I remember being at the beach in Cape Cod and in the morning the water was so high above the ground that it nearly touched the road. But then in the afternoon the water seemed to lower a lot, so much that the sandy, beautiful beach had finally shown. Little did I know why this was happening...
It was the cause of Daily Tides, they happen twice a day. And there are two types: High Tide and Low Tide. Daily Tides are the glorious rise and fall of water coastlines that are the reason our sand castles at the beach get washed away...
Daily Tides are caused by the positioning of the Sun, Earth and Moon. There are two High Tides and two Low Tides a day. The first High Tide is caused by the gravitaional pull of the Moon and Sun. The second High Tide occurs 12 hours later and is caused by Centripital force. Centripital force is when something is being forced to stay put by the force of spinning but wanting to swing away. In this case the Earths is the one spinning and swinging the water (rotating fast) causing the water to want to fling of the Earth creating a tidle bulge. But the Earth's gravity makes it stay put. Low Tide occurs when the Moon and/or Sun is pulling on the opposite side of the Earth causing the other side to stay still. This is because there is no force pulling the water to it, so therefore it has no reason the bulge.
(curious.astro.cornell.edu)
Daily Tides occur at different times each day. Because the Moon is revolving around the Earth as the Earth revolves around the Sun, this causes Daily Tides to delay by 50 minutes each day. The Moon rotates and revolves at a much slower pace than the Earth, therefore it needs more time to catch up (50 minutes, slow poke!)
(science.howstuffworks.com)
Since Tides are the rise and fall of the Earth's water coastline there are two types of Monthly Tides. Spring Tide and Neap Tide. Spring Tide occurs when the Sun and Moon are lined up on either/opposite sides of the Earths, creating a tidle bulge which combines both the Sun and Moon's gravitational force. This makes the bulge much stronger, therefore there is a greater range between High and Low Tide. At this point the highest high tide and lowest low tide occur. Spring Tides happen only on a Full and New moon phase. There are also Neap Tides each month. Neap Tides happen when the Sun and Moon pull at a right angle, the gravitational pull is towards the Sun and Moon therefore it creates a very calm and still tide on the opposite side. This is when the lowest low tide and highest high tide occur. A Neap Tide happens on the 1st and 3rd quarter moon phase.
(dolio.lh.net)
In class this week we looked at many diagrams and read notes on the tides. We also spent a lesson looking at a globe and used a rubber-band to show the tidle bulge of each tide. Then we had a homework assignment where we had to explain what each tide was and what causes it. To help us with this we looked at the textbook and read the pages on the discription of each tide as well as looking at the diagrams in the textbook. By the end of the assignment I think we really understood the different tides. I know I did!!!
(mrnagribianko-ecozones.wikispaces.com)
(famousquotesabout.com)
Love Always,
Sharmila
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