1. Processes that Shape the Earth
Earth’s Systems
Processes that Shape the Earth

2. Plate Tectonics The earth is made up of 4 layers: -crust -mantle
-outer core
-inner core.
The crust is the outside of the earth. This is the part that we stand on.
The mantle is the second layer of the earth. It makes up about 84% of the Earth’s volume. The mantle is mostly solid rock, but it is so hot that it can melt the rocks to make magma.
The outer core is the third layer of the earth. It is mainly made up of liquid iron (an element that is used to make steel).
The inner core is the fourth layer of the earth. It is the hottest part of the Earth and is approximately 5430 °C (about the same temperature as the sun!)

3. Plate Tectonics -8 plates -Plates move to create continents.
-Plates are in the lithosphere.
-Plates are always moving slowly.
The Earth consists of 8 floating plates. The movements of these plates help shape the Earth. The plates used to be connected to create Pangea. The lithosphere is the crust of the Earth; the earth we stand on.
continent: A major piece of land on Earth
left: pangea
right: the 8 plates on a map

4. Plate Tectonics
When the plates move, they interact with each other. There are 3 different types of plate interactions:
-diverging
-converging
-transform
Diverging and converging plates form volcanoes mountains
All three boundaries cause earthquakes.

5. Plate Tectonics Diverging - the plates move away from each other
Converging - the plates move together
Transform - plates slide
past each other
-Diverging plates help shape by allowing magma to seep through the two plates. When this happens, the magma cools to form new parts of the crust.
-converging plates can form mountains and volcanoes when subduction zones occur (next slide).
-transform plates often cause earthquakes which can change the surface of the earth. (explained in video)

6. Subduction Zones Subduction Zones are when one plate goes underneath
another plate.
This happens when two plates converge.
- subduction zones shape the earth by forming mountains and volcanoes. When a plate subducts, it can push the other plate up to form mountains and volcanoes.
-to demonstrate to kids: have them make two fists and have them push their fists together until one of them goes underneath the other. This represents subduction zones.

7. Volcanoes There are many different types of volcanoes that help
make the earth’s crust:
-shield
-composite
-cinder cone
Volcanoes are mountains that spill lava from the Earth’s mantle. Recall previous lesson: volcanoes are formed by convergent and divergent plate boundaries. Each of these volcanoes act in different ways that help create the Earth’s crust and each have different explosions. Shield volcanoes are flat and round. Instead of erupting like other volcanoes, this volcano oozes out lava. The composite volcano sometimes known as the stratovolcano is known to be explosive and is the largest of the volcanoes growing up to 8,000 feet and has large steep slopes. Lasty, there is the cinder cone volcano which also is explosive. The volcano usually looks like a slope with straight sides and is medium sized.
Top right: shield volcano
Bottom right: composite volcano
Bottom left: shield volcano

8. Volcanoes
Lava from volcanoes starts as magma inside the asthenosphere.
Magma is molten rock that is inside the Earth. Magma becomes lava when it reaches the surface.
asthenosphere - the part of the mantle that contains some magma.
One example is Hawaii formed when the hot lava mixed with the cold water of the ocean.
use link as an example (lilo and stitch the series explaining formation of islands) 24: :00

9. Erosion
Erosion is when things rub together and form different shapes. There are:
-wind erosion rock erosion
-water erosion
-ice erosion
Erosion can be caused by wind, water, or ice. Wind causes erosion by blowing small particles across the surface of the rock,slowly wearing it down. One example is the desert. There are no large rocks in the desert because of the constant wind blowing sand around. Water erosion can carve canyons such as the Grand Canyon. Ice erosion can occur when glaciers gather sand on their sand and rub against rocks or other glaciers.

10. Weathering
Weathering is the breaking down of rocks and materials. The types of weathering are:
-physical weathering
-chemical weathering
-biological process.
weathering: physical, chemical, and biological processes that break down rocks and minerals
physical weathering/mechanical weathering: when rocks break down but do not change chemically i.e. wind and rain
chemical weathering: when substances interact with the rock to break it down. i.e. acid rain changing how statues look
biological processes: when living organisms break down material. i.e. a tree root breaking apart the sidewalk

11. Wind/Water Erosion Prevention
Wind and water erosion can damage soil. Wind and water brings soil with them when they pass by.
Wind and water erosion can cause huge destruction to land and its ability to sustain life. Erosion can seep into lakes or rivers and cause problems with the water. Also, with erosion the land will lose some nutrients, matter, and its structure that it previously needed to sustain life.

12. Wind/Water Erosion Prevention
There are many ways to stop this though. Some ways of stopping erosion are:
-planting plants
-building a dam
-using mulch rubble
-having tall plants.

13. Wind/Water Erosion Prevention
Building barriers stop the erosion from moving out of control.
Barriers stop erosion by preventing the soil from moving.

14. Wind/Water Erosion Prevention
-Tall plants protect small plants.
-Mulch holds soil under plants.
-Roots take up water and keep soil still.
Mulch is like the material you can find on the playground floor. (wood chips)