3.1

Earth’s Interior

Ms. De Los Rios

7th Grade

Earth’s Structure and Materials

Vocabulary 3.1

1. Seismic Waves- Vibrations that travel through Earth carrying the energy released during an earthquake.

2. Pressure- The force pushing on a surface divided by the area of that surface.

3. Crust The layer of rock that forms Earth’s outer surface.

4. Basalt- A dark, dense, igneous rock with a fine texture, found in oceanic crust.

5. Granite- A usually light-colored igneous rock that is found in continental crust.

6. Mantle- The layer of hot, solid material between Earth’s crust and core.

7. Lithosphere- A rigid layer made up of the uppermost part of the mantle and the crust.

8. Asthenosphere- the soft layer of the mantle on which the lithosphere floats.

9. Outer core- a layer of molten iron and nickel that surrounds the inner core of Earth.

10.Inner Core- a dense sphere of solid iron and nickel at the center of Earth.

How Do Geologists Learn About Earth’s Interior? Pgs. 98-99

Geologists have used 2 main types of evidence to learn about Earth’s interior:

1. Direct Evidence From Rock Samples

2. Indirect Evidence From Seismic Waves.

1. Evidence From Rock Samples

•Geologists have drilled holes as deep as 12.3 kilometers into Earth.

•The drills bring up samples of rock.

•These rocks give geologists clues about Earth’s structure and conditions deep inside Earth.

 

Example of a cylindrical whole rock core.  

2. Evidence From Seismic WavesWhen earthquakes occur they produce seismic waves.

Geologists record the seismic waves and study how they travel through Earth.

Infer: Geologists have found that the paths of seismic waves change When the waves reach specific depths Inside Earth.

What can you infer about the Earth’s structure from this Observation?

_____________________________________________________________________________________________

Paths of the ocean waves

change when the waves reach an island.

Paths of ocean waves change when the waves reach an island.

Assess Your Understanding

I get it! Now I know that, to learn about Earth’s Interior, Geologists use two main types of evidence:_____________________________________________________________________________________________________________________________

What Are The Features of Earth’s Crust, Mantle, and Core? Pg. 100

the crust

The three main layers of Earth are: the mantle,

the core.

These layers vary greatly in size, composition, temperature, and pressure.

Pressure results from a force pressing on an area.

The Deeper Down Inside Earth,

The Greater the Pressure and the greater the Temperature!

Earth’s Crust pg. 101

Earth’s crust is the layer of rock that forms Earth’s outer skin.

•The crust is a layer of solid rock that includes both dry land and the ocean floor.

•The composition of oceanic crust is much like basalt- a dark rock that has fine grains.

•The composition of continental crust is much like granite- a rock that usually is a light color and has coarse grains.

Earth’s Mantle pg. 102

Earth’s Mantle Is the solid material of the mantle is a layer of

hot rock.

•Earth’s mantle is made of rock that is very hot, but solid.

•Overall, the mantle is nearly 3,000 kilometers thick.

•Scientists divide the mantle into layers based on the physical characteristics of those layers.

Mantle’s Layers

Layers•the Lithosphere is the crust and uppermost mantle.

•Just beneath the lithosphere the Asthenosphere- Is the soft layer.

•Beneath is a layer called the Mesosphere- which is hot but more rigid.

Earth’s Core pg. 103

The core is made mostly of the metals iron and nickel.

The Core consists of 2 parts:

1. a liquid outer core- The outer core is a layer of molten metal surrounding the inner core.

2.a solid inner core- The inner core is a dense ball of solid metal.

Scientists think that movements in the liquid outer core create Earth’s magnetic field

Figure 2 Pressure and Depth

The deeper that this swimmer goes, the greater the pressure from the surrounding water. Compare and Contrast:

How is the water in the pool similar to Earth’s Interior? How is it Different? (Hint: Consider both temperature and pressure in your answer.)

Depth0

0.5m

1 m pressure increases 1.5 m

Earth’s Crust- the crust is the Earth’s Outer Layer of Solid Rock.

The circle graph shows the composition of Earth’s crust.

1.Read Graphs In Total, How much Of Earth’s crust is made up of Oxygen and Silicon?________________________

2. Summarize Fill in the missing Information in the two charts.

Oceanic crustTypical rock: ________________Relative Grain Size: ___________Color: ______________

Continental CrustTypical rock: ________________Relative Grain Size: ___________Color: ______________

The Earth’s Crust – fig. 3 pg. 101

Earth’s mantle is nearly 3,000 kilometers thick. The rigid lithosphere rests on the softer material of the asthenosphere. Describe Earth’s Layers by filling in the boxes next to the diagram of the upper mantle.

The Mantle pg. 102

The Core of ItEarth’s core consists of two separate layers.Where do these terms go on the Venn diagram?

The Core – Fig. 5 pg. 103

The graph shows how temperatures change between Earth’s surface and the core.

1.Read Graphs:Between what depths doesEarth’s temperature increase the slowest?____________________________2. Challenge: Why does the graph show a temp. Of 16 C at 0 meters of depth?________________________________________________________

3. Interpret Data:How does temperature change with Depth in Earth’s Interior?________________________________________________________

Do the math! Temperature Inside Earth pg. 103

The Core and Earth’s Magnetic Field pg. 104

Scientists think that movements in the liquid outer core create Earth’s magnetic field.

Because Earth has a magnetic field, the planet acts like a giant bar magnet which has a North and South Pole. This affects the entire planet.

Identify Benefits:What is one benefit ofUsing a bar magnetAs a model of Earth’sMagnetic field?_______________________________________________________________

Assess Your Understanding pg. 105

1a. Identify: Earth’s thin outer layer of solid rock is called

(the crust / the mantle / the core.

b. Summarize: What is the structure of Earth?

_________________________________________________________________________________________________________________________________________________________

I get it! Now I know that each of the three main layers of Earth has its own features, as follows:

_________________________________________________________________________________________________________________________________________________________

What is the Structure of the Earth?Figure 7 pg. 104

1. Describe: Draw each of the Earth’s Layers. Include both the outer and inner core. Label each layer. Then, fill in the chart below.

Thickness/Radius Composition Solid/LiquidCrust_________________________________________________________

Mantle________________________________________________________

Outer Core_____________________________________________________

Inner Core_____________________________________________________

TOTAL 6,371 km

2. Compare and Contrast: Pick any two points inside Earth and label them A and B. Compare and Contrast Earth at those two points.

My Point A is in the ______________________________________________

My Point B is in the ______________________________________________

________________________________________________________________________________________________________________________