Why Do Normal Faults Drop Blocks Down?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why do normal faults drop blocks down?

The Big Idea

Where Earth's crust is being pulled apart, a block of rock can slip down along a steep crack. That crack is called a normal fault. Normal does not mean usual. It is just the name!

Pulled Apart

Step one: pulled apart. In some places, forces pull the crust in opposite directions. The crust gets stretched, like pulling taffy.

Blocks Drop

Step two: blocks drop. The rock breaks along a steep, slanted crack called a normal fault. The block above the fault, called the hanging wall, slides down.

Steps and Valleys

Step three: steps and valleys. Over a long time, many drops make steep cliffs and long valleys. The land looks like giant stairs. Each quake can raise one side and lower the other by a few centimeters or more.

A Closer Look

Let's take a closer look! The crust is pulled apart. A slanted crack forms. The hanging wall drops down. And the other side stands up as a cliff.

Quick Facts

Quick facts! Normal doesn't mean usual, it is just the name. Parts of the western United States have many normal faults. Valleys between them are called basins, and mountain blocks stand beside them. Normal faults can cause strong earthquakes too.

Think Like a Scientist

Now, think like a scientist! Ask a grown-up to cut a block of soft clay at an angle with a plastic knife. Slide the top piece down along the cut. You have made a normal fault! See the step it makes?

Outro

Normal faults happen where the crust is pulled apart and a block drops down. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!