Researching the Weathering & Erosion Processes
Lesson 14 of 16
Objective: SWBAT explain the weathering and erosion processes.
Inquiry Based Instructional Model
To intertwine scientific knowledge and practices and to empower students to learn through exploration, it is essential for scientific inquiry to be embedded in science education. While there are many types of inquiry-based models, one model that I've grown to appreciate and use is called the FERA Learning Cycle, developed by the National Science Resources Center (NSRC):
A framework for implementation can be found here.
I absolutely love how the Center for Inquiry Science at the Institute for Systems Biology explains that this is "not a locked-step method" but "rather a cyclical process," meaning that some lessons may start off at the focus phase while others may begin at the explore phase.
Finally, an amazing article found at Edudemic.com, How Inquiry-Based Learning Works with STEM, very clearly outlines how inquiry based learning "paves the way for effective learning in science" and supports College and Career Readiness, particularly in the area of STEM career choices.
In this unit, students will study each of Earth's major systems: biosphere, geosphere, hydrosphere, and atmosphere. In addition, students will investigate how these systems interact in multiple ways to affect Earth's materials and processes by conducting research, constructing graphs, creating models, carrying out scientific investigations, and analyzing real-world applications.
Summary of Lesson
Today, I open the lesson by showing a video on erosion and creating an anchor chart to compare the weathering and erosion processes. Students continue to explore the erosion process by gathering information from online resources.
Next Generation Science Standards
This lesson will support the following NGSS Standard(s):'
5-ESS2-1. Develop a model using an example to describe ways the geosphere, biosphere, hydrosphere, and/or atmosphere interact.
Scientific & Engineering Practices
For this lesson, students are engaged in Science & Engineering Practice:
Science & Engineering Practice 8: Obtaining, Evaluating, and Communicating Information
Students obtain ideas from an online text and a video. Students will then communicate their thinking in written form, using a graphic organizer.
To relate ideas across disciplinary content, during this lesson I focus on the following Crosscutting Concept:
Crosscutting Concept 2: Cause and Effect
Students evaluate cause and effect relationships as they learn how and why weathering and erosion occurs. For example, if water freezes in a crack, the water expands in solid form and causes the rock to break into pieces.
Disciplinary Core Ideas
In addition, this lesson also aligns with the following Disciplinary Core Ideas:
ESS2.A: Earth Materials and Systems
Earth’s major systems are the geosphere (solid and molten rock, soil, and sediments), the hydrosphere (water and ice), the atmosphere (air), and the biosphere (living things, including humans). These systems interact in multiple ways to affect Earth’s surface materials and processes. The ocean supports a variety of ecosystems and organisms, shapes landforms, and influences climate. Winds and clouds in the atmosphere interact with the landforms to determine patterns of weather. (5-ESS2-1)
To add depth to student understanding, when I can, I'll often integrate ELA standards with science lessons. Today, students will work on meeting CCSS.ELA-LITERACY.RI.5.7: Draw on information from multiple print or digital sources, demonstrating the ability to locate an answer to a question quickly or to solve a problem efficiently. In this lesson, students will be using multiple resources to locate key information involving the erosion process.
Choosing Science Teams
With science, it is often difficult to find a balance between providing students with as many hands-on experiences as possible, having plenty of science materials, and offering students a collaborative setting to solve problems. Any time groups have four or more students, the opportunities for individual students to speak and take part in the exploration process decreases. With groups of two, I often struggle to find enough science materials to go around. So this year, I chose to place students in teams of two or three! Picking science teams is always easy as I already have students placed in desk groups based upon behavior, abilities, and communication skills. Each desk group has about six kids, so I simply divide this larger group in half or thirds.
Gathering Supplies & Assigning Roles
To encourage a smooth running classroom, I ask students to decide who is a 1, 2, or 3 in their groups of three students (without talking). In no time, each student has a number in the air. I'll then ask the "threes" to get certain supplies, "ones" to grab their computers, and "twos" to hand out papers (or whatever is needed for the lesson). This management strategy has proven to be effective when cleaning up and returning supplies as well!
Now that students have learned about each of the Earth's spheres (biosphere, geosphere, hydrosphere, and atmosphere), I want to provide students with the opportunity to examine real-world applications using this new knowledge. For this reason, over a three-lesson period, students will research the weathering and erosion processes, construct a stream table model, analyze how the Earth's systems interact during the weathering and erosion processes, and use their understanding of systems interacting to investigate erosion control methods.
Day 1: Today, students research the difference between weathering and erosion. Then, they explore the erosion process further by researching online resources.
Day 2: Tomorrow, students will continue studying the process of erosion by observing a stream table model. Students will also examine how the Earth's systems are interacting during the weathering and erosion processes.
Day 3: On the final day, students will use their understanding of how the Earth's system interact during the erosion process to investigate the Dust Bowl and erosion control methods.
Lesson Introduction & Goal
I introduce today's learning goal: I can explain the weathering and erosion processes.
I want to inspire interest in today's lesson and capitalize on student curiosity, so I show the following video clip:
To encourage active listening during the video, I pause a few times for students to turn and talk about a particular question. For example, at 0:27, I ask students to turn and talk: What is erosion? (the removal of solid material by the force of moving wind or water) Later, at the end of the video, I ask students to turn and talk: How are the hydrosphere and geosphere interacting during the erosion process? (Sediment in the geosphere is carried downstream by rivers in the hydrosphere. The hydrosphere can carve away the geosphere over tens of millions of years of erosion to create grand canyons.)
Weathering & Erosion Poster
Often, the weathering and erosion processes are easily confused, so I want to create a simple anchor chart with students to help them differentiate between these closely related, but different, processes. Here's what the chart will look like at the end of this time: Weathering & Erosion Anchor Chart.
I invite students to join me at the front of the room with a red marker, blue marker, and their science journals. Some students sit on the carpet, while others gather around nearby desks. As I take notes on the class anchor chart, students also take notes in their journals: Student Notes on Weathering & Erosion.
I begin by writing and explaining: Today, we're going to talk about two processes... weathering and erosion. Weathering is the breaking down of Earth materials. For example, if a rock crumbles to pieces or breaks in half, this is called weathering.
Erosion, on the other hand, is the movement of Earth materials from one place to another. For example if a rock tumbles down a river, this is called erosion.
Whenever I think of weathering, I think of "wearing down," and whenever I think of erosion, I think of "transporting."
Turn and talk: How are the processes of weathering and erosion different?
Types of Weathering
Next, we discuss the three major types of weathering: 1) chemical, 2) biological, and 3) physical. Fore each type, I draw a little picture to help student visualize the process.
For chemical weathering, we discuss how oxygen and water react with rocks containing iron. The rock is chemically altered or changed, causing the rock to become reddish and crumbly.
Students then said, "I know an example of biological! That's when a plant or animal breaks rocks." You're right! I then drew a picture of tree roots breaking a rock and connect this to the fact that tree roots are so powerful that they can cause large cracks in sidewalks.
For physical weathering, I take the opportunity to explain the process of ice-wedging: Has anyone placed a full water bottle in the freezer before? What happens? (The water expands as it freezes, causing the water bottle to take on a new shape.) Here in Montana, we have rocks everywhere with different sized cracks. If a crack fills with water, what do you think happens when the temperature drops? (It gets cold and freezes, which means the water will expand.) What do you think happens when the water freezes? (It expands and causes the rock to break.)
I provide one more example of physical weathering using a piece of sandpaper and a rock. Sand Paper & Rock: What is sandpaper made out of? (sand and paper) What is rubbing against the rock as I move it back and forth on the sandpaper (little pieces of sand) In a river, rocks rub up against each other all the time. This is called abrasion. Pointing to the find particles of rock that were rubbed away by the sand paper, I ask: Do you see how the sand wears away the rock? Students respond, "Oh yeah...!"
To balance teacher instruction with student conversations, I ask students to turn and talk: Which type of weathering do you think wears down the geosphere the most?
Forces of Erosion
Moving on to the forces of erosion, we discuss four major forces that cause material to move from one place to another. I begin by asking, What do you think is powerful enough to move sediment from one place to another on Earth? One student says, "Water!" We then draw a picture of a river and discuss how different sized rivers carry different sized sediment downstream.
Then a student offers, "Wind can transport sand!" We then draw a picture of wind picking up sediment and transporting it to a new location.
I provide students with a clue for the next erosional force: The next force is an example of a water in a solid form. Students eventually come up with glaciers! We then discuss how glaciers will advance down a valley when its cold and during warmer temperatures, it will retreat back up the valley. In doing so, the glacier will deposit sediment as it melts, often leaving big boulders out in the middle of nowhere!
Finally, we discuss gravity as an erosional force. We review that gravity is a force on Earth that pulls objects downward. Sometimes, after a rock as been worn down and weakened, gravity eventually pulls the rock downhill. We also discuss how gravity pulls rock downward during landslides.
Before moving on, I ask students to turn and talk: Explain the variety of ways a rock might be transported from one place to another.
Getting Ready to Research
At this point, I ask students to grab their laptops (one computer per student) and return to their desks so that we can move on to researching the process of erosion.
I pass out the following graphic organizer to each student and model how to write the main idea in the center, "Erosion." I ask students to turn and talk: What questions do you still have about erosion? Students thoughts include, "Where does erosion happen the most?" and "Which causes erosion more - wind or water?"
For today's research, I ask students to work in groups of two. While I normally ask students to share one computer in order to encourage a higher level of collaboration between the two students, I decide to mix it up a bit today! Students are excited to be able to use one-to-one technology and promise that they will focus on working together and sharing ideas!
By providing students with a variety of resources (both a text and a video), I'm also allowing greater access to information to a range of students. Some students learn best by reading text while others learn best from listening or watching.
Monitoring Student Understanding
Once students begin researching the process of erosion with their partners, I conference with every group. My goal is to support students by asking guiding questions (listed below). I also want to encourage students to engage in Science & Engineering Practice 7: Engaging in Argument from Evidence.
- What patterns have you noticed?
- Why do you suppose ____?
- What have you found so far?
- Has your thinking changed?
- What evidence do you have?
- How did you decide _____?
- What conclusion can you draw about ____?
- How is the ____ (sphere) interacting with the _____ (sphere)?
During this conference, Students Discussing Erosion in Dry Areas, I encourage the students to think about how the hydrosphere (amount of precipitation) and biosphere (vegetation) impact the erosion process and the geosphere.
Here, Students Discussing the Earth's Spheres, the students come up with ways that the atmosphere, hydrosphere, and biosphere interact with the geosphere during the process of erosion.
Almost all students were able to complete their graphic organizers. Here are a few examples of student work during this time:
Tomorrow, students will continue exploring erosion by observing a stream table model and examining the interactions between Earth's systems during the erosional process.