单词：beringia
单词：beringia 相关文章
By searching for evidence that still survives today, we reconstruct the landscape and the wildlife of prehistoric North America. During the last Ice Age, massive glaciers covered half of North America. But to the far northwest, there was a land that
探索与发现2012年
The Yukon and its neighbor, modern-day Alaska, were once part of the land that was Beringia. Stunning though this region is today is just a shadow of the world that was encountered by the First Americans. Underground, the soil is frozen solid, as it
探索与发现2012年
This is Alaska today, a wetland of forests, boggy tundra, lakes and rivers rivers that still churn out fresh clues to the Ice Age past. This is a brick-sized tooth, and it belong to a woolly mammoth. Its narrow ridges of enamel tell us more about how
探索与发现2012年
The fact that both horses and mammoths were here suggests these forests werent. It seems that, 14,000 years ago, Beringia was a huge expanse of open grassland. This unique habitat of cold, dry grasslands is known as mammoths steppe. But thats not how
探索与发现2012年
At its maximum, the ice covered nearly six million square miles. And in places, it was up to two miles thick. The ice blanket was punctuated only by occasional islands of rock, the peaks of the very highest mountains. Though Beringia itself remained
探索与发现2012年
Arctic ground squirrels hibernate like other small mammals, but with a unique twist. They can lower their body temperature right down to almost minus 3 degrees centigrade. But thanks to a biochemical super-cooling process, they dont actually freeze.
探索与发现2012年