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Daily Tides Tides happen regularly no matter what the wind is doing Tides occur in all bodies of water but are most noticeable in oceans. High Tide- as.

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Presentation on theme: "Daily Tides Tides happen regularly no matter what the wind is doing Tides occur in all bodies of water but are most noticeable in oceans. High Tide- as."— Presentation transcript:

1 Daily Tides Tides happen regularly no matter what the wind is doing Tides occur in all bodies of water but are most noticeable in oceans. High Tide- as the tide comes in toward the beach and reaches its highest point Low Tide-as the tide flows back toward the sea and reaches its lowest point

2 Daily Tides The moon gravity pulls on the water on the Earth’s Surface. The moon pulls on the water on the side closest to it more than it pulls on the center of the earth. This pull creates a Tidal bulge, a bulge of water on the side of the earth that is facing the moon. On the other side of the earth is a bulge of water that is pulled less strongly than the center of the earth. Where the tidal bulges are is where high tides occur. As the earth rotates different part of the earth's surface pass by these areas and experience the water level changes.

3 The Daily Tidal Cycle 1. All areas of the world oceans pass under the moon every 24 hours and 50 minutes. The cycle takes more than one day, each day the tides occur at different times 2. Every coastal area has at least one high tide and one low tide every day 3. Factors which influence the daily Tidal patterns are: 1.The earth’s surface 2.Shape of the ocean floor/coastline 3.Coriolis effect

4 Tidal Patterns determined by how many high and low tides in a 24 hour period. 1. Diurnal Tides-Include a single high tide and a single low tide each day. Example-Southeastern US along Gulf of Mexico 2. Semidiurnal Tides-Include two high tides and two low tides each day. Example-Atlantic Coast of US 3. Mixed Tides-Inequality of tide levels that has multiple high and low tides. Example- Pacific Coast of US

5 Tide patterns around the world

6 Monthly Tide Cycle 1. The sun’s gravity also effects the Earth, even though it is far away it is very large. The sun’s gravity pulls the earth’s water toward it. Sometimes the moon and sun pull the earth’s water in the same direction other times they pull in different directions.

7 Spring tides 1. Twice a month at the new moon and the full moon, the sun and moon are lined up. 2. These combined gravitational pulls cause the greatest tidal ranges. 3. Spring comes from the word to jump and does not refer to the season!!!

8 Neap Tides 1. At the first quarter (waxing) and third quarter (waning) moons, the sun and moon pull at right angles to each other. 2. Least tidal range due to the sun’s gravity pulling some of the water away from the tidal bulge facing the moon thus evening out the difference between low and high tide.

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11 Tidal Range Tidal Range is the difference in height between high and low tides. 1. Spring Tides-Are the highest tidal range 2. Neap Tides-Lowest tidal range http://home.h iwaay.net/~kr cool/Astro/mo on/moontides /

12 Monthly Tide Tables Scientists can fairly accurately predict tides at various locations. These are published as tide tables. Who is it important to, in order to know the times and heights of the tides?

13 Tidal Power The movements of water between high and low tide are a source of potential energy. The first large scale tidal power plant was built in 1967 on the Rance River in France. As the tide comes in gates open up into a basin. As the tide retreats the gates close, gravity pulls the water back through tunnels back to sea. The energy that travels through the tunnels generates electricity.

14 Table discussion The first part of putting turbines into Admiralty Islet in Seattle to use tides to convert tidal energy into energy for 710 homes is occurring. What impacts do you think this may have on the Ecology of the area. Do you think that the impacts are worth it? (in other words, which is the greater good) Explain why?

15 Shoreline Processes and Features Beach: A shoreline built of sediments that are locally available. The sediment is not stagnant, the waves are constantly moving it. The cycle of the beach is determined by the amount of sand and the surf condition. http://videos.howstuffworks.com/hsw/15732- erosion-on-the-move-beach-erosion-video.htm http://videos.howstuffworks.com/hsw/15732- erosion-on-the-move-beach-erosion-video.htmhttp://videos.howstuffworks.com/hsw/15732- erosion-on-the-move-beach-erosion-video.htmhttp://videos.howstuffworks.com/hsw/15732- erosion-on-the-move-beach-erosion-video.htm

16 Berm During the winter months, when weather is often bad, there are powerful waves with short periods between crests. Beach sand is moved away and the berm moves further inland. In summer sand is brought in and the beach builds up creating a berm that is closer to the shoreline

17 Forces acting on the shoreline How are each of the following impacting beaches? 1. Wave impact 2. Abrasion (grinding of rock fragments) 3. Wave refraction (bending of waves) - because of refraction wave energy is concentrated against the sides and ends of headlands and is weakened in bays

18 Long shore Transport Sands can be carried parallel to shore by long shore current. If a breakwater or jetty is inserted it breaks up this motion and a beach will form on the up-current side of the obstruction. Provincetown, Mass. Was formed by a longshore current

19 Erosional and Depositional Features Use the Earth Science book pg.463-465 to draw (or make a paper model) an example of each of the following Erosional and Depositional Features-make sure to label each type and whether it is erosional or depositional. The is an example over the paper towel dispenser. Wave cut Cliffs and Platforms Sea Arches Sea Stacks SpitsBarsTombolos Barrier Islands

20 Can you name these?


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