1. 8th Grade – The Dynamic Earth
Unit 1 – Earth’s Surface

2. Unit 1 – Earth’s Surface Lesson 1 – Earth’s Spheres

3. Unit 1 Lesson 1 Earth’s Spheres
The earth as a system
System = a group of related objects or parts that work together to form a whole.
Earth system = all of the matter, energy, and processes within Earth’s boundary.
Earth is a complex system made of living and nonliving things, and matter and energy continuously cycle through the smaller systems.
CCK - Intro to Geosphere and Biosphere -
Stop at 2:21- do Geosphere and Biosphere notes, then do Investigation (the rest of the video)
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4. Geosphere Mostly solid, rocky part of Earth.
Unit 1 Lesson 1 Earth’s Spheres
Geosphere
Mostly solid, rocky part of Earth.
extends from the center of Earth to the surface of Earth.
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5. Geosphere Crust - thin, outermost layer of the geosphere
Unit 1 Lesson 1 Earth’s Spheres
Geosphere
Crust - thin, outermost layer of the geosphere
mostly silicate minerals.
Oceanic crust - 5 to 10 km thick.
Continental crust - 35 to 70 km thick.
Mantle - layer that lies below the crust.
about 2,900 km thick.
made of very slow-flowing, solid rock, consisting of silicate minerals that are denser than the silicates in the crust.
Core – central part
radius of about 3,500 km.
made of iron and nickel
very dense.
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6. Unit 1 Lesson 1 Earth’s Spheres
What is the geosphere?
Describe the characteristics of the layers of Earth.
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7. Unit 1 Lesson 1 Earth’s Spheres
Biosphere
Made up of living things and the areas of Earth where they are found.
Usually need oxygen or carbon dioxide to carry out life processes.
Also need liquid water, moderate temperatures, and a stable source of energy
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8. Cryosphere Made up of all of the frozen water on Earth.
Unit 1 Lesson 1 Earth’s Spheres
Cryosphere
Made up of all of the frozen water on Earth.
Snow, ice, sea ice, glaciers, ice shelves, icebergs, and permafrost
Changes in the cryosphere can play an important role in Earth’s climate and
species’ survival.
Intro to Hydrosphere and Atmosphere -
Stop at 2:25, then take notes, then do Investigation (rest of video)
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9. Hydrosphere Part of Earth that is liquid water.
Unit 1 Lesson 1 Earth’s Spheres
Hydrosphere
Part of Earth that is liquid water.
Oceans, lakes, rivers, marshes, groundwater, rain, & water droplets in clouds.
Constantly moving
Within oceans – currents
Between spheres
In & out of living things
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10. Unit 1 Lesson 1 Earth’s Spheres
Atmosphere read pg. 10
Mixture of mostly invisible gases that surround Earth.
Most gasses are 8-50 km above earth
BUT atmosphere goes km up
About 78% nitrogen, 21% oxygen, and 1% other gases like argon, carbon dioxide, and water vapor.
contains the air we breathe
traps some energy from the sun -helps keep Earth warm enough for living things to survive and multiply
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11. Atmosphere (continued)
Unit 1 Lesson 1 Earth’s Spheres
Atmosphere (continued)
Absorbs and reflects harmful ultraviolet (UV) rays from the sun, protecting Earth
Causes space debris to burn up before hitting Earth (meteors).
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18. https://aileenshu. files. wordpress. com/2013/10/272068_l_srgb_s_gl

21. Interaction of Earth’s Spheres
Unit 1 Lesson 1 Earth’s Spheres
Interaction of Earth’s Spheres
Matter and Energy move through spheres
read pg. 13
Matter CYCLES through the spheres –
WATER: Atmosphere and hydrosphere interact when water evaporates
NITROGEN: Bacteria in biosphere takes Nitrogen from atmosphere and releases it into the soil (geosphere). Plants then use it to grow (biosphere)
Carbon: carbon dioxide is exhaled by animals, used by plants in photosynthesis; carbon composes the tissues of almost all living things
Energy FLOWS through the spheres –
Plants use solar energy to make food. Energy goes into animals that eat it, released as heat or activity
Solar energy also heats air, makes wind, creates ocean currents
– Big Idea 3 – Earth is a Complex system of earth, water, air and life
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22. How do Earth’s spheres interact?
Unit 1 Lesson 1 Earth’s Spheres
How do Earth’s spheres interact?
How many parts of the Earth system can you identify in this image? How do they interact?
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23. Mostly from THE SUN! Earth’s energy
Unit 1 Lesson 1 Earth’s Spheres
Earth’s energy
Mostly from THE SUN!
tiny fraction from ocean tides and geothermal sources (lava and magma)
Energy not created or destroyed
Addition in one sphere balanced by
subtraction in another
Energy budget – movement of energy through earth’s system
read pgs. 14 & 15
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24. What is the source of Earth’s energy?
Unit 1 Lesson 1 Earth’s Spheres
What is the source of Earth’s energy?
Trace the flow of energy through Earth’s system.
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25. Lesson 2 - Weathering What’s weathering? Breakdown of rock material
2 types
Physical (know 6 types)
Chemical
(know 4 types)

26. Physical Weathering 1. Temperature changes
Hot / cold causes rock to expand & contract
More dramatic in dry regions (why?)
Ice/frost wedging
(do p. 21)

27. 2. Pressure Changes Rocks formed under pressure get exposed to surface
Material above rock is removed – pressure decreases – rock expands
Exfoliation – outer layers of rock peel away because of pressure changes
Picture p. 22

28. 3. Plant and Animal Action
Burrows dug by …
Prairie dogs, ants, ground squirrels, earthworms
Move soil & expose rock t surface

29. Roots start out small, as they grow put more pressure on rocks

30. 4. Wind
5. Water
6. Gravity
Abrasion = breaking down / wearing away of rock material by OTHER ROCKS
Can also happen by glaciers
Picture p. 23

31. Chemical Weathering -Breakdown of rocks by chemical means
-Changes composition & appearance
Oxidation
-Oxygen in air
or water causes
chemical reactions
color change - ex: iron + O2 = rust

32. 2. Acid Precipitation
-Gasses in air (like CO2) combine with water to make acid
- Acid rain (or snow, or sleet) breaks down minerals faster than water alone
Many statues made of limestone – CaCo3 – same mineral as egg shell
Put egg in vinegar, watch shell dissolve (takes an hour)

33. 3. Acid in groundwater -can create caves – start from small cracks
-minerals dissolved in groundwater get deposited elsewhere and can create formations
Do digital lesson slide 6 – formation of caves

34. 4. Acids produced by living things
-lichens and mosses grow on rocks & trees
produce weak acid
-like with groundwater, acids start in tiny spaces and get bigger over time
Do Digital Lesson slide 7 – matching game