How Do Tides Work?
ES2406  Observing Tides at Cape Porpoise Harbor, October 17, 2001

The animation below displays a sequence of photographs showing tidal changes at Cape Porpoise Harbor, Maine between 6:00 A.M. and 6:00 P.M. on October 17, 2001.

  !   Click the image to watch the animation. Observe carefully to see a boat that is affected by the tide. The tide chart on the right tracks time and tide levels through the day.

Photographs: www.maineharbors.com.
Tide chart: Tom Grace, TERC, Adapted from: © 1996 N. Dean Pentcheff
for the WWW presentation at http://tbone.biol.sc.edu/tide and
© 1998 David Flater for the XTide program
at http://www.flaterco.com/xtide
 

4. Describe the changes in tidal levels that occurred on October 17. At what times did the highest and lowest tides occur?

5. There are roughly two high tides and two low tides every 24 hours. At what time do you think the next high tide occurred?


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