Plate Tectonics Box

Towers - Lesson Plan

Getting Ready

  1. Build your earthquake shake table (See Sources section).
  2. Prepare the sand bags.
  3. Do a trial run with a structure of your own design to see where students may run into trouble. Securing the structure to the foundation and securing the joints are two areas where students run into trouble.

Lesson Plan

Towers - Background

Teacher Background
I found this to be a great end of the year project when the kids are wiggly and not able to focus anymore on bookwork. They thoroughly enjoy the competitive nature of the challenge and get very involved in designing, building and redesigning their structures.

The student handout provided gives the criteria that I assigned to my students as well as a grading rubric. Briefly, the structures must meet the following requirements:

Towers - Logistics

Time
At least 2 hours to build structures and 5 minutes to test each one.

Grouping
Groups of 2-4 students.

Materials
Each group of students needs:

  • 1 cardboard base (approximately 25 cm by 25 cm)
  • 30 straws
  • 100 paper clips (one box)
  • 20 straight pins
  • 2 meters of string

Project - Earthquake Towers

Earthquake TowerEarthquake TowerSummary
In this project, students construct drinking straw towers that must withstand the shaking of a shake table. One by one, 250 gram sandbags are loaded onto the towers. The towers must remain standing for 1 minute from the start of the simulated earthquake. Students then have 2 minutes to repair any damage before another sandbag is loaded and the next earthquake test begins. Students quickly learn basic principles of earthquake engineering and architecture as well as the team skills that are a basic part of all science and engineering fields.

5. Seafloor Spreading - Sources and Standards

Sources
This activity combined the ideas from 1) a simple paper Seafloor spreading model by Ellen Metzger and 2) a more detailed shoebox Seafloor spreading model by John Lahr. Both lesson plans provide excellent background information and excellent alternative models.

5. Seafloor Spreading - Assessment

Assessment

  1. Ask students to answer the following questions for each of the 4 types of plate boundaries described in this lesson:
    • Describe how the plates are moving.
    • Give an example of somewhere in the world where you can find this kind of boundary.
    • Are there earthquakes?
    • Are there volcanoes?

5. Seafloor Spreading - Lesson Plan

Lesson Plan
Infer plate motion

  1. Review convection currents in the Earth’s mantle. Discuss how convection currents form and how they move. (The heat from the core causes mantle in some areas to rise while cooled mantle near the crust sinks.)

5. Seafloor Spreading - Getting Ready

Color coded and labelled world earthquake map: Original USGS earthquake epicenters map with mid-ocean ridges in orange, volcanic zones in red, and tectonic plate boundaries outlined in blue. See This Dynamic Planet website to download an unlabelled original.Color coded and labelled world earthquake map: Original USGS earthquake epicenters map with mid-ocean ridges in orange, volcanic zones in red, and tectonic plate boundaries outlined in blue. See This Dynamic Planet website to download an unlabelled original.

Getting Ready

  1. Make a copy of the Seafloor Spreading Model Pieces on cardstock paper for each student
  2. Set out scissors and colored pencils
  3. Remind students to bring their color coded World Earthquake Maps from Plate Patterns lesson
  4. At the front of the room display the large labeled world map from Plate Patterns lesson or a copy of the “This Dynamic Planet” poster from the USGS

5. Seafloor Spreading - Background

Teacher Background
Seafloor spreading is one of the most critical pieces of evidence in the development and support of the theory of plate tectonics. It is through this process that new oceanic crust is formed along the mid-ocean ridges as oceanic plates diverge and separate. Magma wells up into the gap, hardens, and forms new crust. As the plates continue to separate, these newly formed pieces of oceanic crust separate and make room, gradually moving outward away from the mid-ocean ridges at the rate of a few centimeters per year.

Subduction zone diagram: Image courtesy of NASA.Subduction zone diagram: Image courtesy of NASA.After several million years of this slow journey away from the mid-ocean ridges, the oceanic crust collides with a different tectonic plate in a process known as subduction. If the oceanic crust meets continental crust, the denser oceanic crust is forced under the continental crust. If the oceanic crust meets oceanic crust, then one or the other will be forced below the other. In these subduction zones, earthquakes are common due to the build up and sudden release of energy at the junction. Also, as the oceanic crust dives down below the other plate into the mantle, the old plate melts, forming a pool of magma that is forced back up through the crust above as volcanoes on the continent or a chain of volcanic islands on one side of the subduction zone.

In some instances, some continental crust is riding along on the oceanic plate and collides into another piece of continental crust. This is currently taking place in the Himalayas and was part of the process that created California (see the background section of Making California for more details). At these continent-continent convergent boundaries, the two sections of continental crust ram into one another, causing the crust above to buckle and fold into tall mountain ranges (the Himalayas and the Sierra Nevadas).

Using these patterns, students can infer both the direction and the relative speed each tectonic plate is moving. The following table shows all the plates and their approximate direction and speed.

5. Seafloor Spreading - Logistics

Time
30-50 min hypothesize plate motions
20-25 min build seafloor spreading models and discuss evidence
30-35 min study models and describe types of plate boundaries

Grouping
Inferring the direction of plate motion will occur in groups of 2 or 3. Making models of seafloor spreading takes place individually.