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4th Grade Earth Systems 2015 11 10 www.njctl.org 2
Earth Systems Click on the topic to go to that section Earth's Systems Mechanical Weathering Chemical Weathering Erosion Biogeology 3
Earth's Systems Return to Table of Contents 4
Earth's Systems Earth has many parts that work together to make it the way that it is. Can you think of some parts of the Earth that work together? 5
Earth's Systems Earth has four systems that are continually working together. Do you know the names of any of the systems represented in these pictures? 6
Earth's Systems The four systems that work together are: the atmosphere the biosphere the geosphere the hydrosphere 7
Earth's Systems Atmosphere The atmosphere is a layer of gases that surrounds Earth. The atmosphere includes the air around us. Layers of gases within the atmosphere interact with each other. We can feel when these layers interact through a cool breeze or the thick air of a hot and humid day. 8
Earth's Systems Biosphere The biosphere is where life is found. The biosphere includes: animals, plants, and all living organisms. Answer What do you think the prefix "Bio" means? 9
Earth's Systems: Geosphere The geosphere is the solid, rock part of Earth. The geosphere includes: the interior of Earth (the mantle and core), the crust, rocks, and all landforms that make up Earth. Answer Can you guess what the prefix "Geo" means? 10
Earth's Systems Hydrosphere The hydrosphere is all of the water on Earth. The hydrosphere includes: oceans, lakes, rivers, streams, water in the air, snow, rain, and sleet. Answer "Hydro" means. 11
Earth's Systems How is this fish tank like Earth's four systems? Right now, write a few complete sentences to answer this question. 12
Earth's Systems All of Earth's systems work together and interact with each other. Where do we see Earth's four systems here? (click the boxes to reveal the answers) atmosphere sky biosphere trees geosphere cliff hydrosphere lake 13
Earth's Systems What systems do we see here? atmosphere sky biosphere trees geosphere rocks river hydrosphere 14
Earth's Systems What systems can we see here? biosphere sea turtle hydrosphere ocean 15
1 Earth has four systems that work together. True False Answer 16
2 The includes water in, on, and surrounding the Earth. A atmosphere B biosphere C geosphere Answer D hydrosphere 17
3 The solid, rock part of Earth is the. A hydrosphere B atmosphere C geosphere Answer D biosphere 18
4 The system that includes all life on Earth is the. A biosphere B geosphere C hydrosphere Answer D atmosphere 19
5 The is the layer of gases that surrounds Earth. A geosphere B hydrosphere C atmosphere Answer D biosphere 20
6 Which of Earth's systems includes the crust? A hydrosphere B biosphere C atmosphere Answer D geosphere 21
7 These are part of which system? A atmosphere B hydrosphere C biosphere D geosphere (snow) Answer (rain) 22
8 Is this squirrel part of the geosphere? Yes No Answer 23
Mechanical Weathering Return to Table of Contents 24
Mechanical Weathering We know that sometimes Earth's systems work together to build up or create new rocks or crust particularly the geosphere as tectonic plates interact. the geosphere building up rocks in the form of a mountain range But Earth's systems also work together to break down Earth's crust. 25
Mechanical Weathering Weathering is the breaking down or dissolving of rocks, minerals, and sediments on Earth's surface. Weathering breaks down the land around us and shapes what we see on the surface. 26
Mechanical Weathering Mechanical weathering is one type of weathering. Mechanical weathering is when physical processes break down rock. For example, all of these small rocks were once part of the ledge above, but now physical forces have broken them off. 27
Mechanical Weathering An auto mechanic can help us remember what mechanical weathering does. What does a mechanic do? (click the box to find the answer) A mechanic uses tools to break a car into smaller pieces. You may know other things a mechanic does, but remembering that a mechanic does this can help us remember what mechanical weathering is. 28
Mechanical Weathering Like a mechanic who uses tools to take apart cars, mechanical weathering is Earth's way of using different physical tools to break apart features on its surface. An auto mechanic may use these tools: Mechanical weathering uses a different set of tools. Can you guess what they are? 29
Mechanical Weathering The tools of mechanical weathering are: (click boxes for answers) water ice heat plants wind glaciers All of these work to break down the rocks of Earth's crust. 30
Mechanical Weathering Some tools of mechanical weathering are: (click boxes for answers) plants wind glaciers All of these work to break down the rocks of Earth's crust. 31
Mechanical Weathering Some more tools of mechanical weathering are: (click boxes for answers) water ice the Sun All of these work to break down the rocks of Earth's crust. 32
Mechanical Weathering Water Water is a strong force that breaks down rocks. Here, waves have smashed against these rocks so many times that the rocks are now smoothed out and worn away. 33
Mechanical Weathering Ice When water freezes, it expands. When water gets into rocks and freezes, it expands inside the rock and causes the rock to crack. Click to watch a video demonstrating how ice can powerfully break apart rocks. Can you explain in your own words what happened in this video? 34
Mechanical Weathering Heat and Temperature Change Temperature, the change between hot and cold, is another force of mechanical weathering. This rock, which has many layers, is broken like a puzzle after many seasons of heating and freezing. 35
Mechanical Weathering Plants Plants also can break apart rocks. Here, this tree has grown into the rock and caused it to crack. The roots of plants often break apart rocks. 36
Mechanical Weathering Wind Although wind can be hard to see with our eyes, its effects on rocks are not. softer rock layers very weathered by the wind harder rock layers less weathered by the wind Here we can see how wind has weathered the softer layers this rock more than the harder layers. 37
Mechanical Weathering Glaciers Glaciers are giant masses of ice, often a mile high. They are extremely heavy, and can crush rock beneath them. The ice and water from glaciers can also weather rocks by freezing in cracks. This rock shows marks from a glacier scraping its surface. 38
Mechanical Weathering Mechanical weathering is constantly at work. Which Earth system does mechanical weathering break down? The geosphere is broken down by weathering. Do you notice which Earth systems work to break down rocks? 39
9 Mechanical weathering changes the size and shape of rocks. True False Answer 40
10 What does an auto mechanic do that is similar to what mechanical weathering does? A fixes things that are broken B uses tools to put things together C uses tools to break things apart Answer D figures out a problem and how to fix it 41
11 Which of the following is not a form of mechanical weathering? A plants B gravity C temperature change Answer D glaciers 42
12 Does rock that is hard weather faster than rock that is soft? Yes No Answer 43
LAB: Ice Breaks Rocks How does ice break rocks apart? In this lab, we will create models of how ice breaks apart rocks. 44
LAB: Water Weathers How does water mechanically weather rocks? In this lab, we will create models of how water weathers rocks. Get your arms ready to do some shaking! 45
Chemical Weathering Return to Table of Contents 46
Chemical Weathering Chemical weathering is the second type of weathering. Chemical weathering is when chemicals change the materials that make up a rock. Chemical weathering does not just break down rocks like mechanical weathering does, but actually changes what the rocks are made of. 47
Chemical Weathering For example, you can see where this rock has been chemically weathered. It has changed from being a smooth brown rock to a rough yellow one. 48
Chemical Weathering A chemist can help us remember what chemical weathering does. What does a chemist do? (click on the box to find the answer) A chemist uses chemicals to change one material into another. You may know other things a chemist does, but remembering that a chemist does this can help us remember what mechanical weathering is. 49
Mechanical Weathering Water and heat are the two largest means through which chemical weathering occurs. 50
Mechanical Weathering Water Rain is not pure water. It contains acids that, over time, can dissolve rocks. Have you ever seen a statue like these, worn down and smooth? Over time statues made of rock get this way because of acid rain. The acid rain dissolves the rock the statue is made of. 51
Mechanical Weathering Water Acid rain has dissolved some of the rock in these statues. From looking at the pictures closely, can you tell what it means to dissolve a rock? 52
Mechanical Weathering Water Acid rain can also cause rocks to rust. Here, acid rain water flowed into this rock through the crack towards the front of the slab. The darker portion is iron rust. We can also see rust on this rock. 53
Mechanical Weathering Water On top of acid rain, other bodies of water can also carry acids and chemicals that have the power to change the rocks around them. The lake at the bottom of these falls is green because of the dissolved minerals and chemicals it has picked up from the river. 54
Mechanical Weathering Water Caves (left) and karsts (right) are also created from water that contains acid wearing away at rocks. 55
Mechanical Weathering Heat Heat, too, can change the material a rock is made of. Exposure to hot air over time can cause changes like this. Chemical reactions caused by heat and water break down the bonds holding the rocks together, causing them to fall apart, forming smaller and smaller pieces. 56
13 Chemical weathering is the process of. A breaking down rocks into smaller pieces B changing the size of pieces a rock is made of C mixing chemicals Answer D changing the material a rock is made of 57
14 Rainfall can make rocks dissolve. True False Answer 58
15 Which of the following is NOT an example of chemical weathering? A A rock freezes and breaks. B A rock turns red with rust. C A rock is dissolved and washed away. Answer D A rock changes color and composition when exposed to air. 59
16 When a large rock falls off a cliff and breaks into many small pieces, this is an example of weathering. A mechanical B chemical Answer 60
Weathering Review Discuss in small groups: How do you think mechanical and chemical weathering relate to Earth's four systems? Which of the four systems are involved in weathering? Which of the four systems get weathered? Are any of the systems not very involved in weathering? 61
ACTIVITY: Modeling Chemical Weathering How does chemical weathering work? We will look at how chemical weathering works through two activities using chalk and old pennies. 62
LAB: Chemical Weathering How does chemical weathering affect different types of rocks? This lab will take multiple days and involves conducting MOHS HARDNESS TEST of a number of rock samples. Get ready! 63
Erosion Return to Table of Contents 64
Weathering and Erosion Weathering causes rocks to break down into smaller pieces. Erosion is the movement of these small pieces to different locations. There are several ways erosion occurs. 65
Erosion by Gravity Mechanical weathering broke these rocks into small pieces, but gravity caused them to move to a new location. This is erosion. 66
Erosion by Wind This rock experienced mechanical and chemical weathering. Then the wind carried the small pieces of rock, sand and debris away. 67
Erosion by Rain After weathering has broken up materials, rain can wash it away. 68
Erosion by Rivers As rivers flow, they move sediment and other materials that have been broken down by weathering. 69
Erosion by Oceans Oceans carry broken rock, sediment, and sand to other locations. 70
Erosion by Glaciers Glaciers can move pieces of rock and sediment to different locations. 71
Erosion Sometimes the same factors can cause both weathering and erosion. What is causing weathering and erosion in this picture? Click the box to check your answer. The glaciers' pressure breaks down the rock beneath it (weathering). The glaciers' movement carries the rock away (erosion). 72
Erosion What is causing weathering and erosion in this picture? The ocean waves break apart the land (weathering). The water washes the small pieces away (erosion). 73
Erosion This is a picture was taken during aftermath of Hurricane Katrina in 2005. Discuss how you think a hurricane can cause weathering and erosion. 74
17 Erosion is the breaking down of rocks into smaller pieces. True False Answer 75
18 When a glacier crushes the rock beneath it, this is an example of. A mechanical weathering B chemical weathering C erosion Answer 76
19 When a glacier moves small rocks to a new location, this is an example of. A mechanical weathering B chemical weathering C erosion Answer 77
20 Can rocks or sediments that are washed away or moved by erosion change their form? Yes No Answer 78
21 Which of Earth's four systems are involved in weathering and erosion? A atmosphere B biosphere C geosphere Answer D hydrosphere 79
22 Discuss at your table how all four of Earth's systems are involved in weathering and erosion. the atmosphere the biosphere the geosphere the hydrosphere 80
LAB: Erosion How are new landforms created through erosion and deposition? During this lab, we will create models of landforms and then erode them with water. Make sure you are a good observer throughout the lab. 81
LAB: Weathering & Erosion How are weathering and erosion related? Using skittles, you will create a model of weathering and erosion. You will be recording what you see throughout the lab. It is important that you draw what you see, not what you think of when you think of a skittle or anything else. Scientists must draw what they see. 82
Biogeology Return to Table of Contents 83
Biogeology The biosphere is not only involved in shaping Earth through weathering, but also through animals and all living organisms which help to shape the environments around them. Biogeology is how life interacts with Earth. How do you think living organisms affect their environments? 84
Biogeology All living things affect the physical characteristics of the regions they live in. Here is one example. This is lichen, an organism that grows on rocks. It absorbs minerals from the rock, eventually causing the rock to break down. This lichen is 100's of years old. 85
Biogeology Humans change their environments in many ways. Humans plow fields, mine, and build buildings. What else can you think of that we do to change our environment? 86
Biogeology Plants also change their environments in many ways. Plants, like this tree, grow roots into the soil around them and they stabilize the soil. Can you think of anything else that plants do to change their environment? 87
Biogeology Animals also change their environments in many ways. One example is beavers; they build damns that change the flow of water just like humans do when they build dams. How else do animals change their environment? 88
Biogeology Although all living organisms change the environments around them, they also must respond as their environments change, sometimes from factors other than themselves (for example, because of plate tectonics). When an organism cannot adapt to changes in their environment, they will become extinct, meaning they will no longer exist. 89
Extinction This is what happened to the dinosaurs. Dinosaurs are extinct because they did not adapt to changes in Earth's environment many years ago. What are some theories on what happened in the environment that lead to their extinction? 90
Biogeology All living organisms must adapt to things in their environments, even as these organisms also change their environments. For example, humans change their environment by building big buildings. At the same time, it may snow in that environment and humans have to adapt and learn to live in those conditions. 91
Biogeology Rainfall Rainfall is one of the largest factors that determine which organisms can live in a region. Rainfall helps to shape land and it affects the types of living organisms found in a region. For example, in a desert with very little rainfall, you find cacti and lizards. You would not find big trees and tree frogs here. 92
Biogeology Rainforest But in a place with large amounts of rain, like a rainforest, you find many large trees and tree frogs. These plants and animals grow and live where they do because of rainfall. Some organisms have adapted to very little rainfall, like cacti, and some have adapted to live where there is lots and lots of rainfall, like these trees. 93
Biogeology As environments change, life forms need to respond and adapt to the changes. As humans have cut down trees to build more roads, we have changed the habitats of plants and animals. This has caused extinction of some species, death of animals and plants, and a shortage of resources. But sometimes we can take steps to help other organisms adapt to the changes we make in our environments. Click here to see a video on how humans have provided a structure to help animals adapt where there are major highways. 94
23 Biogeology is how rocks interact with Earth. True False Answer 95
24 As environments change, living organisms need to to the changes. A not respond B adapt Answer 96
25 Humans change the environments around them, but they do not have to adapt to their environments. True False Answer 97
26 When humans change their environments, can they sometimes help other organisms learn to adapt to those changes? Yes No Answer 98
27 Does rainfall help to shape the land and affect the type of living organisms found in a region? Yes No Answer 99
28 Only some living things affect their environment. True False Answer 100
Earth's System Walk In this activity, you will find evidence of weathering, erosion and biogeology in the world around you. 101