1. INTERNAL AND EXTERNAL FORCES ON THE EARTH’S SURFACE

3. SLIDE 3 FOR MILLIONS OF YEARS THE SURFACE OF THE EARTH HAS BEEN IN SLOW BUT CONSTANT MOVEMENT. THE FORCES THAT CAUSE THIS MOVEMENT ARE INTERNAL AND EXTERNAL FORCES. INTERNAL FORCES WORK BELOW THE EARTH’S SURFACE VOLCANISM AND MOVEMENTS THAT BEND, FOLD OR LIFT THE CRUST EXTERNAL FORCES WORK ON THE EARTH’S SURFACE WEATHERING AND EROSION IT IS ON THE OUTER LAYER OR CRUST OF THE EARTH WHERE LANDFORMS DEVELOP THAT ARE CREATED BY THESE INTERNAL OR EXTERNAL FORCES.

4. SLIDE 4 AT ONE TIME THE CONTINENTS WERE ALL JOINED AS ONE
SLIDE 4 AT ONE TIME THE CONTINENTS WERE ALL JOINED AS ONE. THIS WAS PANGEA. SLOWLY THEY DRIFTED TO THE POSITION THEY ARE TODAY AND ARE STILL MOVING. THIS IS CALLED CONTINENTAL DRIFT AND WAS PROPOSED IN THE 1930S. IT WAS NOT PROVEN UNTIL THE 1970S. CLICK : TODAY IT IS CALLED PLATE TECTONICS. HOW DO WE KNOW PLATES ARE MOVING???

7. CONTINENTS MOVE DUE TO THE PLATES MOVING

8. INTERACTIVE WEBSITE
GO TO THE FOLLOWING WEBSITE BY CLICKING ON THE LINK.

9. THE CONTINENTS MOVE BECAUSE THEY ARE ON PLATES THAT FLOAT ON THE EARTH’S MANTLE. THERE ARE 12 OF THESE PLATES THERE ARE 4 TYPES OF MOVEMENT ALONG PLATE BOUNDARIES : PLATES MOVING AWAY FROM EACH OTHER WHICH IS CALLED RIFTING OR DIVERGING PLATES EXAMPLES- MID-ATLANTIC RIDGE, RIFT VALLEY IN AFRICA PLATES CONVERGING OR COLLIDING ( A. ONE PLATE GOING UNDER ANOTHER – SUBDUCTION. THIS IS AN OCEAN PLATE GOING UNDER A CONTINENTAL PLATE VOLCANOES AND EARTHQUAKES FORM ALONG THE BOUNDARIES EXAMPLES: ANDES, CASCADE RANGE TWO OCEAN PLATES COLLIDING ( SUBDUCTION) ISLAND ARCS ARE FORMED – PHILIPPINES TWO CONTINENTAL PLATES CONVERGING THIS IS THE SAME AS #2 BUT INVOLVES 2 CONTINENTAL PLATES RATHER THAN OCEAN AND COMNTINENTAL EXAMPLES: ROCKIES AND ALPS-FOLDED MTS APPALACHIANS PLATES SLIDING PAST EACH OTHER- FAULTING CALLED TRANSFORM PLATES.

10. 1.RIFTING OR SPREADING or DIVERGING
PLATES MOVING AWAY FROM EACH OTHER
WHICH IS CALLED SPREADING OR RIFTING OR
DIVERGING.
EXAMPLES- MID ATLANTIC RIDGE, RIFT VALLEY IN AFRICA.

12. MID-ATLANTIC RIDGE

13. 2. COLLIDING OR CONVERGING PLATES A
2. COLLIDING OR CONVERGING PLATES A. SUBDUCTION ONE PLATE GOES UNDER ANOTHER Example: ONE OCEAN AND ONE CONTINENTAL VOLCANIC MOUNTAINS ARE FORMED

15. B. SUBDUCTION ONE PLATE GOES UNDER ANOTHER EXAMPLE : TWO OCEAN PLATES VOLCANIC ISLAND ARCS ARE FORMED

17. 3. CONVERGING OF TWO CONTINENTAL PLATES TWO CONTINENTAL PLATES COLLIDING EXAMPLE: ROCKIE MTS, ALPS, HIMALAYAS APPALACHIANS

19. 4. FAULTING PLATES SLIDING PAST EACH OTHER THESE ARE CALLED TRANSFORM PLATES.

21. SLIDE 21 INTERACTIVE WEBSITE
GO TO THE FOLLOWING WEBSITE BY CLICKING ON THE LINK.

24. SLIDE 24 INTERACTIVE WEBSITE
CLICK ON THE FOLLOWING WEBSITE:
THEN GO TOP THE TOPIC EARTHQUAKES, TECTONIC PLATES AND VOLCANOES.

25. EXTERNAL FORCES THESE FORCES WORK ON THE LANDFORMS THAT ARE CREATED BY INTERNAL FORCES. NEW LANDFORMS CAN ALSO BE CREATED BY THESE EXTERNAL FORCES. THERE ARE TWO TYPES OF EXTERNAL FORCES WEATHERIN G AND EROSION THAT CAN ALTER THE SIZE AND SHAPE OF LANDFORMS.

26. 1.WEATHERING BREAKDOWN OF ROCKS AT OR NEAR THE EARTH’S SURFACE 2 TYPES: PHYSICAL AND CHEMICAL
TREE ROOTS
2. FREEZE AND THAW CYCLE

27. EXAMPLES OF PHYSICAL WEATHERING
CHECKERBOARD MESA – UTAH
ZION CANYON
LONE CYPRESS –CALIFORNIA
17 MILE DRIVE
BRYCE CANYON

28. B. CHEMICAL WEATHERING 1. CHEMICALS IN WATER DISSOLVE ROCKS.
( CARBONATION)
2. CHEMICALS IN AIR AFFECT ROCKS.
( OXIDATION)
WITH CHEMICAL WEATHERING ROCKS CHANGE THEIR COMPOSITION!!

29. EXAMPLES OF CHEMICAL WEATHERING
CARBONATION
OXIDATION
BRYCE CANYON -UTAH
WEEPING ROCK - ZION

30. 2. EROSION THE MOVEMENT OF WEATHERED MATERIAL SUCH AS GRAVEL, SAND AND SOIL.
THERE ARE 3 TYPES OF EROSION :
WATER
B. WIND
C. GLACIERS

31. 1. WATER - WEARS AWAY CREATING CANYONS
GRAND CANYON
ZION CANYON
ERODES AWAY CANYONS AND VALLEYS

32. WATER 2.TRANSPORTS PARTICLES AND CREATES DELTAS AND BEACHES
NIGER DELTA

33. WIND 1. WEARS SURFACE DOWN
ARCHES
BRYCE CANYON

34. WIND 2. CREATES NEW LANDFORMS LIKE SAND DUNES
EGYPT
LAKE MICHIGAN

35. GLACIERS 1. SHEET 2. MOUNTAIN