04 山能有多高?How Tall Can Mountains Be

未能成功加载,请稍后再试
0/0

Olympus Mons, the tallest mountain in our Solar System, towers 21,000 meters above the surface of Marsnearly two and a half times the height of Mount Everest.

On Earth, you would need a spacesuit to survive at that altitudebut could there even be a mountain that tall here on our home planet?

Based on the strength of Earth's gravity and the density and strength of rock, in principle, you could make a single conical mountain that stretched between New York and Chicago and soared over 45 km!

That's twice the size of Olympus Mons and definitely dwarfs Everest.

However, there are a couple of reasons why we can't actually have that humongous of a mountain here on Earth:

For one, Earth's crust is made up of continental plates that essentially float in the semi-solid rock of the mantle below.

If you add more weight above the surface, they sink lower into the earth's hot interior, and when they sink far enough, they soften and basically melt.

For our conical mountain, that gives a new height limit of just 15km.

As well, the powerful collision of two tectonic plates, which creates mountains in the first place, also fractures and cracks the rock, weakening its structure and exposing it to erosion.

Over millions of years, freeze-thaw cycles pry at these cracks, while winds claw at the slopes and streams and glaciers carve deep valleys into the mountainside, all weakening the mountain's support, this can end badly.

下载全新《每日英语听力》客户端,查看完整内容