十万个为什么·科学启蒙30篇（1）

19 / 30

为什么山脉会随着时间越来越高？

Mountains grow taller when tectonic plates push against each other underground.
This slow collision crumples Earth's crust and lifts land upward like folded paper.
Some mountains, like the Himalayas, rise about one centimeter every year on average.
Erosion from wind and rain tries to wear them down at the same time.
But in active zones, uplift often outpaces erosion over long periods.
Scientists measure mountain growth using GPS satellites and precise laser surveys.
Volcanic activity can also add height quickly when magma rises and hardens.
Rock layers deep underground bend and break to accommodate the rising force.
Even though growth is tiny yearly, it adds up over millions of years.
That’s why today’s tallest peaks were once flat seabeds long ago.