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Further Investigations: Tide Prediction

  1. Practice estimating tidal range and heights. Here are some suggestions:
    1. Look at sessile (attached) shoreline organisms.
      1. Barnacles and oysters are usually submerged only at high tide. Look on walls, piles, and piers. The highest point where these organisms are found is a fair estimate of the high tide level.
      2. Algae attached to hard substrate, like rock, are exposed only during low tides; they can appear bleached white as a result of exposure during very low tides.
    2. Look at mollusk location and behavior on rocky substrate. The location patterns of mollusks are determined by their preference for being wet.
      1. Littorine mollusks prefer not to get wet, so they are found above the high tide water level in the splash zone.
      2. Nerite mollusks are usually covered by water during high tides.
      3. Limpets are exposed only during the very lowest tides.
    3. Use a guidebook to help you identify these mollusks.
    4. On sandy beaches, look for algae or floating debris left behind by waves that broke on shore during receding high tides. This debris marks the highest level reached by waves during a high tide. Look carefully for the wet sand level made by very recent waves.
  2. Investigate local tide conditions and patterns.
    1. Where is the closest government (e.g., National Oceanic and Atmospheric Administration) water level monitoring station in your area?
    2. Data from monitoring stations is available to the public online. Find the website for your local monitoring station.
    3. What is the average tide height in your area? 
    4. In addition to water level, what other information does your nearest monitoring station collect?
  3. How must loading docks, boat ramps, and bridges on navigable waters be designed or modified to allow for tidal changes?
  4. Look at a tide table for your area or for a region you might want to visit on vacation. What information other than tide level is given on the tide tables? Using the tide table, make a tide graph for a one-month period.

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Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.