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

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

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 - https://www.youtube.com/watch?v=VMxjzWHbyFM Stop at 2:21- do Geosphere and Biosphere notes, then do Investigation (the rest of the video) Copyright © Houghton Mifflin Harcourt Publishing Company 3

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. Copyright © Houghton Mifflin Harcourt Publishing Company 4

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. Copyright © Houghton Mifflin Harcourt Publishing Company 5

Unit 1 Lesson 1 Earth’s Spheres What is the geosphere? Describe the characteristics of the layers of Earth. Copyright © Houghton Mifflin Harcourt Publishing Company 6

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 Copyright © Houghton Mifflin Harcourt Publishing Company 7

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 - https://www.youtube.com/watch?v=UXh_7wbnS3A Stop at 2:25, then take notes, then do Investigation (rest of video) Copyright © Houghton Mifflin Harcourt Publishing Company 8

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 Copyright © Houghton Mifflin Harcourt Publishing Company 9

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 500-600 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 Copyright © Houghton Mifflin Harcourt Publishing Company 10

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). Copyright © Houghton Mifflin Harcourt Publishing Company 11

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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 https://www.youtube.com/watch?v=BnpF0ndXk-8 – Big Idea 3 – Earth is a Complex system of earth, water, air and life Copyright © Houghton Mifflin Harcourt Publishing Company 21

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? Copyright © Houghton Mifflin Harcourt Publishing Company 22

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 Copyright © Houghton Mifflin Harcourt Publishing Company 23

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. Copyright © Houghton Mifflin Harcourt Publishing Company 24

Lesson 2 - Weathering What’s weathering? Breakdown of rock material 2 types Physical (know 6 types) Chemical (know 4 types)

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

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

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

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

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

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

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) 1908 1969

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

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