The condition of the soil was in such good condition that the researchers could see individual cell structures.

检测过程包括使用X射线成像技术。赫姆霍兹中心在一份声明中表示，研究结果表明“密集的根系网络遍布了整个土壤层。”该土壤的状况非常良好，以至于研究人员可以看清单个细胞结构。

The dark brownish-gray soil included fine dirt particles and hard clay, as well as substances linked to at least 65 different kinds of plants, the study found.

研究发现，这些深棕色的土壤包含细小的淤泥颗粒和硬质粘土，以及跟至少65种不同植物相关的物质。

"If you would go to a forest near you and drill a hole, it would probably look pretty similar," Klages told the Reuters news agency.

克拉格斯对路透社表示：“如果你去附近的森林钻一个洞，它可能看起来非常相似。”

He added that the plants included trees, ferns and flowering plants. While no animal remains⁸ were found, Klages said there were likely dinosaurs, flying reptiles⁹ and many insects in the environment.

他还说，这些植物包括树木、蕨类和开花植物。虽然没有发现动物遗骸，但该生态环境中可能有恐龙、会飞的爬行动物和许多昆虫。

The research represents new evidence of the major climate changes Earth has experienced in the past - and is currently undergoing today. The soil dates back to the planet's warmest period of the past 140 million years, with sea levels about 170 meters higher than today.

这项研究提出了新的证据，证实地球过去经历过重大气候变化，并且目前仍在进行中。这些土壤可以追溯到地球过去1.4亿年来最温暖的时期，当时的海平面比今天高出约170米。

The researchers said that the rainforest environment in Antarctica was especially surprising because each year, the area experiences a four-month polar night when there is no sunlight to fuel plant life. Klages said no ice sheets were present during the time, but seasonal¹⁰ snowfall was likely.

研究人员表示，南极地区的雨林环境尤其令人惊讶，因为该地区每年都会经历4个月的极夜，那时候没有阳光可以维持植物的生命。克拉格斯表示，这段时期该地区没有冰盖的存在，但是可能会出现季节性降雪。

1 sediment   

n.沉淀，沉渣，沉积(物)

参考例句：

• The sediment settled and the water was clear.杂质沉淀后，水变清了。
• Sediment begins to choke the channel's opening.沉积物开始淤塞河道口。

2 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

3 glacier   

n.冰川，冰河

参考例句：

• 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。

4 geologist   

n.地质学家

参考例句：

• The geologist found many uncovered fossils in the valley.在那山谷里，地质学家发现了许多裸露的化石。
• He was a geologist,rated by his cronies as the best in the business.他是一位地质学家，被他的老朋友们看做是这门行当中最好的一位。

5 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。

6 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

7 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

8 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

9 reptiles   

n.爬行动物，爬虫( reptile的名词复数 )

参考例句：

• Snakes and crocodiles are both reptiles. 蛇和鳄鱼都是爬行动物。 来自《简明英汉词典》
• Birds, reptiles and insects come from eggs. 鸟类、爬虫及昆虫是卵生的。 来自《现代汉英综合大词典》

10 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。