Earth is a planet which is in constant motion and change Unit E Planet Earth Section 3.0-3.3 Earth is a planet which is in constant motion and change

Section 3.1 Continental Drift Facts In 1910 a German scientist Alfred Wegener noticed that the shapes of the continents seemed to fit together He developed a theory that at one time the continents had been joined together forming a single land mass called: “PANGAEA” (all lands) Since the time of Pangaea, the continents have drifted apart, known today as “CONTINENTAL DRIFT”

How Could Wegener Prove It!!!! He studied the rock formations from the separated continents Examined land formations (mountains) He even looked at the possibility of tropical regions previously subsiding in the polar regions ** In the 1960’s Wegener’s ideas finally took off and came to enter the world of science

Section 3.2 Plate Tectonics Through various types of technology when scientists plotted specific features of the Earth (mountains, ocean valleys, earthquakes and volcanoes) a certain pattern emerged. Earthquakes and Volcanic Eruptions were occurring in the same place. WHY?? There are deep valleys under the ocean floor near the edges of the continents where PANGAEA split.

MID-ATLANTIC RIGDE Vocabulary Trenches: deep valleys under the ocean floor Ridges: mountain like chains rising above the ocean floor What Area Do You Need to Know? MID-ATLANTIC RIGDE This led to the theory of seafloor spreading or “Continental Drift”

The Theory of Plate Tectonics The Theory states: The lithosphere is broken up into large pieces much like a puzzle called “PLATES” Each plate carries either a continental (land) or an oceanic piece Vocabulary Boundary: edge where plates meet Diverging Boundary: where two of the Earth’s plates move apart Example: lava will flow from the ridge to form new oceanic crust as well as growing high enough to be seen

2 Types of Converging Boundaries 3. Converging Boundaries: plates are moving toward each other Because these plates are large they move very slowly, therefore when they collide the effects are huge 2 Types of Converging Boundaries Trench Forms – one plate carries heavier/thinner oceanic crust, the other plate is lighter/thicker continental crusts This is known as “SUBDUCTION” Continental Push – two plates with continental crust move up against each other, therefore forming a mountain 4. Transform Boundaries: plates slide sideways past one another, however it is not smooth, this is because the rocks either bind or catch on each other causing an earthquake

“Do Now” Try to list the different types of boundaries involved in plate tectonics.

Section 3.3 Mountain Building What is Mountain Building Vocabulary Mountain: part of the Earth’s surface which tends to be much higher than the land around it Mountain Range: series of mountains (i.e. Rocky Mountains, extending from the Yukon through to the US and into parts of Mexico) Mountain Building: process by which the mountains are created Activity Time Read An Alberta Story pg. 403 Summarize using your own words important facts you read in the story

What is the Difference between a Fold and a Fault Mountain?? FOLDED ROCK Sedimentary rock under slow, gradual pressure can fold (bend like plastic because they are made soft by the heat) or break and change to metamorphic rock The upward, or top part of folded rock is called ANTICLINE The bottom fold is called SYNCLINE When older rock ends up on top of younger rock, the result is the formation of fault Block Mountains.

Where Does Folding Happen FAULTED ROCK The place where the crack or break occurs is called “fault” and is often below the surface of the Earth. Draw & Label (pg. 405) Figure 3.20 & 3.21 Where Does Folding Happen Because rocks are hard they can only fold after they have been heated or pressure is put on them This is when the Theory of Plate Tectonics play a major factor, because colliding plates provide the heat and pressure therefore softening the rocks As the rocks push together they wrinkle and fold upward

Assess Your Learning (pg.409) Homework Assess Your Learning (pg.409) Questions #1 to 8