Central Idea and Summarizing: Ocean Waves

Read the Science Wire article, “Making Waves: How Wind Whips Up the Perfect Swell Opens a new window”. Open the link and read the entire article through once to get a sense of what the article is all about. Then reread the article as you complete the drag and drop activity below, or complete the alternative fill-in-the-blank activity. (This alternate activity is provided for students using keyboard only or screen readers.) Identify the central ideas and key details from different sections of the text that can be used to develop a summary. Note that you will identify the central idea for the text as a whole on the next page.

Did you notice a relationship between the central ideas and key details that you identified in the activity above? Determine which key details support particular central ideas. Click Show Answer to see if you are correct.

Show AnswerHide Answer

Central Idea	Supporting Key detail
A wave is motion moving through a body of water.	If you watch closely, you'll see that the water stays mostly in the same area; it's the disturbance caused by your breath that's moving across the water.
Winds push waves into each other, causing the waves to combine their energy and get larger and faster.	These waves will merge and become bigger still, as long as they have distance to cover and a way to sustain the energy that keeps them moving.
Tension and friction affects how much energy a wave has as it moves through the water.	If the storm that caused the waves didn't impart enough energy or create enough waves, then friction may take all the energy, and the waves will flatten out and dissipate before they get very far.
Favorable surfing swells are created by a lot of energetic waves.	There are three factors that contribute to the formation of good surfing swells: how fast the wind is blowing, the surface area of ocean that's affected by the storm, and the amount of time those winds blow over a given spot on the ocean.

Now that you have had some practice with central idea, review this skill on the next page.