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NOTES What are the tides?. TURN TO PAGE page 434-438 IN YOUR SCIENCE BOOK. Learning Objective. Students will describe what causes and affects the tides. Key Terms. tide Spring Tides Neap Tides. Ocean Water Levels. The water level of the ocean rises and falls throughout the day.
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NOTESWhat are the tides? TURN TO PAGEpage 434-438 IN YOUR SCIENCE BOOK
Learning Objective • Students will describe what causes and affects the tides. By: Mr. D'Angelone
Key Terms • tide • Spring Tides • Neap Tides By: Mr. D'Angelone
Ocean Water Levels • The water level of the ocean rises and falls throughout the day. • Early in the day, ocean water rises and covers part of the beach. • Later in the day, the ocean level falls. • The beach is exposed. • These regular changes in ocean water levels are called tides. • A low water level is called low tide. • A high water level is called high tide. By: Mr. D'Angelone
Once a month we have a lower than normal Low tide (above) and a higher than normal high tide (below) in the same location. By: Mr. D'Angelone
Causes of Tides • The Earth's gravitational pull on the Moon keeps the Moon in orbit around us. • The Moon also pulls back on Earth and causes the tides. By: Mr. D'Angelone
Causes of Tides • The Sun's gravitational pull also affects Earth's tides, but because it is so far away from us, not as strongly. By: Mr. D'Angelone
Causes of Tides (2) • Earth's continents are slightly stretched by the pull of the Moon. • Earth's oceans, which move more freely, are stretched even more. • This stretching effect creates two bulges of water on Earth, one facing the Moon, the other directly opposite it. • These bulges are the high tides. • The bulging water also causes two areas with low tides between the high tides. • As the Earth turns on its axis, the tide levels rise and fall. By: Mr. D'Angelone
The Moon, along with the Sun, causes the tides. • Whether it is high tide or low tide depends mostly on where you are on Earth relative to the Moon. By: Mr. D'Angelone
Changing Tides • Some newspapers print tide tables. • A tide table tells the times at which high tide and low tide will occur. • If you look at a tide table, you will notice that it often shows two high tides and two low tides each day. • The tides change about every 6 hours and 15 minutes. By: Mr. D'Angelone
Tide Table A newspaper gives the times for high and low tide. By: Mr. D'Angelone
Spring Tide • A new moon phase and a full moon phase causes a major change in tides. • This causes the Earth, moon, and sun to align which causes a very high tide called a Spring Tide. (2 spring tides per month) By: Mr. D'Angelone
Neap Tide • A 1st quarter and a third quarter moon phase causes a major change in tides. • This causes the Earth and moon to be at a right angle to each other which causes a extremely low tide called a Neap Tide. (2 spring tides per month) By: Mr. D'Angelone
Checking Concepts • What is the the two highest tides per month called? • How often each day do tides occur? • What is the the lowest tide called? • How many really low tides do we have per month? • What has to be aligned to have a very, very high tide? By: Mr. D'Angelone
Answers • An spring tide • Twice • A neap tide • two • the Earth, moon, sun By: Mr. D'Angelone