Learner Outcomes
By completing these activities, the learner will:
Consider the locations of earthquakes and volcanoes around the world.
How are the locations alike and different?
Many volcanoes and earthquakes surround the Pacific Ocean. This ring is often called the Ring of Fire.
Would you rather experience an earthquake or a volcano? Why?
Could earthquakes cause volcanoes? Could volcanoes cause earthquakes?
Concept Introduction
The planet we live on is made up of layers.
The inner-most layer is called the core. The core is very hot and made up of the heavy elements of Nickel and Iron.
The middle layer is called the mantle. The mantle is made of a squishy substance something like wet modeling clay.
The outer-most layer is called the crust. This very thin layer in only 6 - 10 miles deep. It is thinnest under the oceans and deepest under the mountains.
The Interior of the Earth
The center of the Earth is much too deep to study by digging holes. The center is more than 3,000 miles away. However, by studying earthquakes, scientists have figured out what the inside of the Earth is like. Using supercomputer models, scientists have developed a detailed picture of the interior of the Earth.
Concept Application
A most exciting concept is that the crust is made of about nine large sections, called plates, that slide against, across, and under each other.
Earthquakes and volcanoes outline the edge of the plates.
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1. Human Plate Tectonics Statue
a. Each person represents a plate of the earth's crust. One by one,
students begin to make a "plate statue" by freezing in a position at a
designated spot in the room. They are to stand very close to another, but
not touching.
b. Once the entire class has formed the plate-statue, give directions
for students to move slightly but without touching anyone else.
c. Now have students touch hands with another plate (student) and bump softly. What happens?
d. This is the idea of what happens when you have an earthquake. The rough edges of moving plates jump as they slide past one another.
e. What happens when plates bump or slide roughly?
2. Human Seismograph
b. Tape a large piece of paper to a table or desk.
c. As you try to slowly draw a straight line, have a fellow student shake the table.
d. How does the intensity of the shake or bump relate to the how "un-straight" the line is?
e. Look at a "live" seismograph in California (old images). Would it look different if there was an earthquake occuring in California right now? How would it look different?
f. Scientists use a Richter Scale or the Modified Mercali Scale to rate how big an earthquake is. The larger the number, or magnitude, the more the ground moves. Earthquakes with a magnitude of 1 have much less energy than an earthquake the measures 5. The Richter scale was developed to describe the intensity of earthquakes. How big was the most recent earthquake this week?
g. Form the Human Plate Tectonics Status again. Note the way the plates are near each other but don't touch. Choose volunteers to come from inside the plate statue and try to escape through holes in the plates. These areas are places where magma (the hot molten liquid found beneath the surface) can escape through earth's crust. Melted rock beneath the Earth's surface is called magma. When melted rock comes to to the surface, it is called lava. When this happens, it is called a volcano.
Edible Model of The Earth's Interior- Students enjoy learning about the three main parts of the earth by making an edible earth and eating it.
First take a red hot candy, which represents the core of the earth and squeeze it into the center of a marsmallow, which represents the mantle. Then take the filled marshmallow, stick a toothpick in it, and plunge it into melted chocolate. Use a crock pot to melt the chocolate, which hardens as it cools to become the thin crust of the earth. Place the chocolate covered marshmallow on wax paper to harden. Then eat.
Compare the picture of earth's layers to your marshmallow. You can see how the earth and marshmallow are similar. They both have a center core that is red hot. The middle is also mushy and soft just like the material that makes up the earth's mantle. The thin outside layer around the marshmallow was a hot liquid but became became a thin solid surface when it cooled just like the earth's crust.
Assessment: Students draw a picture of the earth's layers and label the core, mantle, and crust.
