Login

What Is Topography and How Is Topography Reshaped?

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Effect of Erosion and Deposition on Landforms

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:34 Mechanical Weathering
  • 1:32 Chemical Weathering
  • 2:05 Erosion
  • 2:50 Deposition of Sediment
  • 3:34 Natural Disasters
  • 4:06 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Danielle Lavallo

Danielle has taught computer technology and gifted education classes. She has a master's degree in teaching and learning.

The topography, or surface of the Earth, is constantly changing shape due to many powerful forces. In this lesson, we will learn about some of the amazing changes that occur on Earth due to the processes of weathering, erosion, and deposition.

What Is Topography?

Have you ever had a brand-new eraser? If so, you probably noticed that over time and with regular use, its shape changed. What forces caused this? Just like an eraser, the surface of the Earth can also change shape.

Topography is the shape of Earth's surface and its physical features, such as mountains, valleys, canyons, and other landforms. In this lesson, we will explore Earth's topography and how it is continuously being reshaped due to many powerful processes that break it down and build it up.

Mechanical Weathering

Nature is powerful and it can break down even the hardest rock or mineral on Earth. Weathering is the wearing away of rock or soil by wind, water, or any other natural cause. There are two types of weathering: mechanical and chemical.

Mechanical weathering occurs when a force, such as water, wind, or ice, moves soil or breaks rocks into smaller pieces. When water moves across rocks, it causes them to break down. When it flows into cracks in rocks and freezes, the ice causes them to split and break apart.

Extreme temperature changes cause rocks to expand and contract, which makes them weaken and break apart. Sand is created when crashing waves break rock apart into tiny pieces. Plant roots, animals pushing up or digging through the Earth, and even gravity, which can trigger avalanches, can cause rock and soil to move.

Chemical Weathering

In chemical weathering, the chemical makeup of the rock is permanently changed due to reactions between rocks and chemicals, such as oxygen or carbon dioxide. Humans and animals release carbon dioxide when they breathe, which, when mixed with water, creates a type of acid that breaks down rock. Acid rain is caused when chemicals from air pollution mix with rainwater and is a type of chemical weathering that can dissolve rock. The Carlsbad Caverns in New Mexico were formed as a result of chemical weathering.

Erosion

Erosion occurs when pieces of Earth that have been weathered and worn away are moved to another place. Wind can carry soil and rock far distances. Along the way it can blast the sides of rocks and mountains, changing their shape. Glaciers, which are huge moving masses of ice and snow, can scrape against rock and soil and carry it away.

Water, in the form of rain, rivers, and waves, causes erosion of rock and soil. Erosion changes the shape of coastlines, mountains, and many other landforms. All rocks on the Earth are vulnerable to weathering and erosion. You need only look at a picture of the Grand Canyon in Arizona to understand how powerful these processes are!

Deposition of Sediment

Getting back to the eraser example, you probably noticed the pesky little bits of rubber that came off onto your paper when you rubbed the eraser against it. This is like sediment, or pieces of the Earth that have been broken off by erosion. Chances are that you brushed them off onto the floor or into the wastebasket.

This is similar to the process of deposition, which happens when Earth material that has been eroded is placed, or deposited, in another area. The deposition of sediment can create many new landforms. It is responsible for the formation of certain types of islands, sand dunes on beaches and in deserts, and river deltas.

To unlock this lesson you must be a Study.com Member.
Create your account

Register for a free trial

Are you a student or a teacher?
I am a teacher

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it free for 5 days!
Create An Account
Support