Tides

TidesTides are the daily changes in the elevation of the

ocean surface. Tides are the daily rise and fall of the Earth’s waters on its coastlines.

Tides are caused by the interaction of the Earth, the moon and the sun.

A. Tides form from the gravitational attraction exerted upon the Earth by the moon.

B. Tidal Cycle-Is influenced by the sun and moon. When they are aligned together their forces are added.

Gravity is the force exerted by an object that pulls another object toward it. As the distance between two objects is greater the force becomes weaker.

Daily TidesTides happen regularly no matter what the wind is

doingTides 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 pointLow Tide-as the tide flows back toward the sea and

reaches its lowest point

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.

The Daily Tidal Cycle1. 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 surface2. Shape of the ocean floor/coastline3. Coriolis effect

May 24 Agenda1. Question of the day2. Finish tide notes3. Finish study guide4. Go over answers

Monthly Tide Cycle1. 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.

Spring tides1. 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!!!

Neap Tides1. 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.

http://upload.wikimedia.org/wikipedia/commons/0/03/Spingtide.jpg

http://upload.wikimedia.org/wikipedia/commons/c/c2/Neaptide.jpg

Tidal RangeTidal Range is the difference in height between high

and low tides.1. Spring Tides-Are the highest tidal range2. Neap Tides-Lowest tidal range

http://home.hiwaay.net/~krcool/Astro/moon/moontides/