The physical environment chapter discusses the components that make up Earth's physical environment: land, air, water, and the living environment. It describes key landforms like mountains and rivers, as well as geological processes that create and modify landforms such as plate tectonics, folding, volcanism, and erosion. Weathering and erosion by forces such as water, wind, and plant growth gradually break rocks into sediment and transport material from one place to another over long periods of time, shaping the surface of the planet. Human activities and settlement patterns are also influenced by landforms and geological characteristics of different regions.

1. PHYSICAL ENVIRONMENT
CHAPTER 7

2. THE PHYSICAL ENVIRONMENT
• Made up of various components or things,
including:
– Land-landforms, rocks
– Air-weather, climate
– Water- rivers, lakes, oceans
– Living Environment – wildlife, natural vegetation

3. Landforms & Rocks
• Created and changed by
processes beneath and
on the Earth’s surface.
• i.e. of Landforms:
mountains, volcanoes
• i.e. of rocks limestone,
granite

4. Rivers Lakes and Oceans
• Covers 75% of earth’s
surface
• Rivers-streams of
water that flow from
high ground to low
ground

5. Weather & Climate
• Atmosphere-gaseous
environment surrounding
earth.
• Weather- the condition of
the atmosphere over a
short period of time
• Climate- weather conditions
over a long period of time.
• Elements of weather:
temperature, rainfall, and
wind.

6. Natural Vegetation
• Plants not planted by people and that grow naturally

7. Interrelationships between the
components
• All these are connected to each other
• i.e. Rain affects the plants that grow
• Help us to understand how these components
affect our lives.

8. Prompt
•Do you think it’s
important to appreciate
the world we live in?
Why or why not?

9. WORKSHEET

10. WKBOOK PG. 45

11. Landforms on the Earth

12. Earth’s Surface
• Is not flat and is shaped
in many different sizes
and shapes.
• It’s also NOT one solid
mass of rock

13. Earth’s Surface
• Most of the physical
features on Earth’s
surface are landforms
• Landforms make the
shape of the land
• Landforms can be all
different shapes and
sizes

14. Earth’s Surface
• Highest point on land -
Mt. Everest in Nepal
(8850 meters )
• Lowest point on land-
Dead Sea in Israel (400
meters deep)

15. Types of Landforms
Mountain
• Area of high ground usually
more than 600m.
• Steep slopes & narrow top
or peak
• When formed close
together they form a
mountain range

16. Types of Landforms
Hill
• Area of high ground
• usually less than 600 m
• Usually rounded in shape
with gentle slopes

17. Types of Landforms
Valley
• Low area of land between
hills or mountains

18. Types of Landforms
Plain
• Broad, flat, and low area on
earth’s surface

19. Types of Landforms
Plateau
• Raised area of land with a
fairly flat, broad top and
steep slopes

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21. Worksheet

22. Inside Earth
• Earth is made of 3 basic
layers
• Core
• Mantle
• Crust

23. The Core
• At the center of the Earth
• Temperatures can be as
high as 5000 degrees
Celsius
• Inner core is solid
• Know why?
• Pressure & weight
exerted on the core by
the outer layers of the
Earth

24. The Mantle
• 2900km thick!
• 80% of earth’s volume
• More than 2000
degrees Celsius
• Upper part is semi-
molten or semi-liquid
state

25. The Crust
• Outermost layer of earth
• Varies between 6-70km thick
• Made up of many plates
• The plates float on the semi-molten mantel
• The pieces are different sizes & they fit together like a
jigsaw puzzle

26. Internal Forces that Create Landforms
• Crustal movement-the
moving plates of earth’s
crust
• Plates move very slowly
1-5 cm/year
• Plates may slide, push, or
pull apart from each
other
• Mountains & volcanoes
are formed from the
processes within Earth’s
surface

27. Plate Types

28. Folding
• When two plates collide
with each other layers
of rock buckle and form
folds
• Folding can be barely
noticeable or so large
mountains form
• These type of
mountains are called
fold mountains

29. Fold Mountains
• Himalays in Nepal
• Formed 40-50 million
years ago
• Still growing today
• Why?
• Also found in Andes,
Alps, and Appalachian
mountains

31. Vulcanicity
• The process through
which magma and
other materials reach
Earth’s surface
• The hot temperatures
causes earth’s mantle to
melt
• Magma reaches earth’s
surface through cracks
in the crust

32. Vulcanicity
• Outpouring of lava is
called an eruption
• The build up of pressure
caused by gases leads
to a volcanic eruption
• Magma may flow out
quietly or by violent
eruptions

33. Vulcanicity
• At Earth’s surface lava
hardens as the
temperature is cooler
• The build up of lava
through a single hole
can create a cone-
shaped volcano

34. Volcanoes-Basic Structure
• Consists of a vent, pipe,
crater and cone
• Vent-opening in earth’s
surface
• Pipe-channel allowing
magma to rise to the top
• -crater-bowl-shaped
opening where ash & lava
are released
• Cone-built up by ash and
lava released from
multiple eruptions

35. Volcanoes Around the World
• Form around plate
boundaries
• A large number are
around the Pacific
Ocean in an area known
as the Pacific Ring of
Fire

36. WHAT ARE THE 3
DIFFERENT TYPES OF
VOLCANOES?

37. Types of Volcanoes
Active
• Erupts from time to time
and likely to erupt again
• i.e. Krakatau - Indonesia
Dormant
• “sleeping volcano”
• Presently inactive but may
erupt again
• i.e. Mt. Fuji in Japan

38. Types of Volcanoes
Extinct
• Scientists consider it
unlikely to erupt again.
• i.e. Mt. Kilimanjaro in
Tanzania
• We can never be too sure if
a volcano is truly extinct

39. Plateaux
• Formed when a large
amount of magma
escapes from a long
crack and spreads over
a large area
• The lava solidifies and
after numerous
eruptions a plateau
forms
• i.e. Columbia Plateau

40. HOMEWORK: READ 88-91
TEXTBOOK

41. WORKBOOK PAGES 48-50 & 53-54

42. Reading Check
• What are 2 risks of living near a volcano?
• What are 2 benefits to living near a volcano?
• What is another name for Mount Merapi?
• What city is Mt Merapi located in?
• What are at least 2 things the local government
has done in case of an emergency from Mt.
Merapi?

43. External Forces that Modify Landforms
Weathering
• Process by which rocks are
progressively broken down
into fragments
• Can be caused:
– Changes in temperature
– Action of water
– Action of plants

44. Large Changes in Temperature- Desert
• Heat causes the surface
of the rock to expand
during the day and at
night
• Inside of rock remains
cool
• At night the air cools,
temperatures drop & the
surface contracts
• This weakens the rocks
surface layer
• If water is present the
rock will break off in
layers

45. Action of Water
• Rainwater combines
with carbon dioxide to
form carbonic acid
• Dissolves rocks like
limestone
• Over time can form
landforms like caves

46. Action of Freezing Water
• On high mountains
melting snow or rain
may enter cracks
• At night the water
freezes and expands
causing rocks to crack
• During the day the ice
melts and the process
starts over causing
rocks to eventually
break apart

47. Plant Growth
• Wind may drop seeds
into cracks of rocks
• Seeds grow into plants
and forces crack to
widen
• Over time the entire
rock may fall apart

48. Erosion
• Process of wearing
down surface materials
and moving them from
one place to another
• Caused mainly by:
– Running water
– Waves
– wind

49. Action of Running Water
• Water in streams and
rivers carry a lot of
sediments (small particles
like sand, mud, silt)
• The sediments act like
sand paper as it flows
over rocks and scrapes
and wears away at them
• Over time can form
canyons

50. Action of Waves
• Powerful agents of
erosion
• The constant breaking
of waves against the
shore together with the
grinding action of sand
and stones produces
sandy beaches, caves,
and cliffs

51. Action of Wind
• Wind erosion is common
in dry areas with few
plants to hold the soil or
other loose materials in
place
• In deserts strong winds
can carry large amounts
of sand and wear away
rock surfaces
• Since sand is heavy wind
erosion takes place
mainly at the base of
rocks

52. HTTP://WWW.YOUTUBE.COM/WAT
CH?V=EXS9GFXGIB0
Erosion & Weathering

53. How Landforms Affect People
• Where they choose to
live
• The way people live
• And the type of activity
they engage in

54. Location of Homes
• It’s hard to build on
steep slopes
• People prefer plains and
valleys
• i.e. Kinta Valley in Perak
Malaysia- people built
their homes on the flat
valley floor
• Tin ores also attracted
people to the site

55. Location of Homes
• Indonesia- people still
choose to live near
volcanoes despite risk
b/c of fertile soil

56. Human Activities
• People earn living
through farming if they
live near volcanoes
• People have adapted by
cutting terraces into the
slopes
• Plains allow people to
build homes and other
buildings

57. Human Activities
• Recreational activities
like skiing, trekking, and
mountain climbing take
place on mountains and
hills
• Tourists attractions
– Ayers Rock in Australia

58. TEXTBOOK PAGE 98

59. EROSION AND WEATHERING ARE
USUALLY CAUSED BY NATURAL
PROCESSES, BUT HUMAN ACTIVITIES
ALSO HAVE A MAJOR IMPACT ON THE
AMOUNT OF EROSION THAT OCCURS.
CAN YOU THINK OF WAYS THAT PEOPLE
MOVE OR ALTER LAND, AND WHY
PEOPLE MIGHT WANT TO DO THIS?
What do you think?

60. HTTP://SCIENCENETLINKS.COM/INT
ERACTIVES/SHAPEITUP.HTML

61. Pop Quiz
• What are the 3 types of volcanoes?
• What are the 3 types of plate boundaries?
• In your own words explain folding.
• In your own words explain vulcanicity.