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Dr. Megan Dethier

Dr. Susan Williams

University of Washington University of California-Davis
Friday Harbor Laboratories Bodega Marine Laboratories


Sample Intertidal Temperature Graphs

Midnight vs. Noon Daily Temperatures

Davison Head High Temperatures at Noon and Midnight Davison Head Mid Temperatures at Noon and MidnightBack to top

In the San Juan Islands, at any given point on the rock, the total number of hours per day of exposure to air remains fairly constant throughout the year (ca. 50% of the time at the High level, 22% at the Mid). However, the timing of the lower low tides swings from daytime in the spring and summer to after dark in the fall and winter, and this change is clearly reflected in the TidbiT data.

Maximum vs. Minimum Daily Temperatures

Daviston Head High Maximum and Minimum Daily Temperatures Davison Head Mid Maximum and Minimum Daily TemperaturesBack to top

Graphs illustrating daily maximum and minimum temperatures differ slightly from those comparing Noon and Midnight.

Mean Maxima for High and Mid Tidal Heights

Davison Head Average Maximum Daily Temperature Point Caution Average Maximum Daily TemperatureBack to top

Mean maxima through the year are illustrated for the hottest and coolest sites, showing very similar seasonal patterns but substantial differences in the degree of heating. Davison Head (DH) was a south-facing site and Point Caution (PC) was north-facing. As expected, TidbiTs in the High zone consistently recorded hotter temperatures than in the Mid zone.

Mean Maxima for Hannah Heights

Hannah Heights Average Maximum Daily Temperature Back to top

A few sites (e.g. Hannah Heights,) had Mid zones that were as hot or slightly hotter than the adjacent High zone; these data reflected the Mid TidbiT's placement on a more-horizontal or a more-south-facing surface than the High one.


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