JOURNAL #6

What are the layers of the earth?

How is the earth unique?

CHAPTER 2Earth: A Unique Planet

TODAY’S LEARNING GOAL:

Today, we will Identify the 5 structural layers of the EarthDescribe why the Earth is unique

THE EARTH IS UNIQUE FOR SEVERAL REASONS: Only known planet that has liquid

water on it’s surface Only known planet that contains a

large proportion of oxygen in the atmosphere

Known to support lifeWhat is life?

EARTH BASICS Earth is about 4.6 Billions years old 71% of the surface is ocean Earth is an oblate spheroid Spinning of the earth on its axis makes

polar regions flatten

HOW DO SCIENTISTS KNOW THE COMPOSITION OF THE EARTH?

Direct observation is limited to a few kilometers (drilling)

Seismic waves are vibrations that travel through Earth.

Earthquakes and explosions near the surface produce seismic waves.

EARTH’S INTERIOR Crust- thin, solid, outermost layer

Makes up 1 % of the massOceanic crust – crust beneath oceansContinental crust- crust that makes up

continentsWhere is the continental crust the thickest?

Mantle – underlies the crust and is denser than the crustMakes up 2/3 of the Earth’s mass3 zones: lithosphere, asthenosphere,

mesosphere Core- center sphere composed of mainly iron

and nickel

EARTH AS A MAGNET Earth has 2 magnetic poles Earth’s magnetic field extends beyond

the atmosphere and affects a region of spaced called the magnetosphere.

LET’S REVIEW WHAT WE’VE LEARNED

What is the shape of the Earth?

Oblate spheroidName 2 characteristics that make Earth unique in our solar system

Liquid water on surface and Oxygen rich atmosphere

How do scientists learn about the Earth’s interior?

LET’S REVIEW WHAT WE’VE LEARNED

Seismic WavesWhat are the 3 Compositional layers of the Earth?

Crust, Mantle, Core

What are the 5 Structural Layers of the Earth?

LET’S REVIEW WHAT WE’VE LEARNED

Lithosphere Asthenosphere MesosphereOuter coreInner core