Weathering & Erosion

EQ: What causes rocks to change over time? LEARNING TARGET: Identify evidence of weathering and erosion to support how the Earth’s material changes. SUCCESS CRITERIA: I can revise my volcano model to show how Earth materials are broken down into smaller pieces.

VOCABULARY Dissolve - When a substance disappears (But is not destroyed). Example: When sugar is mixed in water or tea it dissolves. We cannot see it but we know it is still there because we can taste it. Melt- When enough energy is added to a solid it melts and changes into a liquid Example: A solid candle has thermal energy added causing it to melt into a liquid.

What is weathering? How does it affect rocks? Weathering is the process where rock is dissolved, worn away or broken down into smaller and smaller pieces. Weathering is caused by: Wind Rainfall Freeze-thaw cycle Animals & Plants What is the evidence? Temperature changes: when a rock gets hot it expands a little, and when a rock gets cold it contracts. Over time this causes cracks to form and pieces of rock to break away. Wind, rain: wind can blow tiny grains of sand against a rock, wearing it away (arch above). Rain lashing against a rock can also wear it away over long periods of time. Freeze-thaw: If water gets into a crack in a rock and then freezes, it expands and pushes the crack further apart. When the ice melts later, water can get further into the crack, which causes a piece of rock to fall off. Animals and plants allow water and air to reach bedrock or bring rocks to surface, exposing it to weathering.

What is erosion? How does it affect rocks? Erosion happens when rocks and sediments are worn away and moved to another place. Erosion is caused by: Glaciers Gravity Running Water Wind Waves What is the evidence? Glaciers erode rock as ice moves over it. Gravity causes erosion by pulling dirt, rocks and soil downward. Running water smooths rock over long periods. Wind drives waves to crash into rock, eroding it away.

Erosion of a Boulder

The Sun! UV, Light, and heat! What do you think is the main driving force of energy behind weathering and erosion? The Sun! Without the Sun the process of weathering and erosion would not occur. The Sun warms our planet, heating the surface, the oceans and the atmosphere. This energy to the atmosphere is the primary cause of our weather, creating wind (movement of air) that moves waves on the ocean and move tiny bits of rock against other rock that causes weathering. The sun drives the water cycle, including the development of clouds and rain. If you were thinking of gravity you would have been correct as it is also a major force that allows things to move on the surface of the earth, such as flowing water and falling rocks. UV, Light, and heat! What does our Sun provide to our planet (outputs of the Sun)?

Materials provided for each group of 3-4 students: Activity Supplies Materials provided for each group of 3-4 students: 1 plastic container 4 crayons of different colors 2 plastic knives 1 plastic plate 1 pipette 1 beaker with 20 mL water Moss plants 1 small plastic animal Yesterday in your notebooks you created a model of a volcano. Today we are going to revise the model on paper to include the processes of weathering and erosion. To help us understand these processes, we will also create a 3D model using crayon shavings. Each crayon represents a different kind of rock.

HOW IS SOIL PART OF THE ROCK CYCLE? TEAM HYPOTHESIS HOW IS SOIL PART OF THE ROCK CYCLE?

Weathering & Erosion Lab Write ALL answers & observations in your note book. Use the plastic knives to shave crayons over the plate. Answer Question 1: By cutting the crayons, what processes are you simulating? Form a small pile (Hill) of crayon shavings and a mountain of sand next to it. Blow gently on the mountains to simulate wind. Answer Question 2: What process does this represent? /RECORD OBSERVATIONS Sprinkle moss on your mountain because mountains have plants. Use a few drops of water with the pipette to simulate rain on the mountain. Answer Question 3: What process does this represent? /RECORD OBSERVATIONS Use the pipette to drop 1 mL of H2o at a time in the same spot until you have used 20 mL total to simulate a river. Answer Question 4: What process does this represent? /RECORD OBSERVATIONS Use the plastic animal to walk around the mountain & simulate how living things might affect your model. Answer Question 5: What process does this represent? /RECORD OBSERVATIONS What is sand? What happened to the plant/sand/water mixture when the animals walked on it? What is soil? Make a copy of instructions for each box.

Action: Record: Q1: Cutting the Crayons What process does this simulate? Record your observations. Q2: Blowing the sand & crayons Q3: Dropping the water droplets Q4: Dropping 20 mL of H20 in one spot Q5: Animals walking around the mountain Yesterday in your notebooks you created a model of a volcano. Today we are going to revise the model on paper to include the processes of weathering and erosion. To help us understand these processes, we will also create a 3D model using crayon shavings. Each crayon represents a different kind of rock.

Clean Up Your Table Place your shaved crayon pieces in the marked plastic container on the front table (we will save them for another activity). Dump the water into the marked pitcher on the front table, not in the garbage can.

Revise your Volcano Model Use your understanding of Weathering and Erosion to add to your Volcano Model Where is weathering and erosion happening? - Where does the broken rock and sediment move to on the Volcano? What symbols will you use? Yesterday in your notebooks you created a model of a volcano. Today we are going to revise the model on paper to include the processes of weathering and erosion. To help us understand these processes, we will also create a 3D model using crayon shavings. Each crayon represents a different kind of rock.

EXIT TICKET: Weathering & Erosion In your notebook, write: What is sand? What happened to the plant/sand/water mixture when the animals walked on it? What is soil?