Look for: When a strong, shallow earthquake happens and…

3.A.3 Analyze and interpret data from different wave models to identify patterns in how the wave forms initially and moves toward shore, changing height (amplitude) as it interacts with the ocean floor.

After analyzing the Tsunami Wave Model, listen for students to identify the following key ideas:

• When a strong, shallow earthquake happens and causes part of the ocean floor to move up and another part to move down (vertically), a tsunami can happen.
• These waves move out from the location where the ocean floor moves.
• The height (amplitude) of the waves that are farther out in the ocean (closer to the epicenter) is less than the ones that reach the shore.
• As the waves move toward the shore where the water above the ocean floor is shallower, the amplitude increases.
• When the wave reaches shore, it seems to fall over itself and spread out or run up onto the land.
• The bigger the wave that reaches the shore, the more it will move onto land.

Some students may struggle with recording observations while watching, as this visualization model changes perspectives and location of what is being represented. It may help to play the video once all the way through, telling students to simply watch and not take notes. Then play it a second and perhaps a third time, pausing at incremental places to allow students to reflect on three segments of the model as they record their observations: The beginning of the video shows the ocean floor snapping and breaking, then a flyover shows the wave moving out from the epicenter. The next part shifts to show how the wave amplitude changes as the water above the ocean floor becomes shallower. The last part shows the wave reaching the shore. . Another option, if the technology is available, is to watch the video once as a class and then have students play it again in small groups to make observations.

Combine analyses of the third model and connect to tsunamis. Show slide K. Say, What were some connections you and your partner made between the model and how an actual tsunami behaves? Ask a few pairs to share what they discussed and encourage students to add to their handout if they hear ideas they agree with but have not recorded. Some students may wish to have you play the Tsunami Wave Model again so they can come up and point out things they discussed with their partner.