Geography Chapter 2 A Living Planet

Transcription

1 Geography Chapter 2 A Living Planet The Earth Inside and Out pp Bodies of Water and Land Forms pp Internal Forces Shaping the Earth pp External Forces Shaping the Earth pp

2 1. Earth the Inside and Out Earth is part of the Solar System Third rock from the Sun Solar system is a group of bodies that orbit the Sun

3 The Solar System

4 2. The Structure of the Earth About mile Circumference and 7900 mile diameter Made up of Three main parts Core center made up of Iron and Nickel Mantle Soft layers of molten rock called Magma Crust Solid rocky outer layer we live on

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6 Parts of the Core Inner Core made of highly pressurized Iron and Nickel 760 mile radius Outer Core Surrounds the Inner Core 1380 miles thick

7 Mantle Lower Mantle Surrounds the outer core 1300 miles thick Upper Mantle Made of the Asthenosphere and Lithosphere (inner layers of Crust ) 500 Miles thick Mantle composed of hot liquid magma

8 Crust Top of Lithosphere Outer layer where we live. Thin layer of rock on the outer surface of the Earth

9 On and Above the Earth Atmosphere gases that surround the Earth allow us to breath Lithosphere - Rocky part of the Earth we live on, the continents Hydrosphere Oceans / water Biosphere where we live

10 Continental Drift The theory that all the continents once formed one supercontinent and drifted apart on Magma. Called Pangaea

11 Disaster! Asteroid Hits Earth contributing the extinction of Dinosaurs and the eventual rise of mammals.

12 2. Bodies of Water and Landforms Oceans, Seas Lakes Rivers Streams Ground Water

13 Oceans, And Seas Largest bodies of Water 71% of the Earth surface Four Oceans Atlantic, Pacific, Indian, Artic

14 The Four Oceans

15 Ocean Motion Oceans are made of salt water The flow through 3 basic motions Tides Rise and fall with the Lunar Cycle Currents Act like rivers flowing through the ocean Waves Swell or ridges produced by winds

16 Tides Rise and fall with the Moon The Moons gravitational pull on the Earth cause the waters to Swell towards the Moon

17 High Tide and Low Tide

18 Ocean Currents

19 Waves

20 Waves: Storm Surge

21 Example of Storm Surge

22 Waves: Tsunami Caused By an under water disturbance Can travel thousands of miles Extremely destructive

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24 Hydrologic Cycle: The interaction between the Earth s waters and atmosphere

25 Lakes Rivers and Streams 95 % of the Earth s fresh water supply is in lakes Lake Baikal Largest in the world Great Lakes Result of Glaciers from the Ice Age Rivers and Stream move water through channels to large bodies Connect to each other forming Drainage Basins

26 Ground Water

27 Landforms Naturally formed features on the Earths surface

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29 Oceanic Landforms:

30 Continental Shelf

31 3. Internal forces shaping the Earth Continental Landforms Relief - Feature that separates one landform from another Topography Combination of surface shape and the composition of a land form

32 Plate Tectonics Internal forces shape the Earths surface Heated magma moves up to the crust and cools and then circulates downward this movement causes the crust to shift Enormous moving pieces of crust called Tectonic Plates ride on the Magma and shift from time to time

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34 Plate Movement Tectonic Plates move in four ways 1. Spreading or moving apart 2. Subduction or diving under each other 3. Collision or crashing into each other 4. Sliding or shearing past each other Three types of boundaries mark plate movement 1. Divergent spreading apart 2. Convergent colliding causing one plate to rise and other to fall 3. Transform Plates sliding past each other

35 Divergent Boundary Hot magma rises and pushes the plates apart

36 Convergent Subduction When an oceanic plate collides with a continental plate it creates a volcanic zone

37 Convergent Collision When two continental plates collide it creates a mountain range

38 Transformation Plates slide past each other causing a fault line

39 Folds and Faults When two plates meet they cause folding and cracking. The rock bends under pressure exerted by the plates When the plates crack it create a fault line

40 Earthquakes Plates grinding and slipping past each other causing the Earth to shake Thousands occur each year but most are so small you can not feel them Epicenter - the point where the earthquake begins Seismograph detects earthquakes Richter scale measures the power of an earthquake on a scale of 1-10 Famous Earthquakes 1906 San Francisco 1989 Loma Preiti

41 Famous Earthquakes 1906 San Francisco 1989 Loma Preita

42 Volcanoes Eruptions of Magma to the Earths surface

43 Pacific Ring of Fire The Fault lines and volcanoes that ring the west coast for North and South American and over to Asia and Australia

44 4. External Forces Shaping the Earth Weathering Delta Sediment Mechanical Weathering Chemical Weathering Erosion Loess Glacier Glaciation Moraine Humus

45 Weathering Refers to physical and chemical process that change the characteristic of rock on or near the Earths surface Occurs Slowly over many years or centuries Weathering causes large pieces of rock to break down to smaller and smaller pieces These are called Sediment Sediment is small pieces of weathered rock mostly mud sand or silt Two types of weathering 1. Mechanical 2. Chemical

46 Mechanical Weathering Does not change the composition of the rock only the size All sorts of things can cause mechanical Weathering Water / Ice / Frost Plants Human activities When it breaks down small enough the sediment combines with organic material to become soil

47 Chemical Weathering When rock is changed into a new substance altering the composition of the rock. Some minerals reacts with chemicals and change Iron reacts with water and rust I

48 Erosion Occurs when a weathered material is moved by the wind or water It is done either by flowing water, Wind, or glaciers

49 Water Erosion Water Erosion as water speeds up it carries the sediment from the river basin As it slows it deposits it in another location reshaping the river banks The mouth of a river forms a delta from all the deposits of sediment

50 Wind Erosion Similar to Water Erosion Transports sediment changing the landscape Dust storms The wind deposits the loess or sediment that is carried in a dust storm

51 Glacial Erosion Glacier large long sheet of Ice that moves because of gravity Pushes or carried sediment Can carve out landscapes over time Moraine is the rocks left behind a glacier

52 Building Soil Humus is the combination of organic material and sediment Organic matter helps support plant growth Five Factors contribute to creating soil 1. Parent Material - the chemical composition of the rock and organic material 2. Relief Steep slopes like mountains erode easily 3. Organism plants and small animals that deposit material 4. Climate how hot, cold wet or dry an area is 5. Time about 2.5 cubic centimeters a century