The Very Spring and Root

An engineer's adventures in education (and other musings).

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Waves Project: Earthquakes and Tsunamis

[Note: Scroll down to the Files section for downloadable lesson/project materials.]

Background

I’ve been reading and learning a lot this year about the benefits of incorporating authentic tasks, project based learning, data, analysis, synthesis, and scientific discourse into the classroom. As we approach the end of the year, I’ve finally felt confident enough to try putting together my own project to fit with the principles I want to apply in my physics classroom.

Today is Day 1… I’ll post again with a reflection on how the whole thing goes.

This project is taking place about halfway through our unit on Waves — after mechanical waves but before electromagnetic waves. My hope is that students would be able to apply what they have learned to an authentic task that mimicked how science is really used to study the world and try to help people.

I want to emphasize that I am still near the end of my BTR residency year and M.Ed. program while designing this project. This is the first time that I attempted designing a project of this scale, and also the first time teaching it. I would definitely appreciate any feedback or suggestions for further refinement.

Project Overview

The project is based on the 2004 Sumatra Earthquake and Tsunami that devastated much of South East Asia. Students are given an introduction to earthquakes and tsunamis, provided with a project overview handout, and shown some video clips and photos.

Students are told that a massive earthquake and tsunami scenario has just occurred in the Indian Ocean, and that their lab groups are an investigative team that will be responsible for constructing a “What Happened” story using scientific analysis. Each team is assigned a particular city of interest: Banda Aceh (Indonesia), Chennai (India), Dar es Salaam (Tanzania), Mogadishu (Somalia), Padang (Indonesia), or Trincomalee (Sri Lanka).

The first part of the Work Packet involves background reading in the textbook 1, interpretation questions, and group discussion. The teams then receive two “technical memos”: one from the USGS National Earthquake Information Center, and one from the NOAA Tsunami Program. The data, properly interpreted, allow students to calculate the basic features of the earthquake p-waves and s-waves as well as some properties of the tsunami wave (such as arrival time at various cities, difference in speed and amplitude between open ocean and shore, etc). The third component of the project is an interpretation and discussion segment, followed by a final poster to present the final conclusions.

Design

This section describes my thought process and sources while putting together the project.

Lesson plans for every day of the project include silent individual work and think time. This is an access issue — many students prefer and may even require individual reflection and a chance to organize their thoughts before being ready to participate in group work.

I also have planned time into each day to allow for class-wide or group discussion designed to share information between groups, make sense of new vocabulary or concepts as a class, and engage in dialogue. Video clips, photographs, and eyewitness accounts from the real 2004 Sumatra disaster are also used to engage and interest students, as well as to maintain connections to the big ideas about how science is used in the real world.

Alignment With Standards

As per UbD philosophy, I started with the standards for which I wanted students to show evidence of applied knowledge. Based on where we were in the unit, I selected the following Massachusetts Physics Framework standards for focus:

  • 4.1 Describe the measurable properties of waves (velocity, frequency, wavelength, amplitude, period) and explain the relationships among them. Recognize examples of simple harmonic motion.
  • 4.3 Distinguish between the two types of mechanical waves, transverse and longitudinal.
  • 4.5 Recognize that mechanical waves generally move faster through a solid than through a liquid and faster through a liquid than through a gas.

And though they are not yet binding on BPS, I figured while I was at it to take a look at the relevant Next Generation Science Standards as well. I did not consider NGSS when designing the project; these suggested alignments are made in retrospect.

NGSS Dimension 1 – Practices2:

  • Practice 1 – Asking Questions
  • Practice 4 – Analyzing and Interpreting Models
  • Practice 6 – Constructing Explanations

NGSS Dimension 3 – Core Ideas3:

  • HS-PS4-1. Use mathematical representations to support a claim regarding relationships among the frequency, wavelength, and speed of waves traveling in various media.

 Technical Aspects

Nearly all scientific and technical information that I used concerning the physics of earthquakes/tsunamis, including how they are studied and measured, was found at the USGS Earthquake Hazards Program and the NOAA Tsunami webpages. Specifics for the 2004 Sumatra earthquake and tsunami, which formed the baseline data set I started from, were either directly on, or linked from, the USGS 2004 Sumatra quake page and the NOAA Center for Tsunami Research.

Earthquake p-wave travel times were estimated based on data from the USGS National Earthquake Information Center. S-wave arrival times were estimated using a base speed of 4.5 km/s, and then adjusted lower based on the distance from the epicenter to the arrival point. This accounts for the fact that both P and S waves move faster through the deeper layers of the earth.

My initial thought was to have students interpret a real seismogram trace from the USGS archives. However, I had to balance the complexity of teaching/learning all the features of a real trace with the objectives of the project. Since the point of the project was to learn about and apply knowledge of waves (not earth science per se), I decided to sacrifice some realism of the seismology aspect and focus on wave physics.

I made my own simplified seismogram trace in Matlab using a base sine function for each of the p-waves and s-waves. Wave parameters (amplitude, frequency) were taken from representative values for the Sumatra quake. Both waveforms were then perturbed with an additional, superposed sine wave with a randomized small amplitude, in order to give the waveform the look of “real” noisy data. I know it doesn’t quote look like a real seismogram trace would (especially the duration), but again, my focus for now was to see how they handle interpreting the wave information.

Tsunami arrival times were estimated from a simulated reconstruction of the wavefront propagation done by Japan’s AIST.

Surface distances from the epicenter (3.316°N, 95.854°E) to the selected cities of interest were calculated using the Latitude/Longitude Distance Converter from the National Weather Service.

Tsunami heights reaching the shores of the selected cities were eyeballed from a mix of published simulation results and from Googling eyewitness accounts and field reports.

Files

I would love to hear back from anyone who uses these! Feedback, comments, and areas for improvement would be greatly appreciated.

(Note: Only the most recent versions of each file are shown. The changelog is below, and see the comments thread for the thought process. I would be happy to share old versions by request, though bear in mind that there is usually a good reason I would take the time to update them.)

If you make use of these materials, please consider leaving a comment or contacting me with your thoughts. 

CHANGELOG:

v130522 – original project files

v130606 – revisions made after trying it on three blocks of junior-level high school physics:

  • Data: Earthquake waveform made more realistic. (Though this is still greatly simplified.)
  • Data: p/s-waves lumped together into body waves, then surface waves added.
  • Data: body wave arrival times distributed around assumption of  7.1 km/s
  • Data: surface wave arrival times distributed around assumption of 3.8 km/s (down from about 5 km/s)
  • Data: separation of non-related sentences (reduce confusion).
  • Work Packet: adjusted to ask for body waves and surface waves instead.
  • Work Packet: rephrasing to be more specific about what is being asked.
  • Rubric: tightened the difference between Partial and Acceptable (was very wide before)
  • Rubric: added point values
  • Rubric: more specific phrasings
  • Rubric: moved 5% of weight from poster to teamwork/participation
  • Added Matlab waveform generator .m script and .fig file. (You should be able to run this in Octave too if you change the % comment markers to #. The plot commands probably won’t work.)

Acknowledgements

Many of the resources available at Tools for Ambitious Science Teaching (particularly the Discourse Tools) were enormously helpful in the planning process for this project. Additionally, the GRASPS method of planning a rich learning task (part of the Understanding By Design framework) was used to lay out and organize the initial ideas, as part of the full UbD plan for the unit.

Also many thanks are due to my BTR co-resident Akil Srinivasan, my residency collaborating teacher Sotiris Pentidis (Boston Community Leadership Academy), and my clinical teacher educator Andrea Wells (Boston Teacher Residency).

 

Show 3 footnotes

  1. We are using CPO Science’s Physics: A First Course this year.
  2. I haven’t really sat down and scoured these for intended implementation. My claim of alignment is based on the summary descriptions in the Framework.
  3. As much as I love many aspects of the NGSS, I am disappointed that the Core Ideas dimension contains wave physics almost solely in a technology/application context. This is the only “pure” wave standard I found.


Lesson Plan: Intro to Parallel Circuits

I’ve been wanting to upload more lesson plans and materials that I think worked well — like everything else, its just a matter of finding the time.

BACKGROUND

The attached are a lesson plan and a handout for how I did the introduction to parallel circuits. At this point in the unit, we had already covered the conceptual understanding of what voltage, current, and resistance area. We had already covered Ohm’s Law as well, both activity-based and mathematically.

I have removed the following from the lesson plan:

  • Mention of or planning for individual students. Normally, in addition to planning for all students in general, I am preparing for particular students who tend to need additional prodding to focus, often have clarification questions, or perhaps need additional language assistance. 
  • The section on planning for individual students with learning disabilities, since the plans would necessarily detail confidential information about my students.

 

My students had not done series circuits yet. The decision to start with parallel came after some thought — I wondered if there are good reasons why series circuits a usually taught first. I really couldn’t think of any that didn’t also have an analog on the parallel side. For example, in a series circuit, it is usually intuitive why the current is the same through all components (there is only one path for the charges to take).

However, understanding why the voltage drops in a series circuit have to add up to the total battery voltage (proportional to their resistances) requires more thought (and a good understanding of what voltage physically is). On the other hand, in a parallel circuit, the idea that the current in each branch should sum to the total entering and leaving the battery is easy to visually demonstrate. But why should the voltage across all components never change, no matter how many you add or remove (within reason)?

I figured it was six one way, half a dozen the other and went with parallel first for the novelty.

FILES

These are free to use, modify, and distribute. Please credit me and/or this blog if you use it for something, and I’d love to hear any revision suggestions for next year or reports on how it went with other students! 

Lesson3.1A-ParallelCircuits [pdf]

Lesson3.1A-Handout [pdf]

ANALYSIS

Students in general pieced the important concepts together well. One thing that surprised me was that one group seemed to be able to use the data they were getting in the lesson to validate an incorrect model of parallel circuits: that it was always the closest resistor to the battery that got the most current. I realized 1) that this was not a student idea that I had anticipated, and 2) that the setup of the lab allowed this alternative conception to be reinforced (note that the resistor with lower resistance is, in fact, closer to the battery on the circuit diagram).

I asked that group to test out their idea by swapping the resistor positions, telling them to predict what would happen first. They conferred and said that “it was probably about fifty-fifty” on whether or not their theory would be disproven by the new data. They were able to discover that the current depends only on the relative value of the resistances.

I then reframed the post-activity discussion to center on this student reasoning/discovery instead of my originally planned questions. In a way, this was serendipitous — I got students to demonstrate for their peers what real science looks like. We have an initial model that attempts to explain something we observe, we ask ourselves what we need to do to validate that model, we attempt validation, and then revise our model. That meta lesson was possibly more important in the long run than the actual content of parallel circuits.

The next day, we followed up with discussion, reading, and applying mathematical relations to what we learned in the exploratory activity.




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