Ups and Downs

Student Worksheet - Analyzing Real-time Water Level Data from Monitoring Stations

NOAA Tides and Currents, managed by the Center for Operational Oceanographic Products and Services (CO-OPS), provides access to NOAA's vast collection of oceanographic and meteorological data (historical and real-time), predictions, and "nowcasts" and forecasts. Tides Online provides an easy way to view recent data from the National Water Level Observation Network, a network of 175 continuously operating water-level stations throughout the USA.

  1. Open the Tides Online Web page at http://tidesonline.nos.noaa.gov/. Click "State Maps," then on "MA" (Massachusetts) and select "Woods Hole." If at any point there are no data available, hypothesize on what might have caused this error. Is there unusual or severe weather at the monitoring station?
  2. How many high and low tides did Woods Hole, MA experience in the last lunar day? What type of tidal pattern did Woods Hole experience? What are the tidal heights in Woods Hole, MA?
  3. How do the observed and predicted data compare? What may have caused any differences between the observed and predicted data for Woods Hole, MA?
  4. Click the Back button twice on your browser or return to http://tidesonline.noaa.gov/geographic.html. "Click" on AL (Alabama) and select Dauphin Island, AL.
  5. How many high and low tides did Dauphin Island, AL experience in the last lunar day? What type of tidal pattern did Mobile experience? What are the tidal heights in Dauphin Island, AL?
  6. How do the observed and predicted data compare? What may have caused any differences between the observed and predicted data for Dauphin Island, AL?
  7. Click the Back button twice on your browser or return to: http://tidesonline.noaa.gov/geographic.html. "Click" on WA (Washington) and select Seattle, WA.
  8. How many high and low tides did Seattle, WA experience in the last lunar day? What type of tidal pattern did Seattle experience? What are the tidal heights in Seattle, WA?
  9. How do the observed and predicted data compare? What may have caused any differences between the observed and predicted data for Seattle, WA?

Conclusion questions:

  1. Summarize what causes tides. Discuss the effects of tidal forces and how bulges are formed.
  2. Explain why humans are interested in monitoring tides. What impact do tides have on human life? What impact might tides have on other organisms?
  3. Discuss how tides are monitored. Describe the old and new methods of monitoring tides.
  4. Compare and contrast the tidal patterns of Cape Cod, MA, Dauphin Island, AL, and Seattle, WA. What is the tidal pattern in your area?

Further Exploration:

Using the NOS Web site at http://tidesonline.nos.noaa.gov/geographic.html, select a tidal gauge that is located near your area. Monitor the tidal gauge for one month and record tidal fluctuations. Note any deviation from the predicted and observed tidal levels. What do you think causes this deviation?

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