Everybody Read to Find Out: How the layers of the earth are ordered and what the names of the layers are.

Everybody Read to Find Out:

•How the layers of the earth are ordered and what the names of the layers are

1. The center of the earth consists of hot rock and is called the inner core (solid iron and nickel).

2. There is also an outer core (liquid iron and nickel).

3. The next level is hot, molten rock called mantle.

4. The layer that we walk on is the crust.

1. The Crust1.The earth’s outer layer of

rock2.5-20 MILES THICK!!3.Has mountains, ocean

floor, volcanoes, and continents

2. The Mantle1. The second layer between the

crust and outer core2. Is solid rock except for the

part next to the crust, where there is thick liquid

3. 1,800 MILES THICK!!

3. The Outer Core1. The outer part of the core is

liquid and HOT!2. It gets hotter the deeper you

go (around 9,000 degrees F in the center—your oven only goes to about 600 degrees F).

3. It’s so hot that rock melts. Melted rock is called MAGMA.

4. 1,400 MILES THICK!

4. The Inner Core1. 800 MILES TO CENTER!2. Shaped like a ball, or sphere.3. Solid

Everybody read to find out:

1. What makes the earth’s crust move

2. The definition of plate tectonics

3. What forces act on Earth’s crust

(P. C-18-C-21)

The inside of the earth is very hot, and it always releases a lot of energy.

This energy causes things to move in the earth (rocks, plates, etc.)

The earth has many different landforms. They include mountains, hills, rivers, canyons, plateaus, and many other things.

CauseEffects

Plate Tectonics1. Plate Tectonics

a. Explains how plates (large bodies of rock) move slowly around the earth on partly melted rock

2. Platesa. A large section of the earth’s crust that moves as one unitb. There are 8 large plates and several smaller plates.

Plate TectonicsAs these plates float, they move in

three different ways. Each way that they move has a special name associated with the boundary where two plates meet.

Fault -- the place where two plates meet.Types of plate movement:

1. Convergent -- where two plates move together

2. Divergent – where two plates are drifting apart.

3. Sliding – where the plates slide past one another.

Already knew

New Info Wow!

Wonder?

•Layers of Earth•There are 7 continents.•Earth’s plates move in 3 ways (convergent, divergent, & sliding).•Plate Tectonics Theory says that Earth is made up of plates.

•Alfred Wegener thought up the Continental Drift Theory.•The CD Theory is that the continents move together and then away from each other.•Also, he thought the continents were all joined once.

•Wegener named the huge continent Pangaea.•The Mid-Atlantic Ridge is a HUGE mountain range on the ocean floor (10,000 feet).

•It is crazy to think that plants moved with the land mass.•Will we ever see big changes in Earth?

Volcanoes1. What are they?

a. An opening in the earth’s surface.

2. How do they form?a. Magma (melted rock) from the mantle sometimes pushes

upward.b. The crust usually blocks it, but sometimes it seeps through cracks

in the crust. When it builds up inside a “magma chamber”, the pressure

starts to increase and then---BAM!!!

3. What happens after they erupt?a. The magma explodes through a

main vent in the volcano.b. A deep hole called a crater is often

left on top of the volcano.c. The erupting magma is called lava.d. Gases, volcanic bombs, ash, and

melted rock also burst from inside the volcano.

e. The lava layers and ash layers build up around the outside of the volcano.

4. Interesting Facts:a. Hawaii was formed by volcanoeserupting in the Pacific Ocean.b. The two types of volcanoes are

erupting and oozing.c. Lava can flow up to 50 mph but

usually just flows 10 mph.

Connecting Learning1. Do you think Pangaea once existed?

Why or why not?2. Use the diagram on p. 21. In which

direction does each of the continents seem to be moving? How might Earth look several million years from now?

3. Look at the map of the earthquakes and volcanoes and Earth’s plates (p. 22). What do you notice?

4. What are you wondering now?

Earthquakes1. What causes earthquakes?

a. Sudden shifts in the earth’s rock layers cause earthquakes

2. The focus, or epicenter, is where the earthquake begins.

3. During an earthquake, the plates might:a. Meet in a rubbing way (shoulder

to shoulder)--slidingb. Spread away from each other

(divergent)c. Meet in a pushing way

(subduction)-- convergent

4. New plates can be created during an earthquake (especially at mid-ocean ridges).

5. A seismograph is used to measure earthquakes.

a. The Richter scale is used to give them a number.

b. People cannot feel earthquakes between a 1-2 on the scale.

c. An earthquake that receives a 7-8 destroys buildings.

6. Earthquakesa. Shake and destroy land,

homes, and buildingsb. Create land by creating

mountains and valleys

3 Different Types of RocksScientists classify rocks in 3 main groups

based on how they were formed.1. Igneous Rocks (Fact: Igneous means “fiery”)

a. How they form: When magma reaches the surface, it becomes lava.

b. This hot, molten rock cools and hardens to form igneous rock.

c. Characteristics: Igneous rocks vary in size, shape, color, and

texture. Examples: basalt, pumice, obsidian

2. Sedimentary Rocksa. Form in water from

“sediment”, which is grains and bits of rock that were created by erosion or weathering.

b. Fact: The sediment builds up over many years and becomes cemented together to form sedimentary rock.

c. Characteristics: These rocks are layered. The layers tell the story

about how the rock was formed. They can also have fossils, which tell a story, too!

d. Examples: sandstone, limestone, shale, and conglomerate

3. Metamorphic Rocks (means “change”)a. Formed from another rock by

heat and pressure. b. Usually form beneath the earth’s crust (which means

they often heat up and become magma again—it’s a cycle—the Rock Cycle!)

c. Fact: Both igneous and sedimentary rocks can

change into metamorphic rocks.d. Characteristics: These rocks

are usually harder than the rocks that they were at first.

e. They may have “bands” which look like stripes or layers from different minerals pressed together by the heat and pressure.

Examples:

gneiss, s

late,

schist

Rocks and Minerals

1. Minerals are made up of elements and compounds.

2. Rocks are made up of minerals.3. As minerals form, their atoms and

molecules form patterns that are crystal shapes.

4. Scientists identify minerals by:1. luster (how light bounces off

of it)2. streak (color of powder left

when a mineral is rubbed against a surface)

3. hardness (Moh’s Hardness Scale)

4. cleavage (how a mineral breaks apart)

5. density6. color

Weathering and Erosion1. Physical (mechanical) weathering happens

when the earth’s crust is exposed to water, air, and changes in temperature.

a. Rocks can wear away, making smaller rock pieces, or

sediments.b. Freezing water expands, or

takes up more space and can cause rocks to crack.

2. Chemical weathering happens when gases in the air chemically react with other elements and minerals.

a. Acid rain can dissolve limestone rocks.

3. Erosiona. Is the carrying away of weathered rock by gravity,

water, wind, and iceb. Erosion can wash away

boulders and mountains!

Examples: soil washed onto the sidewalk, crumbling rocks on buildings, holes in the road, cracked sidewalks, plants/roots growing by sidewalks, muddy streams

Examples of Erosion and Weathering

• Sea cliffs form when a rocky shore erodes at approximately the same rate throughout an area. This results in a steep walled structure. The cliff moves landward as the waves attack its base.

Examples of Erosion and Weathering

• A gully caused by severe rainstorms.