Tides

Have you ever been to the ocean? The water moves up higher and down lower on the beach depending on the time of day. What causes the water to behave this way? Tides are the pattern of ocean water rising and falling due to the gravitational pull of the Moon and the rotation of the Earth. The oceans closest to and furthest away from the Moon experience high tides, where the water is at its highest point. Oceans are at their lowest point during low tides. As the Earth rotates on its axis, oceans experience low tides and high tides twice each day. The intertidal zone is the portion of the coastline that goes through periods of coverage and exposure due to the changing tides. Areas lower in the zone are more marine, or having to do with the ocean, since they are closer to the ocean. As you progress higher in the one toward the coastline, conditions are more terrestrial, or deal with dry land. This region is a complex environment with a variety of species adapted to the constantly changing habitat.

What do you think are the meanings of these words: intertidal zone, marine, and terrestrial?

There are several different zones present in the intertidal area: In the splash zone, species are adapted to withstand extended periods of exposure to the air and lack of ocean water. This region is above the high tide water line, so its water coverage is mostly sea spray and mist. The high zone is flooded during the highest of high tides but exposed during low tides. This habitat is largely terrestrial. The mid zone is covered and uncovered twice every day. Species that live here must survive turbulent waves and changing temperatures. The low zone is largely marine, as it is usually covered by water and only exposed during the lowest of low tides. This region is teeming with life because temperature and moisture are most consistent. There's a wide variety of life found in these zones. This life is all greatly impacted by the movement of the tides, and it is all powered by the rotation of the Earth and the Moon!

What are tides and gravitational pull?

What is unique about the intertidal coastline?

Which statement is true about the intertidal coastline?

Organisms that live in the splash zone must be adapted for

This is a model of the Earth, moon and sun. When

the Sun, Earth, and Moon are all in a straight line

this is called a spring tide.

The moon can also be on the opposite side of the

Earth and a spring tide will still occur. Spring tides

produce the greatest difference between high and low tide.

Draw an oval around Earth to illustrate a spring tide.

This is a model of the Earth, moon and sun. When the Sun, Earth, and Moon form a 90 degree angle this is called a neap tide.

The moon can also be on the opposite side of the Earth in this model and a neap tide will still occur. Neap tides produce the least difference between high and low tide.

Draw an oval around Earth to illustrate a neap tide.

What moon phases are present during the spring tide?

What moon phases are present during the neap tide?