Our Changing Earth

Our Changing EarthBy Diana Thomas Topaz Elementary School1Our earth is always changing.Some changes are S L O W Some changes are FAST2Scientists think that the surface of the earth has been slowly changing for millions of years.This is the called the theory of

3Continental drift.

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5Glaciers can also slowly change the surface of the earth.

6Some changes to the earth happen Rapidly7Landslides

8Mudslides

9Moving Water

10Earthquakes

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12VolcanoesSome volcanoes change the earth quickly.Some volcanoes slowly build up the land over many, many years.

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15ReviewContinental drift is the theory of how continents move over Earths surface.

16Pangea was the Supercontinent on Earth millions of years ago before the continents drifted apart.

17Weathering is when rock is brokenup into smaller pieces called soil, sand, or sediment.Erosion is when the sediment is moved from one place to another.Deposition is when the sediment is dropped in a new place.18The surface of the earth can change slowly when... Lava comes out of a volcano and cools, building up into a mountain over time.

19The surface of the earth can change slowly when...

Glaciers (thick sheets of ice that stay frozen all the time) slowly move, carving the land as they go.20The surface of the earth can change slowly when... Water weathers rock as fast moving rivers carve deep canyons in the rock.

21The surface of the earth can change slowly when... Sediment is moved by water erosion and deposited in a new location. Deltas are made this way.

22The surface of the earth can change slowly when...

Water freezes in cracks of rocks. The freezing water expands, and the ice makes the cracks in the rocks bigger. Eventually the rocks break into small pieces.23The surface of the earth can change slowly when...

Wind carves away bits of rock like a sandblaster.

24The surface of the earth can change rapidly when... Volcanoes blast away the top or side of a mountain as it erupts.

25The surface of the earth can change rapidly when... two tectonic plates crash into or slide past each other. This causes an earthquake. Mountains and valleys can be made this way.

26The surface of the earth can change rapidly when... mass movement occurs. Landslides, mudslides, and sink holes all change the surface of the earth suddenly.

27Our earth is changing right now.

28Some of the graphics in this presentation may be copyrighted. This presentation is for educational use only.29