Constructive Processes


Read the background information carefully. There is a lot of information to absorb, so take notes on new and interesting things you read. Try to make connections between the different processes and your own experiences. Watch video. If possible, implement the activity shown in the video. If this is not possible, watch the video closely to see the effects of constructive processes. gjhghjfyf

Background Information
Constructive processes, or forces, are the events that occur to change and create new matter in the earth's surface. Constructive forces include earthquakes, deposition, volcanoes, and faults. When new matter is created on the earth's surface, humans are effected. Earthquakes and erupting volcanoes are not only frightful, they can destroy valuable resources, houses, and even result in death, though such events are not typically fatal.

When the tectonic plates that make-up the earth's surface move against one another, an earthquake occurs. Humans can often feel earthquakes, and are advised to position themselves in doorways or under desks if they feel a room shaking. When an earthquake occurs, the plates sometimes push up on one another, depositing new matter on the surface of the earth. In this instance, the earthquake is a constructive force. Earthquakes are typically caused by faults. To learn more about faults, keep reading, and be sure to watch the video on this page! In the next lesson, you will see how earthquakes may also be a destructive force.

When matter is deposited, or put down, in a new place, we say deposition has occurred. This typically takes place after wind or water has eroded sand and soil, making it loose and susceptible to movement. Deposition often occurs in rivers, forming a river delta, or on beaches, forming sand dunes. Though this does not have the drastic effect on human life that volcanoes and earthquakes can have, the creation of deltas and sand dunes can still impact life. Often, the soil in deltas is rich with nutrients and thus can provide great resources for crops. Sand dunes, on the other hand, provide a unique environment to plant and animal species. Though this may have little direct impact on humans, it is necessary for us to preserve the dunes in order to protect the fragile life that lives there.

Did you know the islands of Hawaii were formed on the tops of volcanoes? When volcanoes erupt, the magma that is released dries and hardens, making new material on the earth's surface. Many mountains are dormant volcanoes, meaning they are no longer active.

Cracks in the surface of the earth, where rocks break and slide past each other, are called faults. There are three types of faults you need to know about: normal, reverse, and strike-slip. Here's how I remember the different kinds of faults...
For normal and reverse faults, imagine a parking lot. Two cars have backed into adjoining spaces, parked trunk to trunk. In a normal situation, much like a normal fault, each driver starts his car, and drives away from the other car. Similarly, in a normal fault, the two plates move away from each other.
On the other hand, in a reverse fault, the same two drivers are not paying attention. Pretend they're sending a text message while they start their cars. Instead of putting the car into drive, these two drivers put their car into reverse. When they hit the gas, their cars go backwards, right into each other. In the same way, in a reverse fault the two plates hit each other, and matter is built up from the crash.
Strike-slip faults are nearly self explanatory. Two faults strike against each other, and then slip past each other. If you clap your hands, and then rub one up and the other down, you can demonstrate a strike-slip fault.

Now that you know the different types of constructive processes, let's see a demonstration:


Bubble gum
Chocolate bar--any type


Did you follow all directions in this lesson? Do you understand the causes and effect of constructive forces? What are some types of constructive forces? What happens during a compression force?