The document provides an overview of the Earth's structure and geological processes. It describes the three main layers of the Earth - crust, mantle, and core. It explains that the crust is made up of tectonic plates that are constantly moving due to convection currents in the mantle. When plates collide, converge, or move alongside each other, it causes volcanic activity and earthquakes. Major landforms like mountains and ocean trenches are formed by these plate tectonic processes. The document also discusses other geological forces like erosion and weathering that shape the Earth's surface over time.

1. The Earth
Chapter 2, Section 1

2. Section Objectives
• Analyze how processes deep within
the Earth affect its surface
• Identify major landforms and
analyze how they affect life on Earth
• Identify the causes of earthquakes
and volcanoes
• Understand the importance of
water and the hydrologic cycle.

3. Inside the Earth
• Earth has three layers:
- Crust
- 31 to 62 miles deep
- Thickest under continents; thinner below the oceans
- Mantle
- Layer of rock 1,800 miles thick!
- Outer mantle = sometimes melts, creating magma, or melted rock
- Inner mantle = solid
- Outer Core
- Mostly liquid; molten iron and nickel
- 1,400 miles thick
- Inner Core
- Solid iron due to pressure from above!
- 700 miles thick; reaches 12,000°F

4. Tectonic Plates
• Earth’s crust is divided into
sections called tectonic
plates:
– The earth’s crust consist of
plates, or huge slabs of rock,
that move
– Plates float on top of liquid
rock just below the crust
– Plates often move in different
directions
– Oceans and continents sit on
top of these gigantic plates!
Iceland, where the North American
plate meets the European plate

5. Plate Tectonics Map

6. Pangea
• Scientists believe
that long ago all
the continents were
joined together in a
land mass called
Pangea
• However,
eventually, the
continents drifted
apart - this is called
“continental drift”
– Bill Nye: Pangea & Plate

7. Pangea, cont.
• The plates are still moving today
– Plate under the Pacific moves west at 4”/year
– Plate along west edge of S. America moves east at
1.8”/year
• Some scientists believe that in another 250 million
years, the continents will be rejoined!

8. When Plates Meet
• Sometimes plates push against each
other, leading to one of four things
– Plates smashing into each other =
mountain ranges, like the Himalayas
– Thicker continent plate sliding over a
thinner ocean plate = volcanic
mountains, which erupt when pressure
between plates builds up
– Plates sliding alongside each other =
earthquakes along faults, or cracks in the
earth’s crust
– Plate movement along faults, like the San
Andreas Fault in California, can produce
damaging earthquakes and tsunamis, or
underwater earthquakes.

9. The Ring of Fire
• The Ring of Fire is a circle of
volcanoes and earthquakes
along the rim, or outer
edge of the Pacific Ocean.
• A large tectonic plate
under the ocean slides
against plates in the
surrounding continents.

10. Today’s Questions:
How does the movement of tectonic
plates impact landforms on earth?
What landforms are created?
How does this impact us,
the people who live on or
around these landforms?

11. Earthquakes & Tsunamis
– An earthquake is a violent shaking of the Earth’s crust
– Occur along faults, or cracks in the earth’s crust
– Happens often in the Ring of Fire, but also in other areas,
– Earthquakes beneath the ocean can produce tsunamis, or large, powerful ocean waves which can cause great destruction along the ocean coast.
– Earthquake Destruction (2:21)
– Killer Tsunamis (3:28) 2011 Japanese Tsunami Footage (5:39)
Earthquake Damage! Tsunami - November 2006!

12. Earthquake!
San Andreas Fault, CA, USA
China, 2008 - 8.0 Richter
Italy, 2009 - 6.3 Richter
Pakistan, 2005 - 7.6 Richter

13. Volcanoes
• A volcano is a mountain that erupts in an
explosion of molten rock, gases, and ash.
– Lava, which is molten rock, flows down the sides of
the mountain.
– The Ring of Fire contains more than 75% of the
world’s volcanoes.
– In spite of their destructive tendencies, volcanoes
can benefit, or be useful to, plants and animals by
making the soil richer
Volcano 101 (3:04)
Yellowstone Volcano (1:36)

14. Landforms
 Landforms are physical
features on the Earth’s
surface.
 They are continually
reshaped by physical
processes

15. Surface Landforms
 Mountain – a high,
steep elevation
 Hill – slopes upward,
but is lower and more
rounded
 Plain – a level area
 Plateau – a plain that
sits high above sea
level and usually has a
cliff on all sides

16. Ocean
Landforms
 Mountains, valleys, and volcanoes also
exist at the bottom of the ocean.
 Continental shelf – the edge of a
continent that extends several miles under
the ocean’s surface
 At the edge of the shelf, the land slopes
steeply to the ocean floor
Diving along the Eurasian Continental Shelf!

17. Ocean Landforms, cont.
 Valleys under the
ocean are called
trenches
 Lowest spots in the
earth’s crust
 Mariana Trench =
deepest trench in the
world, located in the
west Pacific
 Dive the Mariana Trench! (:47)

18. Ocean Landforms, cont.
Computer imaging of Puerto
Rico Trench, Atlantic Ocean
Deep
Sea - Exploring the Zones (5:54)

19. The Changing Earth
• Changes in the earth
affect plant and animal
life
• Erosion: the process by
which rocks and soil
slowly break apart and
are swept away
• Weathering: when air,
water, wind, or ice
slowly wear away rocks
and soil
– Bill Nye: Erosion (Cut at 6:48ish)

20. Erosion and Weather at Work

21. Waters of the Earth
Water flowing in rivers
is essential – or
necessary – for all
forms of life!
 About 70% of the
earth is water!
 Most of it is salt
water, which people
can’t drink

22. Fresh Water
 People use fresh
water to drink, cook,
and irrigate crops
 River – a path of
water that flows from
a higher elevation to
a lower elevation
 Streams, brooks, and
creeks – like rivers, only
smaller
 Lake – a large body
of water surrounded
by land

23. Salt Water
 Salt water is a major
source of seafood
and a means of
transportation
 Oceans – large bodies of
Salt Water
 Currents – continuously
moving flows of water –
circulate through oceans
affect the climates on land
 Seas – Smaller bodies
of salt water
 Ex. Red Sea

24. The Water Cycle
• Evaporation – The sun heats the ocean and water vapor
rises up into the atmosphere
• Condensation – Cooler temperatures in the atmosphere
cause the water vapor to change into droplets that form
clouds
• Precipitation -- Water droplets grow heavier and fall back
to Earth in the form of precipitation, which is rain or snow
• Runoff (or Collection) – Precipitation soaks into the
ground and runs into rivers , underground water
reservoirs, and eventually, the ocean

26. Percentage of Water on Earth:
– 96.5% Oceans
– 1.7% Ground Water
– 1.8% Surface Water
– .024% Other Water
– (Ground ice, atmospheric water vapor, marshes/wetlands,
and in lorganisms
–Of the amount of water on earth,
only 2.5% is available for human use!
• Water Cycle Rap
• Thirstin's Water Cycle
• Soccer Game
• Stuck In Your Head Song

27. Landforms:
An Amazing Variety!

28. Escarpment
DEFINITION: A long, steep, cliff-like
ridge of land or rock, commonly
formed by faulting or fracturing of
the earth's crust

29. Terrace
DEFINITION: A leveled section of a
hilly cultivated area, designed to
slow or prevent rapid run-off of
irrigation water

30. Valley
DEFINITION: The
low area between
mountains or hills

31. Gully
DEFINITION:
Similar to a valley,
only smaller

32. Archipelago
DEFINITION: A
large group or
chain of islands

33. Coral Reef
DEFINITION: a reef or underwater ridge
composed mainly of coral and other organic
matter which has hardened into limestone.

34. Cove
DEFINITION: A
round indentation
or recess with a
narrow entrance,
located in the
shoreline of a sea,
lake, or river.

35. Headland
DEFINITION: An
area of land with
water on three sides
(large headlands are
called peninsulas).

36. Lagoon
DEFINITION: An area of salt
water separated from a larger
sea by a sandbank or coral reef

37. Cave
DEFINITION: A natural
underground opening in a
cliff or rock, big enough for a
person to enter.

38. Gorge & Canyon
DEFINITION: A deep valley
with steep sides, formed
by streams carving
through plateaus. (A gorge
is a small canyon!)
Above: Royal Gorge, CO
Right: Grand Canyon

39. Waterfall
DEFINITION: A flow of water that drops over
rocks, usually from a height of several feet.

40. Big Spring, Ozarks, MO (Largest spring in the U.S.!
Spring
Right: Grand Prismatic
Spring, Yellowstone
(160 degrees F!)
DEFINITION:
A place where
groundwater flows
out of the ground.

41. Crevasse
Gorner Glacier,
Zermatt, Switzerland
Easton Glacier,
Mount Baker, WA
Exploring bottom of
crevasse in Antarctica
DEFINITION:
A crack in a
glacier or
snow field.

42. Fjord Above: Fjords on coast of Greenland
(Bottom is largest fjord in the world!)
DEFINITION: A valley
with steep sides, which
is below sea level and
filled with salt water.

43. Mountain
DEFINITION: A natural elevation of
the earth's surface rising to a summit,
steeper and higher than a hill.

44. Cinder Cone
DEFINITION: A small,
cone-shaped volcano
built of ash and cinders.

45. Oceanic Trench
DEFINITION: A long narrow steep-sided
depression in the earth's crust under the
ocean.

46. Lava Dome
DEFINITION: A mound-shaped
growth resulting from the
eruption of lava in a volcano

47. Tea Table
DEFINITION: A rock
formation that has been
eroded away in the shape
of a table

48. Limestone Pavement
DEFINITION: Exposed limestone
rock that looks like artificial
pavement with cracks in it.

49. Hoodoo
DEFINITION:
A tall, thin
spire of rock
that sticks up
from the
bottom of an
dry drainage
basin or
badland.

50. Any questions?