英语听力：探索发现 2014-07-06 BBC 地平线：陨石的真相-24（在线收听） |
The meteorite was 15 kilometres across, enough to cause utter devastation across the whole planet. It exploded with a force of 100 million million tones of TNT. The blast sent a giant plume of vaporized rock out into space. A crater was punched 30 kilometres into the Earth’s crust. It was above this rim of weakened rock that these cenotes formed millions of years later. The blast would have been ferocious. But it was what happened next that made the impact a global catastrophe. The blast plume that shot into space fell back to Earth. Billions of molten particles superheated the air to a temperature of hundreds of degrees. Fires swept the planet, choking the atmosphere with soot and dust. The dinosaurs, and most other creatures, were doomed.
That discovery, back in the 1980s, about what happened at Chicxulub, changed everything. Up until then, we thought that the Earth had changed only through grindingly slow processes, but now we knew that there was also sudden, violent catastrophes that made the Earth the way it was. Of course, what that meant was that something like this could happen again, at any moment. |
| 原文地址：http://www.tingroom.com/lesson/yytltsfx/2014/273558.html |