1. What is erosion?

Unit Question: How do physical processes change the world?

Grade focus: Change

 

Erosion is the act in which earth is worn away, often by water, wind, or ice. A similar process, weathering, breaks down or dissolves rock, weakening it or turning it into tiny fragments. No rock is hard enough to resist the forces of weathering and erosion. Together, they shaped the sharp peaks of the Himalaya Mountains in Asia and sculpted the spectacular forest of rock towers of Bryce Canyon, in the U.S. state of Utah.

Screenshot 2014-05-06 13.17.37

The process of erosion moves bits of rock or soil from one place to another. Most erosion is performed by water, wind, or ice (usually in the form of a glacier). These forces carry the rocks and soil from the places where they were weathered. If water is muddy, it is a sign that erosion is taking place. The brown color indicates that bits of rock and soil are suspended in the water and being transported from one place to another. This transported material is called sediment.

When wind or water slows down, or ice melts, sediment is deposited in a new location. As the sediment builds up, it creates fertile land. River deltas are made almost entirely of sediment. Delta sediment is eroded from the banks and bed of the river.

 

We’re going to read through these pages in class and you are going to answer the questions in your note books.

What is weathering?

What is erosion?

ACTIVITY

You are going to view and recreate the film below – ‘Erosion Lab’

In groups, you will be recreating these erosion experiments and filming them to produce your own Erosion Lab film. You also need to create annotations over your film which explain the erosion occurring in your experiments. To do this you will need to perform some research – a good starting point are the readings on the Edublog under Fluvial Erosion.

The following key words will help you to plan your research and MUST appear in your film:

  • Delta
  • Landslide
  • Wave cut platform
  • Wave cut notch
  • Undercutting
  • Deposition
  • Hydraulic action
  • Abrasion
  • Attrition
  • Vegetation cover

Choose one type of erosion from your movie. Find a natural feature that has been created by this type of erosion. Add the details of it to your movie like this:

  • Name the feature, the process which created it and show it’s geographical location
  • Use diagrams and photographs to explain how this feature was created using the process of erosion you have studied
  • Predict what the future for this feature will be and justify your prediction

Here is the final task for this unit:

Erosion – final assignment 2015

 

 

Grade 9A erosion movies