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Activity: Sendai, Japan Tsunami Animation

NGSS Science and Engineering Practices:

NGSS Crosscutting Concepts:

NGSS Disciplinary Core Ideas:

Paid
Teacher Guide

Sendai, Japan Tsunami Animation Activity Teacher Guide 11-2017 with table.pdf

On March 11, 2011, a tsunami was generated by a 9.0 magnitude earthquake. The earthquake was centered 130 km off the east coast of Sendai, Japan. The 9.0 magnitude earthquake was the biggest earthquake ever measured in Japan, and many large aftershocks followed the main event. Buildings in Japan were damaged by the main earthquake and by the aftershocks. The nuclear power plant at Fukushima was also damaged.

 

The highest tsunami waves reached the coastline of Japan about 30 minutes after the earthquake occurred. The tsunami added to the damage caused by the earthquakes. The tsunami also had widespread impact across the Pacific ocean basin.

 

Materials

  • Table 5.13
  • A globe or map of the Pacific ocean basin
  • Computer with internet access
  • Graphing paper or graphing program
  • Table 5.12

Procedure

  1. Using a globe or map of the Pacific ocean basin, locate Sendai, Japan.
    1. Choose a location on the other side of the Pacific ocean basin (on the North or South American continent). Envision an imaginary line between Sendai and your location.
    2. Use google maps, a globe, or map with a scale bar to determine the distance between the two locations.
  2. Assume that a typical tsunami travels at about 750 km/hr. Estimate how long it will take for the tsunami wave to reach your chosen location.
  3. Predict how the energy of the earthquake will propagate across the Pacific ocean basin.
  4. Tsunamis form waves in sets that radiate from their point of origin, like the ripples caused by throwing a rock into a pond. Predict what will happen to the height of the tsunami waves as they travel from Sendai to your location.
  5. The National Oceanographic and Atmospheric Administration (NOAA) has posted a Wave Energy Map of the tsunami (See Fig. 5.33.1 A)
    1. Go to website https://www.coast.noaa.gov/psc/dataviewer/#view=japanEnergy to view the wave energy map.
    2. Describe the pattern of waves and their relative and height as they move across across the Pacific ocean basin.

<p><strong>Fig. 5.33.1 B.</strong> Tsunami with start/pause button and hour timescale bar with tick marks (each mark is 1.3 hours)</p><br />

  1. NOAA has also developed an animation that shows the Sendai tsunami moving across the Pacific.
    1. Go to the website: https://www.coast.noaa.gov/psc/dataviewer/#view=japan11.
      1. This is the tsunami animation view. You can switch between the Tsunami Animation and the Wave Energy Map by clicking the button in the upper right corner. However, the labels are confusing. When you are in the Wave Energy Map, the button shows Tsunami Animation (because you click the button to go to the animation). See the labels in Figs. 5.33.1 A and B.
    2. Familiarize yourself with the animation controls (Fig. 5.33.1 B).
      1. Use the hand tool to rotate the globe to view different areas of the Pacific ocean basin.
      2. Practice starting, pausing, and restarting the animation.

<p><strong>Fig. 5.33.1 A. </strong>Wave Energy Map view, showing hand tool that lets you rotate the globe</p><br />

  1. Use the animation to observe and record how a tsunami impacts the Pacific ocean basin.
    1. Run the animation to determine the time that the tsunami reaches your chosen location.
      1. Use the timescale below the animation. Each tick mark is equal to approximately 1.3 hours. (see Fig. 5.33.1 B).
      2. Record the time the tsunami reaches your chosen location in the observation column of Table 5.13.
    2. Record the highest estimated height of the leading edge of the tsunami wave as it moves across the Pacific for 24 hours.
      1. Run the animation again, stopping every 1.3 hours (each time the timeline reaches a new tick mark).
      2. You will need to rotate the globe using the hand tool to continue to be able to see the leading edge of the wave.
      3. You will need to estimate the wave height based on the color scale.
        1. The crest of the leading wave is positive in height and colored yellow-orange-red. The trough between the waves is negative, because the trough of the waves is lower than the average sea level.
        2. Note that the wave height will not change dramatically over time, but it does change! Watch carefully!
        3. Your estimate will be based on the color scale bar, which does not have a lot of differentiation (see Fig. 5.33.1 B). Do your best to estimate the wave height.
    3. Observe and record any other general observations about the tsunami wave and the patterns of the waves as they move across the Pacific.
      1. Run the tsunami animation again without pausing for at least 48 hours.
      2. Notice how the tsunami moves in the open ocean compared to how it moves near islands and continents.
      3. Record additional observations in the observation column of Table 5.13 or in the space below the table.
  2. Using graph paper or graphing software, create a graph of wave height versus time from the data you collected in Table 5.13. Label your graph appropriately.
Activity Questions: 
  1. Compare your predictions about each of the following to your observations.
    1. Wave height
    2. Time needed to reach destination
    3. Wave energy

If your predictions were close to your observations, explain what prior information helped your form your prediction. If your predications were different than what you observed, describe what additional information would have been useful in generating a more accurate prediction.

  1. Were there any changes in wave height as the tsunami propagated, or spread, across the ocean? If so, explain how the wave height changed.
     
  2. Did you observe any wave boundary behavior or interference patterns? If yes, explain what patterns you observed and where they occurred.
     
  3. Reflect on your observations in this activity. Think about the long wavelength of a tsunami wave and the fact that tsunami wave energy often touches the ocean floor. What factors do you think affect how a tsunami propagates through an ocean basin?
     
  4. As tsunami waves travel across the deep open ocean, they are usually no more than 30 cm high, which means ships cannot detect tsunamis passing beneath them. Explain why these relatively short tsunami waves can form large waves, and large walls of water, as they come to shore.
     
  5. Even though the tsunami warning system worked well, the death toll, environmental damage, and economic cost of the 2011 Japanese tsunami were extremely high. Explain why you think this might be.
     
  6. The 2011 Japanese tsunami breached high breakwater walls surrounding coastal cities. What other technology or coastal engineering options might people in low-lying coastal areas want to consider to mitigate the effects of tsunami? (Refer to Table 5.12 for examples of structures human can build along shorelines.)

Table of Contents:

Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.