VOA慢速英语2020 新研究表明南极洲曾经是雨林（在线收听）

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 sediment 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 dinosaurs 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 Glacier.

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 geologist with the Alfred Wegener Institute's Helmholtz Center for Polar and Marine 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 Celsius. 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 dense 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 remains were found, Klages said there were likely dinosaurs, flying reptiles 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 seasonal 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。