Chapter 2 Physical Geography: A Living Planet

1
Chapter 2Physical Geography A Living Planet
2
CONTINENTAL DRIFT THEORY

• Originally suggested by Francis Bacon in 1620
• Presented theory in 1912 by Alfred Wegner of
  Germany
• Theory states that all continents were once a
  super continent that divided and slowly drifted
  apart

3
Where are we?

• 93,000,000 miles from the Sun
• 3rd Planet in from the Sun
• 24,900 miles in circumference and 7900 miles in
  diameter
• Only planet in Milky Way solar system that can
  sustain human life

4
THE MILKY WAY

• Our Solar system consist of the sun
• 8 planets
• 1 dwarf planet (Pluto)
• Other celestial bodies that orbit the sun
• Comets gt spheres covered with ice and dust that
  leave trails of vapor as they race through space
• Asteroids gt large chunks of rocky material found
  in space
• By size Pluto (dwarf), Mercury, Mars, Venus,
  Earth, Neptune, Uranus, Saturn, Jupiter

5
Section 1 The Earth Inside and Out

• 1. The earth is the only living planet
• Continents
• landmasses above water on earth

6

• 2. The earth consists of
• plates
• that float

7

• 3. The theory of continental drift explains the
  formation of continents

8
Inside the Earth

• Core
• center of the earth (inner core- liquid iron
  and nickel outer core solid iron and nickel)
• Mantle
• several layers surrounding the core
• Crust
• thin layer of rock at the earths surface

9
Biosphere

• The part of the earth where plants and animals
  live (atmosphere, lithosphere and hydrosphere)

10
On and Above the Earth

• Atmosphere
• layer of gases surrounding the earth (contains
  oxygen, protects the earth from radiation and
  space debris, and provides a medium for weather
  and climate

11
Lithosphere

• Solid rock portion of the earth (includes crust
  and uppermost mantle, ocean floor, etc.)

12
Hydrosphere

• Made up of water elements of the earth (oceans,
  seas, rivers, lakes and water in the atmosphere)

13
Section 2 Bodies of Water and Landforms

• Human Perspective
• The earth is unlike any other observable planet
  in our solar system. It is a living planet.
• Where there is water there is LIFE.

14
Section 2 Bodies of Water and Landforms
The ocean is interconnected and covers over 70
of the earth. Divided into 4 main parts.
Pacific (largest), Atlantic, Arctic and Indian
15
Ocean Movements

• Currents- like rivers flowing through the ocean
• Waves- swells produced by winds
• Tides - regular rises and falls of the ocean
  created by the gravitational pull of the moon or
  the sun

16
MOTION OF THE OCEAN

• The ocean distributes heat.
• Winds blow over the ocean and are either heated
  or cooled by the water, moderating the
  temperature of the air over the land.

17
Hydrologic (water) Cycle

• The water on earth is continuously circulated
  between the atmosphere, the oceans, and the earth

18
LAKES, RIVERS, STREAMS

• Lakes hold more than 95 of all fresh water on
  earth.
• Rivers and streams
• move water to or from
• larger bodies of water.

19
LAKES, RIVERS, STREAMS

• Saltwater lakes are created when creeks rivers
  carry salts
• into a lake, and there is no outlet to carry the
  salt away.
• Largest Caspian Sea (West Asia)

20

• Drainage Basin -
• Area drained by a major river and its tributaries

21
Ground Water water held in the pores of
rocks Water Table the rim level at which rocks
are saturated
22
Oceanic Landforms (topography)

• The ocean floor and the continents have a
  continental shelf and slope
• The ocean floor is similar to the land above
  water.

23
continental shelf
24
Continental Shelf

• Earths surface from the edge of a continent to
  the deep part of the ocean

25
Continental Landforms

• Naturally formed features on the surface of the
  earth are landforms

26
Topography Relief

• Relief refers to the difference in elevation of a
  landform from lowest to highest point
• Mountains, hills, plains, canyons
• The combination of the surface shape and
  composition of the landforms and their
  distribution in a region gt topography
• Topographic Maps show the landforms with their
  vertical dimensions and their relationship to
  other landforms.

27
Section 3 Internal Forces Shaping the Earth

• The earths crust consists of number of tectonic
  plates
• tectonic plates - enormous moving pieces of the
  earths lithosphere
• Spreading subduction collision sliding past
  each other in a shearing motion

28

• Movement
• of the plates
• produces
• earthquakes
• and volcanoes
• Fault fracture in the earths crust where
  plates move past each other

29
Types of boundary movements

• Divergent plates move apart, spreading
  horizontally (i.e. Saudi Arabia Egypt making
  Red sea wider)

30
Types of boundary movements

• Convergent Plates collide, causing either one
  plate to dive under the other or the edges of
  both plates to crumple (i.e. South Asia forming
  the Himalayas)

31
Types of boundary movements

• Transform plates slide past each other (i.e.
  San Andreas Fault in California)

32
Volcanoes crack in the earths surface where
magma and gases pour outBenefits gt fertile soil
energy
Lava magma that has reached the earths surface
33

• Earthquake Violent movement of the earth as the
  plates grind or slip past each other at a fault
• 95 around Pacific Rim (Ring of Fire)
• Along plate boundaries
• Seismograph
• measures the size of the waves created by and
  earthquake
• Largest Earthquake measuredgt Kermadec Island, 8.9

34
Epicenter

• Point directly above the focus of an earthquake
  on the earths surface
• Richter Scale
• uses information collected by seismographs to
  determine the strength of an earthquake

35
DAMAGE

• Landslides
• Fires
• Collapsed Buildings
• Tsunami (speeds up to 450 mph and waves 100 feet
  tall)

36
Tsunami

• A giant wave in the ocean caused by an
  underground earthquake

37
The Ring of Fire

• The most active volcano and earthquake zone on
  earth

38
(No Transcript)
39
Hot Spots

• Volcanoes that are far from the margins of the
  tectonic plates are located on Hot Spots.
• Hot springs geysers are other features that
  indicate areas where the crust is thin.

40
External Forces Shaping the Earth

• Human Perspective
• In Egypt, a seasonal dry wind is called Khamsin
  (50) for the number of days the season occurs.
  These wind-driven sandstorms cause serious
  problem for the people of the region.

41
External Forces Shaping the Earth

• Weathering and erosion alter the surface of the
  earth
• Weathering physical and chemical processes that
  change the characteristics of rock on or near the
  earths surface

42

• Sediment Small pieces of rock created by
  weathering (mud, sand or silt)
• Mechanical Weathering
• processes that break rock into smaller pieces
  (doesnt change the composition of rock, but the
  size)
• Example road construction
• 4 causes gt human activity,
• plants, frost, ice crystal in
• cracks of rocks

43

• Chemical Weathering
• occurs when rock is changed into a new substance
  as a result of interaction between elements in
  the air or water and minerals
• (example iron rusting)

44
Erosion

• Occurs when weathered material is moved by the
  action of wind, water, ice and gravity

45
Water Erosion

• The motion picks up loose material and moves it
  downstream
• Delta
• sediment is deposited in a fan-like landform when
  a river enters an ocean

46
Wind erosion

• Wind speeds have to reach 11 mph before fine
  sediments can be moved.
• Depending on the types of wind, different types
  of landforms can be formed
• Loess, sand dunes, rock structures.

47
wind erosion
Loess windblown silt and clay sediment that
produces very fertile soil
48
Glacial Erosion

• Glacier - a large, long-lasting mass of ice that
  moves because of gravity
• (Form in mountainous regions)
• Glaciation
• changing of landforms by slowly moving glaciers
• Moraine
• rocks left behind from a glacier that form a
  ridge or hill

49
BUILDING SOIL

• HUMUS -
• Organic material in the soil.
• Esker gt snakelike ridge
• Created by melted ice

50

• Kettle gt depression in the ground created by
  blocks of trapped ice in the sediment that melts.
  They can fill with water to form lakes.

51

• Weathering and erosion help form soil. Soil
  consist of a loose mixture of weathered rock,
  organic matter, air, and water that supports
  plant growth
• Factors that determine
• soil fertility
• Parent Material
• Relief
• Organisms
• Climate
• Time

52

• The variety and the climates in which they are
  found determine the types of vegetation that
  can grow in a location. Agricultural activities,
  such as farming, ranching, and herding, depend on
  this complex relationship.