ERESE Teachers Log

Lesson title

This Restless Earth: Calculating Rates of Plate Motions

Intent of the lesson

  • To have students conduct on-line research to test a hypothesis, provide evidence to support their findings, and present their findings in a PowerPoint slideshow
  • To have students understand that magnetic anomalies and the age of rocks in the sea floor can be used to calculate the rate of tectonic plate motion

Ed. standards

National Science Education Standards for Grades 9-12:

The outward transfer of Earth's internal heat drives convection circulation in the mantle that propels the plates comprising Earth's surface across the face of the globe.

Lithospheric plates on the scales of continents and oceans constantly move at rates of centimeters per year in response to movements in the mantle. Major geological events, such as earthquakes, volcanic eruptions, and mountain building, result from these plate motions.

Scientists in different disciplines ask different questions, use different methods of investigation, and accept different types of evidence to support their explanations.

California State Standards:

Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:

a. Plan and conduct a scientific investigation to test a hypothesis.

b. Evaluate the accuracy and reproducibility of data.

Plate tectonics operating over geologic time has changed the patterns of land, sea, and mountains on Earth's surface. As the basis for understanding this concept:

a. Students know features of the ocean floor (magnetic patterns, age, and sea-floor topography) provide evidence of plate tectonics.

b. Students know the principal structures that form at the three different kinds of plate boundaries.

c. Students know how to explain the properties of rocks based on the physical and chemical conditions in which they formed, including plate tectonic processes.

Technology (ISTE) Standards:

Basic Operations and concepts:

Students demonstrate a sound understanding of the nature and operations of technology systems.

Students are proficient in the use of technology.

Technology Productivity Tools:

Students use technology tools to enhance learning, increase productivity, and promote creativity.

Technology Communications Tools:

Students use telecommunications to collaborate, publish, interact with peers, experts, and other audiences.

Technology Research Tools:

Students use technology to locate, evaluate, and collect information form a variety of sources.

Students evaluate and select new information resources and technological innovations based on the appropriateness to specific tasks.

Students use technology tools to process data and report results.

Technology Problem-Solving and Decision-Making Tools:

Students use technology resources for solving problems and making informed decisions.

Students employ technology in the development of strategies for solving problems in the real world.

Orientation

Introduce available tools and concepts so that students feel safe taking intellectual risks

Intent

Provide direction through general instructions in order to review students' prior knowledge of plate tectonics

Procedure

I will draw out student knowledge and comprehension of plate tectonics.

"Today, we will need to put on our "geologist hats" and think like an Earth Scientist."

The concepts that I will discuss include the following:

  • age of the earth
  • layers of the earth
  • tectonic plates
  • continental drift
  • earth's magnetism

Type of Evidence

Questioning

Teacher profile

3: I will ask questions such as:

  • What do you know about plate tectonics?
  • What are the layers of the Earth?
  • Tell me what you know about the layers of the Earth.
  • Can anyone tell me what "Continental Drift" is?
  • Tell me anything you know about magnetism.

Student profile

2: Students will demonstrate their knowledge about plate tectonics by sharing their responses to the questions listed above.

Fieldwork

Give students experience to foster their interest and ownership; provoke students to explore, observe, and generate their own questions about the phenomenon.

Intent

Guide students in focusing observations and allow for observation.

Procedure

1. I will divide the students into 6 groups of (ideally) 3. There could be 2 or 4 students per group.

2. I will instruct the students to go to the lab stations at which there are on-line computers, and have them go to the web site (listed below) to carry out the activities that are on the web site. Students will be given 2 days to complete the fieldwork activity.

3. Students will be asked to record their responses to all of the questions in the activity as well as their observations of the provocative phenomena.

4. Provocative Phenomena and Fieldwork Activity: go to This Restless Earth: An Internet Sampler on Plate Tectonics

5. Anticipated Observations:

  • what do the colors represent?
  • colors represent age
  • the colors are parallel to the spreading center
  • the sea floor is young in the middle of the sea floor and gets progressively older as it approaches the continents
  • the colors are symmetric across the spreading center but not exactly the same
  • the continents used to be all together about 200 mya and formed one big landmass
  • they moved to there present positions
  • how long did this take?
  • why did they move?
  • are they still moving?
  • How and why do the lithospheric plates move?
  • At what rate do they move?
  • How can this rate be measured?
  • Is this rate constant or does it vary?
  • Explain how the nature, or composition and structure, of the Earth's interior plays a role in this process.
  • How can the ocean floor be so much younger than the continents and the oceans themselves?
  • why is the earth magnetic?
  • what do the magnetic anomalies tell us?

Type of Evidence

Questioning that demonstrates a shift in the ownership of the question from me to the students.

Teacher profile

2: provide focus for observation and allow for adaptation. I will ask questions such as, "What did you notice?", "What did you wonder about?", What did you see?"

Student profile

4: Generates independent observations. Students should be asking questions like why did the plates move?, Are they still moving? How fast are they moving?

Debriefing

Teacher honors all student observations, questions and hypotheses in order to identify and discuss their viability as a research topic.

Intent

Facilitates learners in generating questions

Procedure

Ask each student to share their observations and write them up on the whiteboard.

Begin with observations about Activity #1 and go around the room until noone has anything new to contribute.

Encourage questions that begin with "I wonder about..." or "I wonder why.."

Continue with the above procedure until all of the activities have been covered.

Ask the students to look at the observations and observe common themes. Probable topics: Magnetic reversals, plate motion, speed of plate motion

Identify researchable questions:

  • At what rate do lithospheric plates move?
  • How can this rate be measured?
  • Is this rate constant or does it vary?

Type of Evidence

Probing questions

Teacher profile

1: Provides an opportunity to generate questions: What else did you notice? How are_____related?

Student profile

4: Students are able to generate questions and connect their observations and questions to the major themes by answering and elaborating on my probing questions.

Experimental design

1) Divide students into 6 groups of 3 to 4 students.

2) Next, students will gather the information that they will need to calculate the rate of seafloor spreading at assigned points on the Earth by using the Jules Verne Voyager Jr. website or the images from the resource matrices in the CEO or Earthref.org to address their questions. Each of the six lab groups will be assigned different points but will ask the same questions and have the same hypothesis. Students will record their data, methodology, data analysis, results, conclusion, and applications in a student log.

3) Next, students will be provided with a hard copy of a map of the seafloor that shows age and magnetic reversals. Using the "Surface Distance Between Two Points of Latitude and Longitude" web site, students will calculate the distance between magnetic reversals at their assigned point by noting the difference between latitude and longitude and converting it to distance. Once they find the distance between the magnetic reversals, they will go back to the map and find out how much time passed between the reversals. Now they will be able to calculate the rate of plate movement.

4) Once the students have finished these calculations, they should go back to their Internet based finding and compare/confirm the rates. The student log should include a discussion of this.

5) Students should then present a web page, poster, or power point slide show to share their findings.

6) Following all of the presentations, the teacher should ask the students what they noticed about the spreading rates at the different locations. They will probably notice that they differ. This could begin another brainstorming session about why and how this could be and could lead to another inquiry lesson!

Data collection

Define approach for collecting data

Intent

Assist each group in identifying the main concepts necessary to answer their questions as well as the procedure to be followed,

Procedure

The questions and hypothesis that the students will address are:

Researchable questions:

At what rate do lithospheric plates move?

How can this rate be measured?

Is this rate constant or does it vary?

Researchable hypothesis:

The plates move at a rate that can be measured by examining the magnetic anomolies and age of the rocks in the seafloor.

All of the materials needed for this experiment can be found at http://fc.ljcds.org/~sschissel/oceanmain.html

Possible Content Lessons:

  • Introduce students to the resource matrices
  • Review how to create a web page with Composer or Microsoft Word
  • Review how to modify an html document
  • Demonstrate the use of the Earthref.org

Type of Evidence

Questionning

Teacher profile

2: Guides students to the evidence to collect and how to collect it. What are you going after? What kinds of data will you need? Where will you get it?

Student profile

3: Guided to collect specific data. They will be guided to several Internet resources, but will be allowed to choose which objects will help them to answer their questions. They should be saying things like "What do we need?", "What facts address our topic?

Data analysis

From their hard copy map, students will convert change in latitude and longitude into distance.

This distance should be divided by the age difference between the magnetic anomolies to determine the rate of seafloor spreading.

Students should then compare these rates to the rates that they calculated or found explained from the web resources.

Intent

To guide the students to organize their findings in an experimental laboratory format and in data tables and to formulate explanations for their data.

Procedure

Students should organize their findings in an experimental laboratory format and in data tables

Type of Evidence

Questionning

Teacher profile

2: Guides student to analyze and interpret data

Student profile

3: Guided in process of formulating questions

Presentation

Teacher provides students an opportunity to prepare and communicate what they have learned.

Intent

The intent of the student powerpoint presentation is to provide the students the opportunity to present their work to each other and to the teacher.

Procedure

Each small group of students should create a powerpont presentation to communicate their findings to the rest of the class. They should refer to the rubric for guidance.

Possible Content Lesson

  • Guide the students through a PowerPoint tutorial

Type of Evidence

Student generated presentations

Teacher profile

2: Guides the students how to present their work "Please refer to the rubric"

Student profile

3:Guided throughout development of arguement and presentation