Tides Periodic rising and falling of ocean waters caused by the gravitational pull of the sun, moon & Earth. Also affected by: Shape and depth of ocean floor Latitude (greater pull at the equator) Volume of water

Sun, Moon or Earth? Which has the greatest affect on tides? The Moon! Even though the sun is larger, the moon is closer so it has more “pull”

Spring Tides Tide of max range (high, high tides and low, low tides) Occur when Earth, sun & moon are aligned Occur during full and new moons

Neap Tides Tide of min range (high and low tides are weak) Gravitational forces of the moon & sun are at a right angle with the Earth Occur at quarter moons

The Earth and the Moon revolve around each other and rotate on their axes Earth’s rotation = 24 hours Moon’s rotation = 24 hours and 50 minutes Tides occur 50 minutes later every day because of this rotation time difference

How Stuff Works: Tides

Bay of Fundy *Video Clip

Frequency of Tides Semi-diurnal Mixed Diurnal 2 equal high and low tides per day East coast of United States Mixed 2 highs and 2 lows of unequal range West coast of US & west coast of FL Diurnal 1 high and 1 low tide per day Parts of Gulf of Mexico NOT FLORIDA!

Tides https://tidesandcurrents.noaa.gov/tide_predictions.html?type=Tide+Predictions&searchfor=South+Padre+Island

Questions for each tide table: How many high and low tides did this place experience on the first day shown on the chart? B. What type of tidal pattern does this place have? C. What are the tidal heights (low & high) on the 1st day listed? D. Do the tides on the first day listed appear similar to the tides listed on the second day? Yes or No. If no, what could be the cause of the change?

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How do Tides Influence Marine Organisms