IALT: Explain the phenomenon of tides (why they occur) and identify the different types of tides. IASW: I can… 1. Create a PowerPoint explaining why tides happen and give a brief explanation of each type of tide (in my own words). 2. Create a visual diagram showing what the earth looks like during high and low tide.
What are Tides? Tides are the annual rise and fall of the ocean. These are caused due to the gravity of the moon, lesser extent of the Sun and the rotation of the Earth.
Tides in Detail The Sun and Moon pull on the Earth, the water and even us! But gravitational pull depends on the distance and mass. For example, you have very little mass and you're very close to the Earth, so the Sun and Moon can't just yank you off the planet. The Sun is massive, but it is an average of 150 million km from Earth, compared with about 384,400 km from here to the Moon, and since the Moon is nearly 400 times closer to our planet, its influence on our oceans is twice as strong as the Sun's.
The key to tides is the varying strength of the Moon's alternating pull on different parts of Earth. The Moon pulls most on the water nearest to it, creating a high tide bulge of water. On the other side of the planet, about 1,2760 km away, the Moon's pull is much weaker and the water is left to form another high tide bulge. Low tides are found halfway between the high tides. The rotating Earth carries us through these regions of high and low water.
Neap Tide When the Sun and Moon form a right angle or when we see a half moon, their gravitational pulls fight each other and we notice a smaller difference between high and low tides. These are called neap tides.
Spring Tide When the Moon, Earth, and Sun fall in a straight line, which is called syzygy ( siz-eh-gee ), we notice the greatest difference between high and low water levels. These spring tides occur twice each month, during the full and new Moon. If the Moon is at the revolution, the closest it approaches Earth in its orbit, the tides are especially high and low.
High Tide A high tide is when the water comes right up to the beach. So say there is not much sand left to walk on. High tides occur once every 6 hours. When the moon pulls the Earth towards it, it creates a bulge. When this bulge is big, then there is a high tide. high tide
Low Tide A low tide occurs every 6 hours, just like the high tide. It’s when the sea goes out and there are lots of sea stars and seaweed on the sand. (There will be more seaweed after a storm.) When the moon pulls the Earth towards it, it creates a bulge. When this bulge is small, then there is a low tide. low tide