Earth's Structure and Atmosphere: Explore

Earth's Structure and Atmosphere: Explore

Identify and distinguish between the different compositional layers of the Earth

Describe the two main ways that scientists divide and describe the layers of Earth's interior

OBJECTIVES:

​VOCABULARY

• Chemical properties - Physical properties

• composition - seismic waves

• convection - structure

• core

• crust

• density

• lava

• mantle

Hotspot

Label the layers of the Earth.

Inner Core

Crust

Outer Core

Mantle

The compositional layers of the Earth are the crust, mantle, outer core, and inner core.

The crust and mantle can be further divided into layers based on their physical properties.
Physical properties are characteristics that are used to describe matter. Physical properties can be observed or measured without changing the composition of a substance. Some physical characteristics of Earth's layers include thickness, temperature, and whether it is a solid or a liquid.

​Earth's Physical Layers

What two compositional layers of Earth partially make up the physical layer known as the lithosphere?

Video

The lithosphere is the outermost physical layer of Earth and contains Earth's crust, as well as part of the upper mantle.

Lithosphere

Characteristics of the lithosphere:

- Outer layer, most rigid layer
- Made of solid rock
- Average thickness is 100 km
- Includes crust & solid uppermost part of mantle
- has a low density
- it is divided into pieces called tectonic plates

​

​Lithosphere

Tectonic Plates

Plates vary in volume, thickness, and density.
Continental crust is the part of the Earth's crust found under continents and tends to be thicker than oceanic crust which is found under oceans.

Plates move in three basic ways:

Two plates slide along beside each other.
Ex: San Andreas Fault, CA
-tends to create EQ

Strike-Slip

One plate slides under another. Tends to happen between continental and oceanic plates.
-tends to create EQ & Vol
Ex: Pacific plate and N. American plate (alaska)

Convergent Subduction

​Two plates move towards each other and crash into each other and push upwards.
tends to create Mtns
Ex: Himalayan Mtns

Convergent

Two plates move away from each other.
-tends to create Vol
Ex: Under ocean trench

Divergent

Characteristics:
- Thicker layer of mantle
- Rocks are semi-solid
- Temperature is not hot enough to make liquid rock but will melt rock to make magma
- Contains convection currents

​

​Asthenosphere

Characteristics:
- hotter than the asthenosphere

​- solid layer due to the pressure of layers above and gravitational pull of Earth keeps molecules from spreading out and rocks from melting

Mesosphere

Characteristics:
- layer of liquid metal (iron & nickel)
- very hot layer
- convection currents

​

Outer Core

Characteristics:
- solid ball of metal (nickel & iron)
- hottest part of the Earth's interior
- pressure and gravitational pull prevent inner core from melting

​

Inner Core

Scientists cannot drill deep down into either layer of Earth's core. Earth's core is more than 6,000 km below the crust. The temperature and pressure would destroy the drill.

​

Can we get to the core?

​Earth's Magnetic Field

-The physical property of the liquid outer core and the solid inner core helps to generate Earth's magnetic field.
-This magnetic field is why your compass needle points north.
-It also deflects harmful radiation from the Sun.

Watch Video of formation of magnetic field on Earth

Earth's Layers

Physical layer classification is useful when considering some observations.
EX: knowing how convection currents can move the tectonic plates

​Physical Layers

Help provide scientist with clues as to why the physical layers behave the way they do.

​Compositional Layers

Earth's layers

Lithosphere - solid top layer
Asthenosphere - more fluid
Mesosphere - hotter but rigid
Outer Core - liquid
Inner Core - Solid

Note: descriptions based on physical property

Physical

Crust - contain basalt and granite
Mantle - made mostly of silicate rock
Inner & Outer Core - made of iron and nickel

Note: descriptions based on what made of or chemical composition

​Compositional

Match

Match the following

• Lithosphere

• Inner Core

• Outer Core

• Mesosphere

• Asthenosphere

outer layer

solid rock

solid

contains nickel and iron

Liquid

contains nickel and iron

solid layer

cannot melt due to pressure

hot enough to soften rock

• outer layer

  solid rock

• solid

  contains nickel and iron

• Liquid

  contains nickel and iron

• solid layer

  cannot melt due to pressure

• hot enough to soften rock

Reorder

Reorder the following from INSIDE to OUTSIDE

• Inner Core

• Outer Core

• Mantle

• Crust

1

2

3

4

• 1
• 2
• 3
• 4

Match

Match the following

• Subduction

• Convergent

• Strike Slip/Transform

• Divergent

one plate going under another

create vol

two plates crash together

create mtn

two plates slide by each other

create EQ

two plates move away from each other

Vol

• one plate going under another

  create vol

• two plates crash together

  create mtn

• two plates slide by each other

  create EQ

• two plates move away from each other

  Vol