万物简史 第319期:美丽而危险(2)（在线收听） |
These are volcanoes so explosive that they burst open in a single mighty rupture, leaving behind a vast subsided pit, the caldera (from a Latin word for cauldron). 这种火山的威力如此之大，它们一下子破土而出，留下一个沉降式大坑，即破火山口（源自拉丁语，意思是大锅）。 Yellowstone obviously was of this second type, but Christiansen couldn't find the caldera anywhere. 黄石火山显然属于第二种，但克里斯琴森哪里也找不到那个破火山口。
By coincidence just at this time NASA decided to test some new high-altitude cameras by taking photographs of Yellowstone, 恰好在这个时候，美国国家航空和航天局决定拍摄黄石公园的照片，测试一下某些新型的高空照相机。
copies of which some thoughtful official passed on to the park authorities on the assumption that they might make a nice blow-up for one of the visitors' centers. 一位考虑周到的官员把其中的有些照片交给了公园当局，认为它们可以挂在某个游客中心。
As soon as Christiansen saw the photos he realized why he had failed to spot the caldera: virtually the whole park—2.2 million acres—was caldera. 克里斯琴森一看到这些照片，马上意识到他没有找到破火山口的原因：实际上，整个公园——9000平方公里——就是破火山口。
The explosion had left a crater more than forty miles across—much too huge to be perceived from anywhere at ground level. 火山爆发留下了一个直径将近65公里的大坑——大得从地面上的任何角度都看不明白。
At some time in the past Yellowstone must have blown up with a violence far beyond the scale of anything known to humans. 过去某个时刻，黄石公园可能被炸得七零八落，威力之大远远超过了人类已知的任何等级。
Yellowstone, it turns out, is a supervolcano. 结果发现，黄石公园是一座超级火山。
It sits on top of an enormous hot spot, a reservoir of molten rock that rises from at least 125 miles down in the Earth. 它坐落在一个巨大的热点——一个熔岩储藏所——之上。这个储藏所下达地球至少200公里深处，上至接近地面的地方，形成了一根所谓的超级热柱。
The heat from the hot spot is what powers all of Yellowstone's vents, geysers, hot springs, and popping mud pots. 热点的热量为黄石公园里所有的喷气口、间歇泉、温泉和冒泡的泥坑提供了动力。
Beneath the surface is a magma chamber that is about forty-five miles across, 地面以下是个岩浆房，直径约为72公里，
roughly the same dimensions as the park—and about eight miles thick at its thickest point. 大致相当于公园的大小，最厚的地方达13公里左右。 |
| 原文地址：http://www.tingroom.com/lesson/syysdw/wwwjs/418665.html |