Constructive forces build up and change the Earth's surface. They include deposition by water, wind or ice which forms features like deltas and sand dunes, as well as earthquakes, volcanoes, and faults. Deposition is the dropping of sediment that builds new land, deltas form at river mouths, earthquakes cause vibrations along faults, volcanoes erupt lava and ash to change mountain tops, and faults are fractures where earthquakes occur.

1. Constructive
Forces

2. GPS: S5E1. Students will identify surface features of the Earth caused by
constructive and destructive processes.
• Identify surface features caused by constructive processes.
• Deposition (Deltas, sand dunes, etc.)
• Earthquakes
• Volcanoes
• Faults
Essential Question: How do
constructive forces change the
Earth’s surface?

3. What is a constructive force?
• A constructive force is a process that raises or
builds up the surface features of the Earth.
– Examples are:
• Deposition- (sand dunes, delta, sea shells)
• Earthquakes
• Volcanoes
• Faults

4. Deposition
• Deposition is the dropping or depositing of
sediment by water, wind, or ice.
• Deposition builds up new land on Earth’s
surface, like a delta at the end of a river or a
sand dune built by the piling up of sand.
• Sea shells on the beach are an example of
deposition.

5. Sand Dunes

6. Deltas
• A delta is a landform that is formed at the
mouth of a river.

8. Earthquakes
• Earthquakes are vibrations on Earth’s surface
caused by sudden movement on Earth, often
along a fault, a break in the Earth’s surface.
• Large earthquakes can cause landslides and
tsunamis.
http://www.brainpop.com/science/earthsystem/earthquakes/

10. Fault Lines
• A fault line is a break or fracture
in the ground that occurs when
the Earth's tectonic plates move
or shift and are areas where
earthquakes are likely to occur.

13. Volcanoes
• Volcanoes are mountains with an opening in the
Earth’s crust.
• Magma, gases, and ash come through the
opening to reach Earth’s surface.
• When the magma erupts from the volcanoes, the
top of the mountain can be changed. The top of
the mountain can get larger or explode off.
• The ash and lava can destroy forests and farms.
http://www.brainpop.com/science/earthsystem/volcanoes/