BBC《行星地球》第二集解说词.docx

2. Mountains
Human beings venture into the highest parts of our at their peril. Some might think that by climbing a great mountain they have somehow conquered it, but we can only be visitors here. This is a frozen alien world. This is the other extreme - one of the lowest hottest places on Earth. It's over a hundred metres below the level of the sea. But here a mountain is in gestation. Pools of sulphuric acid are indications that deep underground there are titanic stirrings. This is the Danakil Depression in Ethiopia, lying within a colossal rent of the earth's surface where giant land masses are pulling away from one another. Lava rises to the surface through this crack in the crust creating a chain of young volcanoes. This one, Erta Ale, is today the longest continually erupting volcano on the , a lake of lava that has been molten for over a hundred years. These same volcanic forces also created Ethiopia's highlands. 70 million years ago this land was just as flat and as deep as the Danakil Depression. Molten lava rising from the earth's core forced up a huge dome of rock 500 miles wide, the roof of Africa. Over millennia, rain and ice carved the rock into a landscape of spires and canyons. These summits, nearly 3 miles up, are home to some very remarkable mountaineers Gelada baboons. They are unique to the highlands of Ethiopia. The cliffs where they sleep are for expert