Chapter 2 – 2 Forces Chapter 2 – 2 Forces Shaping EarthShaping Earth

World GeographyWorld Geography

Review From YesterdayReview From Yesterday

What do you remember about the What do you remember about the revolution of the earth?revolution of the earth?

What do you remember about days What do you remember about days and nights?and nights?

How does latitude affect the seasons?How does latitude affect the seasons?

On a ½ piece of paperOn a ½ piece of paper

Online Latitude QuizOnline Latitude Quiz

Not graded but do you must do your Not graded but do you must do your best!best!

Today, you will learn…Today, you will learn…

Today you will be learning about the Today you will be learning about the forces that shape our planet Earth, forces that shape our planet Earth, both inside and out.both inside and out.

You will also learn about the different You will also learn about the different layers that make up the earth.layers that make up the earth.

What exactly is plate tectonics? What exactly is plate tectonics?

The Pacific Ring of FireThe Pacific Ring of Fire

This is a great example of the forces that are currently shaping our planet earth.

What does the earth look like What does the earth look like on the inside?on the inside?

An easy way to think of An easy way to think of the inside of the earth is the inside of the earth is to imagine that the to imagine that the earth is a giant earth is a giant gobstopper with many gobstopper with many different layers, flavors, different layers, flavors, and colors. and colors.

A) Earth’s LayersA) Earth’s Layers

1) The 1) The corecore is a sphere of very is a sphere of very hot metal at the center of the hot metal at the center of the earth. earth.

2) The 2) The mantlemantle is a thick, hot, is a thick, hot, rocky layer surrounding the rocky layer surrounding the core. core.

3) The 3) The crustcrust is the thin layer of is the thin layer of rocks, and minerals that rocks, and minerals that surround and float on the surround and float on the mantle. mantle.

Layers of Layers of Inner Inner EarthEarth

B) WaterB) Water

1) 70% of the 1) 70% of the earth’s surface is earth’s surface is water water

Lakes, rivers, seas, Lakes, rivers, seas, oceans. oceans.

30% is land30% is land

2) 97% of water is 2) 97% of water is in oceansin oceans

3% of world 3% of world freshwater. freshwater.

Get Get it?it?

C) Forces Inside EarthC) Forces Inside Earth

1) Heat deep inside 1) Heat deep inside Earth is constantly Earth is constantly reshaping the reshaping the planetplanet

2) The earth is 2) The earth is made up of moving made up of moving plates of land that plates of land that “float” on magma. “float” on magma. Just like boiling

water, magma bubbles to the surface of the earth

Earth’s Earth’s Moving Moving Tectonic Tectonic Plates Plates

Through TimeThrough TimeBilions of years ago, all continents were connected in a supercontinent named Pangea

WebsiteWebsite

Pangea WebsitePangea Website

D) Volcanoes and D) Volcanoes and EarthquakesEarthquakes

1) Volcanoes are 1) Volcanoes are formed by two formed by two tectonic plates tectonic plates colliding and one plate colliding and one plate sliding under another sliding under another plate. plate.

2) Earthquakes are 2) Earthquakes are caused when two caused when two plates push into each plates push into each other. other.

World Seismicity 1978 - World Seismicity 1978 - 19871987

Notice how all earthquakes have occurred along plate boundaries!

E) Forces on Earth’s SurfaceE) Forces on Earth’s Surface

Forces inside the earth Forces inside the earth create. create.

Forces on the outer part Forces on the outer part of the earth wear earth of the earth wear earth down and reshape it. down and reshape it.

1) 1) WeatheringWeathering is a is a process that breaks process that breaks rocks down into tiny rocks down into tiny pieces. pieces.

2) 2) ErosionErosion is the is the removal of small pieces removal of small pieces of rock by water, ice of rock by water, ice and wind. and wind.

WebsiteWebsite

Layers of the Earth Website - CNNLayers of the Earth Website - CNN