Presentation on theme: "What are tides? The daily rise and fall of Earth’s waters at its coastline."— Presentation transcript:
What are tides? The daily rise and fall of Earth’s waters at its coastline.
What causes tides? Tides occur mainly due to the difference in the force of gravity between the moon, the sun, and different parts of Earth. (p. 676)
What causes tides? Because gravity tugs on nearby things more strongly than on distant things, the oceans closest to the Moon feel the greatest attraction to the Moon. This creates a bulge of water called a tidal bulge. http://static.howstuffworks.com/gif/moon-8.gif High Tide Side
What causes tides? The high tide on the far side of the Earth occurs because these most distant oceans feel the least attraction to the Moon. In essence, they are left behind as the Moon pulls the other parts of Earth toward itself with greater force. EX: http://static.howstuffworks.com/gif/moon-8.gif High Tide Side
What are spring tides? Twice a month - full and new moon - combined gravitational pull of sun and moon produces the greatest difference between the height of high and low tide Straight S
What are neap tides? First and third quarters of the moon – sun and moon pull at right angles to each other - tide with the least difference between high and low tide 90° Ninety N