Book 5, Question 61 · Video
Up, Up, Up! Why Do Mountains Rise?
Some mountains rise when two of Earth's plates push against each other and the land crumples and lifts up. It takes millions of years. Some mountains are also built by volcanoes.
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What Crafty Clover says in this video
Intro
Hi! I'm Crafty Clover! Let's discover something amazing. Why do mountains rise?
The Big Idea
Mountains can be huge and tall. But how does solid ground go up? Earth's plates crunch into each other. The rock has nowhere to go but up, and it piles up and folds. Plates crunch, and rock piles up! Let's see how.
Step 1
Step one: two plates push together. Two plates slowly move toward each other. They only travel a few centimeters a year, but they push with incredible force. The rock in between has nowhere to go.
Step 2
Step two: the rock crumples and folds. The layers of rock get squeezed and buckle upward. It's like pushing a rug from both ends, so it wrinkles up. Some rock also cracks and slides on top of other rock.
Step 3
Step three: a mountain range grows. After millions of years of pushing, the rock piles up into towering mountains. Wind, ice, and rain wear them down too, so tall mountains are always a race between rising and wearing away.
A Closer Look
Let's peek inside a young mountain range. The layers are folded up and tilted. These layers may have started as flat sediment, even seafloor. The peak is the highest point, and it's still being pushed up.
Quick Facts
Quick facts! Mount Everest is the tallest mountain above sea level, and the Himalayas are still rising about a few millimeters each year. Seashell fossils have been found high up on mountains, because that rock started out as seafloor. Big mountain ranges take tens of millions of years to build. Grown-up note: leave fossils and rocks in place in parks and on mountains.
Think Like a Scientist
Now, think like a scientist! Try this with a grown-up. Lay a towel flat on a table, and push both ends toward each other. Watch the middle fold up into a ridge. How is that like plates making mountains?
Outro
So mountains rise when plates crunch together and the rock piles up. Amazing, right? Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!