8.3.1.2 Landforms

Grade: 
8
Subject:
Science
Strand:
Earth & Space Science
Substrand:
Earth Structure and Processes
Standard 8.3.1.2

Landforms are the result of the combination of constructive and destructive processes.

Benchmark: 8.3.1.2.1 Causes of Landforms

Explain how landforms result from the processes of crustal deformation, volcanic eruptions, weathering, erosion and deposition of sediment.

Benchmark: 8.3.1.2.2 Surface Processes in Minnesota

Explain the role of weathering, erosion and glacial activity in shaping Minnesota's current landscape.

Overview

Standard in Lay Terms 

MN Standard in Lay Terms

The surface of the earth is shaped by processes such as volcanic activity and tectonic activity that cause areas to be forced upward, and by the gradual removal of earth materials by weathering and erosion.  In Minnesota, the current landscape is largely the result of the scraping away of materials by advancing glaciers and the deposition of sediments by retreating, melting glaciers.

Big Ideas and Essential Understandings 

Big Idea

Students need to understand that although changes to the earth's surface are so slow that it may seem unchanging, constructive and destructive processes are constantly at work.  The surface of the earth actually changes quickly when viewed on a geologic timescale.

By the end of the 8th grade, students should know that:

  • The interior of the earth is hot.  Heat flow and movement of material within the earth cause earthquakes and volcanic eruptions and create mountains and ocean basins.  Gas and dust from large volcanoes can change the atmosphere. 4C/M1
  • Some changes in the earth's surface are abrupt (such as earthquakes and volcanic eruptions) while other changes happen very slowly (such as uplift and wearing down of mountains). 4C/M2a
  • The earth's surface is shaped in part by the motion of water (including ice) and wind over very long times, which acts to level mountain ranges.  Rivers and glacial ice carry off soil and break down rock, eventually depositing the material in sediments or carrying it in solution to the sea. 4C/M2b*
  • Sedimentary rock buried deep enough may be re-formed by pressure and heat, perhaps melting and recrystallizing into different kinds of rock.  These re-formed rock layers may be forced up again to become land surface and even mountains.  Subsequently, this new rock too will erode. Rock bears evidence of the minerals, temperatures, and forces that created it. 4C/M4
  • Thousands of layers of sedimentary rock confirm the long history of the changing surface of the earth and the changing life forms whose remains are found in successive layers.  The youngest layers are not always found on top, because of folding, breaking, and uplift of layers. 4C/M5
  • Human activities, such as reducing the amount of forest cover, increasing the amount and variety of chemicals released into the atmosphere, and intensive farming, have changed the earth's land, oceans, and atmosphere.  Some of these changes have decreased the capacity of the environment to support some life forms. 4C/M7
  • There are a variety of different land forms on the earth's surface (such as coastlines, rivers, mountains, deltas, and canyons). 4C/M8** (BSL)
  • The earth's plates sit on a dense, hot, somewhat melted layer of the earth.  The plates move very slowly, pressing against one another in some places and pulling apart in other places, sometimes scraping alongside each other as they do.  Mountains form as two continental plates, or an ocean plate and a continental plate, press together. 4C/M12** (BSL)
Benchmark Cluster 

MN Standard Benchmarks

8.3.1.2.1  Explain how landforms result from the processes of crustal deformation, volcanic eruptions, weathering, erosion and deposition of sediment.

8.3.1.2.2  Explain the role of weathering, erosion and glacial activity in shaping Minnesota's current landscape.

The Essentials

 From: The Book of Biff

Correlations 

NSES Standards:

  • NSES Content Standard D Earth and Space Science
  • Structure of the earth system
  • Land forms are the result of a combination of constructive and destructive forces.  Constructive forces include crustal deformation, volcanic eruption, and deposition of sediment, while destructive forces include weathering and erosion.
  • Changes in earth and sky
  • The surface of the earth changes.  Some changes are due to slow processes, such as erosion and weathering, and some changes are due to rapid processes such as landslides, volcanoes, and earthquakes.
  • Origin and evolution of the earth system
  • Interactions among the solid earth, the oceans, the atmosphere, and organisms have resulted in the ongoing evolution of the earth system.  We can observe some changes such as earthquakes and volcanic eruptions on a human time scale, but many processes such as mountain building and plate movements take place over hundreds of millions of years.
  • AAAS Atlas:
  • National Science Digital Library (NSDL) Science Literacy Maps: The Physical Setting; Changes in the Earth's surface.
  • Benchmarks of Science Literacy:
  • At this level, students are able to complete most of their understanding of the main features of the physical and biological factors that shape the face of the earth.  This understanding will still be descriptive because the theory of plate tectonics will not be encountered formally until high school.  Of course, students should see as great a variety of landforms and soils as possible.
  • It is especially important that students come to understand how sedimentary rock is formed periodically, embedding plant and animal remains and leaving a record of the sequence in which the plants and animals appeared and disappeared.  Besides the relative age of the rock layers, the absolute age of those remains is central to the argument that there has been enough time for evolution of species.  The process of sedimentation is understandable and observable.  But imagining the span of geologic time will be difficult for students.

Misconceptions

Student Misconceptions 
  • Erosion is the only process that alters the appearance of the earth.
  • All changes to the earth's surface occur suddenly and rapidly.
  • All events that affect the earth are gradual or slow.
  • All earth processes operate at the same rate (on the same time-scale).
  • All changes to the earth occur so slowly that they cannot be detected during a human lifetime.
  • Mountains form when earthquakes push the ground up.
  • Earthquakes cause all volcanic eruptions.
  • Volcanic eruptions cause all earthquakes.

Bibliographic Citation

Ford, B. and Taylor, M. (2006). Investigating Students' Ideas about Plate Tectonics. Science Scope, 30(1), pp 38-41. (note: NSTA members can access this article on line through the NSTA Journal Archives at nsta.org)

Vignette

Ms. F. has addressed this standard throughout the school year with a variety of lessons and activities.  Students have an understanding of destructive processes of weathering and erosion and the constructive processes of volcanism, deposition, and the changes to the earth's surface caused by the forces of plate tectonics.  Ms. F. knows that because this standard is addressed in many parts over the course of the year, it is important to bring it all together and to make sure that there are no enduring misconceptions.  Ms. F. uses a current geologic event, a large earthquake that has been in the news, as a starting point for discussion.  In small groups, students discuss how they can explain what might have caused the earthquake based on what they have learned this year.  Keeping in mind the misconceptions they may have, the teacher circulates and asks questions to engage the students.  As the students share their ideas, Ms. F. guides the discussion to make sure that the misconceptions are addressed and reinforces the students' correct ideas.  This standard is a big idea which brings together many other ideas and the discussion helps the students to synthesize the information they have been learning all year. (Hoffmann, 2011)

Resources

Instructional Notes 

Suggested Labs and Activities

  • Activities and lessons for 8.3.1.1 and 8.3.1.3 also are important in the understanding of this standard.
  • Stream tables help students understand the movement of material by water.  The PDF from the Exploratorium was developed to teach teachers about inquiry, but presents some excellent ideas that can be used for a successful stream table experience in the classroom as well. (8.3.1.2.1)  
  • Weathering Lab Stations designed to identify various types of weathering and erosion.  Discover the effects that occur with each type of weathering and erosion.  (8.3.1.2.1) 
  • In this lesson, students will learn about how the Grand Canyon was formed, focusing on how the process of erosion enabled its rock layers to be deposited. They will examine the canyon's layers to see what the area probably looked like when the layers were created.  (8.3.1.2.1) 
  • A webquest type activity designed by the American Geological Institute.  Many of the resources could also be used independently of the webquest activity.  (8.3.1.2.1) 
  • Many animations designed to increase understanding of dynamic earth processes.  (8.3.1.2.1)
  • Towel Geology.  Designed as a demonstration, this might also work well as an alternative assessment of activity allowing students to demonstrate the concepts that they have learned. (8.3.1.2.1)
  • Various educational resources from the Minnesota Geological Survey, including the virtual egg carton of rock samples and maps.
Instructional Resources 

Instructional Suggestions/Options

Seeing a variety of landforms shaped by different processes is helpful to broaden the perspective of the constructive and destructive processes and the concept of a landform.  This standard encompasses many major earth science concepts, many of which will involve hands-on activities to build understanding of the processes that shape the earth's surface.  Additionally, there is a great deal of vocabulary associated with these topics which should be used and encouraged.

New Vocabulary 

Vocabulary/Glossary

  • Chemical Weathering: the breaking down of rocks and minerals that result from processes that cause a change in their chemical composition.
  • Cliffs: a steep rock exposure caused by physical weathering.
  • Constructive Processes: processes which build up or uplift the land at the earth's surface.
  • Crustal Deformation: changes to the crust of the earth caused by plate tectonics.
  • Deposition: the dropping of materials moved by erosion in a new location.
  • Destructive Processes: processes which break down and move the materials that make up the earth's surface.
  • Erosion: the movement of loose earth materials from one location to another; agents of erosion include water, wind, ice, and gravity.
  • Flood Plain: the land around a river that is covered by water during a flood.
  • Glacier: a mass of snow and ice that moves slowly due to the force of its weight; may be alpine or continental.
  • Lakes: a lower-lying area where water collects that is surrounded by land.
  • Landform: features that make up the shape of the land at the earth's surface.
  • Moraines: unsorted rock and soil left when a glacier melts and retreats.
  • Physical Weathering: the breaking down of rocks and minerals into smaller pieces.
  • River Valleys: the area through which a river flows; generally V-shaped due to weathering and erosion by the river.
  • Sediment: loose materials that have been transported through erosion, including pieces of rock, mineral fragments, and organic matter.
  • Uplift: a process that causes an area of the earth's surface to be pushed upward by tectonic forces.
  • Volcanic Eruptions: lava and volcanic ash moving onto the earth's surface, resulting in the formation of new igneous rock.
  • Weathering: the breaking down of rocks and minerals by natural processes.
Technology Connections 
  • A Smithsonian website contains excellent graphics and explanations of the dynamic earth.  (8.3.1.2.1)
  • A webquest designed to help students develop their understanding of plate tectonics.  The site includes extensions and enrichment opportunities.  (8.3.1.2.1)
  • Glacial erosion and deposition; much of the animation focuses on alpine glaciers, but there is some information that would be of value.  (8.3.1.2.1)
  • Weathering animation; some of the concepts are a little advanced for 8th grade, but there are very good descriptions and animations of many 8th grade concepts.  (8.3.1.2.1)
Cross Curricular Connections 
  • Math
    • Construction of a to-scale geological timeline requires scale factors.
References 

Additional resources

Assessment

Assessment of Students

From: Keeley, P., Eberle, F., and Tugel, J. (2007). Uncovering student ideas in science-25 more formative assessment probes. Arlington, VA: NSTA Press (available at nsta.org; also available through amazon.com).

  • Mountaintop Fossil: This probe targets student ideas related to changes in the surface of the earth.  The probe can be used to examine student work related to the idea that marine fossils found on top of tall mountains can be explained by earth processes.

Assessment of Teachers

Questions could be used as self-reflection or in professional development sessions.

  • The earth is often described as dynamic.  What does that mean?  How might you explain it to students?
  • The earth's surface features are a result of constructive and destructive processes.  What are these processes?
  • What is geologic time and why is it important for students to understand?

Differentiation

English Language Learners 

According to Lee & Buxton (2010), a couple of approaches are useful for assisting English Language Learners (ELLs): teach content while fostering language development and draw on the so-called "funds of knowledge," which are students' personal experiences from home or community.  For additional details on this see the original NSTA News posting and the official NSTA position statement.

Extending the Learning 

Students who have mastered the concepts may be challenged to investigate and try to determine the geologic history of a landform in their area, or one with which they are familiar, using geologic maps and other resources.

Special Education 
  • This website has many for specific classroom suggestions for Sp Ed, ELL
  • Official NSTA position statement on students with disabilities.
    • There is a lot of vocabulary that is necessary for understanding this standard.  Many of the terms can be represented in picture form as well, which helps all students to learn and make connections between what they know and new vocabulary.
    • Assessment is flexible with a standard such as this because it is bringing together and making connections between several large concepts, and it is possible for students to show their understanding in a variety of ways, drawing on their individual strengths.
    • Books and other resources addressing landforms are available at all reading levels and various depths of understanding.  With the assistance of the school librarian, it should be possible to have a wide range of materials available for student use in the classroom during a landforms unit.

Parents/Admin

Classroom Observation 

Administrators

Administrators observing a lesson on this standard what might they expect to see students working with stream tables, rocks, sediments and other materials related to understanding weathering and erosion.  A lesson might also include physical models of volcanoes and plate boundaries or maps tracking volcanic and earthquake activity around the world.  Online simulations and diagrams also help aid student understanding of these concepts.

Parents 

For many parents, plate tectonics may not be something that they learned about in school.  Ask that students teach their parents about this theory.