Don:Yael, I'm going to take some vacation time so I can visit Chicago before it sinks and disappears.
唐:雅艾尔,我要休假,这样我就能在芝加哥下沉，消失之前去这个地方看看了。
I mean, I'd like to see the Sears Tower and eat some deep-dish pizza before it goes.
我想看看西尔斯大厦，还要吃一些加厚比萨饼。
Yael:Relax, Don. Although Chicago is sinking, we're only talking one millimeter a year—
雅艾尔:冷静点,唐。虽然芝加哥正在下沉,但我们所讲的是一年一毫米的速度。
Don:But that's four inches in a century!
唐:但一个世纪就是4英寸！
Yael:But only until the land in North America brings itself back into equilibrium.
雅艾尔:但只要北美的土地恢复平衡后就会好了。
Don:What do you mean?
唐:此话怎讲?
Yael:Well, when glaciers covered Canada and the northern Great Lakes tens of thousands of years ago, their weight pushed down on the Earth's surface and caused it to sag.
雅艾尔:嗯,数万年前冰川覆盖加拿大和北方的大湖时,其体积造成地球表面下沉。
And this pressure forced the Earth's mantle, the layer of hot, plastic rock that's located beneath the Earth's crust, to give way and ooze out and sideways.
而这种压力迫使地球地壳中的热层地幔层的塑性岩石垮掉并移到一边。
Don:Oh! It's like the Earth is a giant waterbed.
唐:哦!这就像地球是一个巨大的水床。
When you lie down on it, the surface of the mattress under you sinks, forcing the water into other parts of the mattress.
当你躺下,床垫的表面随你下沉而迫使水到床垫的其他部分。
Yael:You have a water bed?
雅艾尔:你有张水床?
Don:But of course.
唐:当然。
Yael:Anyway. In the twelve thousand years since the glaciers receded, the Earth's crust has been slowly returning to its original shape.
雅艾尔:不管怎样。在一万二千年,自从冰川消退后,地壳开始逐渐恢复到原来的形状。
So the land in Canada and the northern Great Lakes is slowly rising, while the rest of North America is slowly sinking, like a seesaw, enabling the mantle to flow back north.
所以加拿大和北部五大湖的土地慢慢上升,而北美的其他地方在慢慢下沉,这就像个跷跷板,使地幔向北移动。
And as the Lake Michigan floor north of Green Bay rises, all that water sloshes south towards Chicago.
而随着密西根湖楼格林贝北部的上升,水也朝向芝加哥南部。
Don:Kind of like tilting a bathtub.
唐:有点像倾斜的浴缸。
Yael:Yep.
雅艾尔:是的。
Don:Hmm! So even if I don't have to rush out for pizza, it does sound like an issue from a Great Lakes management perspective.
唐:嗯!所以即使我不用急着去那里吃披萨,这听起来确实是五大湖管理面临的管理前景问题。
Yael:It sure is.
雅艾尔:的确是这样。
