Try It

Now that you have explored a process for determining the author’s purpose and how the author chooses the text structure(s) to serve the overall purpose, you will have a chance to practice your new understanding as you read the following text about tsunamis.

As you read, remember to ask yourself:

  • What does the author want me to learn?
  • What is the central idea in the article?  What is the BIGGEST idea that the author is presenting to the reader?
  • What is the most important information to be gained from the text AND the visuals?

You will be examining major sections in the text in order to trace the author’s purpose and the corresponding structure(s­­).  Read paragraphs 1 and 2 of the Tsunami article Opens a new window from the Centers for Disease Control and Prevention (CDC) website, and complete the follow-up activities.

What is a tsunami?

1 Tsunamis are giant sea waves. They can be caused by an (1) earthquake that occurs under an ocean, (2) by an underwater landslide, or (3) when a volcano erupts under water. Unlike the regular waves you might see at the beach or during a normal storm, tsunamis don't form on the surface of the water. They build energy as they move water within the ocean, sometimes as much as several miles deep!

2 Deep in the ocean, a tsunami's waves may only be a foot high. Since they can move at 300-600 miles an hour, by the time the waves reach the shallow water near the shore of islands or countries, the pent-up energy can make the wave(s) be as high as 80 feet tall. When it hits land, the waves' force will destroy anything in their way.