DUCK Lab: Waves & Bars

Go to File, New beach, Duck.

Duck web site.

Start by looking at the Waves for the period 1985 to 1991.

• Waves, Period shows the waves at intervals of several hours. You can right click on the image and rescale the diagram to focus on a small part of the record.
• Waves, Height shows the waves at intervals of several hours. You can right click on the image and rescale the diagram to focus on a small part of the record.
• Waves, Statistics will give you a series of windows:
  • A wave statistics table. The average value for each month is given. The annual average is on the right of the table, and the monthly averages are on the bottom.
  • A wave height distribution graph. This shows the shape of the Rayleigh distribution. You should compare the mean (from the statistic table) with the mode (the peak of the distribution, the most frequently occuring value).

  

  • A graph of average monthly wave heights. You can right click on the graph and select the "Annual cycle" check box. This will give a graph like the one below.

  

  • A graph of average monthly wave periods. You can get the annual cycle on this as well.

Use the Tides, Storm Surge to see a year's worth of data. Positive numbers mean the tide was higher than predicted, and negative numbers that it was lower.

Then look at the beach Profiles for the period 1981 to 1991:

There are four profile lines surveyed at Duck. You should always select the profile line that you are using.

• Profiles, Graphs: shows beach profiles. The vertical scale is elevation, with sea level as 0. The horizontal scale starts at a point behind the dune, when the bench mark is safe from all but the worst storms. On the options tab you can pick the color of the profiles, and whether they all plot with the same vertical scale or whether each drops down. You can right click and rescale the graph. You can pick individual profiles, or all that match a given month.
• Profiles, Difference:
• Profiles, Average:
• Profiles, Envelope:
• Profiles, Data Points:
• Profiles, Oblique: a 3D view with distance from the datum, vertical elevation, and time running into the page. The view is color coded by month as well as being labeled.

• Shoreline Position: a graph showing the shoreline (elevation 0) position over time. The position is measured from the Bench Mark behind the dune.
• Varying position:
• Movie: watch a time series of the profiles. The color envelope shows the range of the profiles measured over the 10 year period. The highlight shows the current profile, whose date (YYMMDD) is show both in the lower right in small letters, and on the panel at the bottom of the window. You can use the VCR controls to step through the time series.

Last revised 9/14/2005