Science Lesson 28 Tides

online content How might scientists use a CTD instrument? (site 2)

A CTD instrument can determine conductivity, temperature and pressure in the ocean. Scientists can use the information to monitor how many and what different types of organisms live in the ocean.

What is a tidal bulge?

A bulge in the oceans on the side of the Earth closest to and farthest away from the moon due to gravity.

On what type of coast would a tidal bore most likely occur?

A coast with river channels, narrow bays, and inlets.

On what kind of coast line would you predict the largest tidal ranges to occur?

A coastal area that sits on a large body of water and has a long, narrow inlet are an area where a river flows into the ocean.

What is a neap tide and when would a neap tide occur?

A neap tide is the lowest tide (when there is the least difference between high and low tides). It happens when the Earth, Sun, and moon create a triangle during the first and third quarters of the moon.

What is a spring tide and when would a spring tide occur?

A spring tide is the highest tide (when the greatest difference between the high and low tides). This happens during the new and full moons.

c. Image C

A tide monitor was placed in the water and recorded data for several days before being broken by a curious seal. A graph was made of the data collected up to the time that the monitor was broken, indicated by the blue arrow. Which image represents the positions of the monitor, the Moon and the Sun at the time the monitor was broken? (Note: In each illustration the monitor is represented by a human figure.) a. Image A b. Image B c. Image C d. Image D

spring tide

A tide with the greatest differences between high and low tide that occurs when the sun and the moon are aligned with Earth at the new moon and full moon.

neap tide

A tide with the least difference between low and high tide that occurs when the sun and moon pull at right angle to each other at the first and third quarters of the moon. *A neap tide has a smaller than normal tidal range.

b. neap low tide

Based on the diagram above, what type of tide will the observer experience? a. neap high tide b. neap low tide c. spring high tide d. spring low tide

•Describe four different types of tide

High tide, Low tide, Neap tide and Spring tide.

c. above the image

In the diagram above, the observer is experiencing a spring low tide. What is the most likely position of the Sun? a. to the left of the image b. to the right of the image c. above the image d, all positions are equally likely

online content In what ways might tidal waters be different from other waters? (site 1)

Rivers that flow into the ocean, salt marshes and tidal mouths are affected by the moon, sun, and Earth just like the ocean tides but they don't affect ponds, lakes, and waters of that nature.

tidal range

The difference in levels of ocean water at high tide and low tide. *The tourist was surprised to find that the huge beach had disappeared under the water because of the large tidal range of the area.

tidal

The periodic rise and fall of the water level in the oceans and other large bodies of water. *At low tide the waves washed out, leaving stranded shells on the beach.

online content How do the tides affect organisms that live in tidal waters? (site 1)

The tides are very important to the sea creatures. Some of them base their feeding and reproductive schedules on the tides.

How many days pass between the minimum and the maximum of the tidal range in any given area? Explain your answer

There are about 14 days between the minimum and maximum tidal range. This is due to tides being created mostly by the moon. There are four cycles that last about seven days each that the moon goes through every month. The highest tides happen during the new moon and full moon phases. The lowest tides happen during the first and third quarter phases.

•Explain tides and their relationship with the Earth, sun, and moon

Tides are the pattern of the ocean rising and falling and it's due to the gravitational pull by the moon.

Explain how the positions of the Earth, moon, and sun affect the tides.

Write in your own words. During spring tides, the gravity of the sun and moon pull on the Earth either from the same direction or from opposite directions, producing higher tidal ranges. During neap tides, the sun and moon are at right angles with respect to the Earth. This lessens their pull on Earth, producing lower tidal ranges.

•Analyze the relationship between tides and coastal land

You're going to have tidal bores if there's a narrow strip of land where the water rushes through from the tide so you're going to get an extreme variation between high tide and low tide.

Some organisms will base what schedules on tidal movements? a. Reproduction and feeding b. Feeding and sleeping c. Sleeping and reproduction d. Recreation and predation

a. Reproduction and feeding

How often do high tides occur? a. about twice a day b. about twice a week c. about twice a month d. about twice a year

a. about twice a day

When do the greatest tidal ranges occur? a. spring tides b. neap tides c. high tides d. low tides

a. spring tides

What kind of instruments do students use as part of the HIGH TIDE to study tidewater? a. A NOAA b. A CTD instrument c. A gyroscope d. A satellite

b. A CTD instrument

Which statement explains why the moon's gravity is able to create high and low tides? a. the moon is revolving more quickly than the Earth is rotating. b. The moon is revolving more slowly than the Earth is rotating. c. Some parts of the Earth never face directly on the sun and moon. d. The moon is revolving at the same speed that the Earth is rotating.

b. The moon is revolving more slowly than the Earth is rotating.

How often do neap tides occur? a. about once a month b. about twice a month c. about once a year d. about twice a year

b. about twice a month

From what is known about spring and neap tides, you can conclude that a. the sun's gravity exerts the most power when the moon is on the opposite side of the Earth from the sun. b. the height of high tides varies with the phases of the moon. c. spring tides and neap tides affect the phases of the moon. d. the moon revolves around the Earth every 14 days.

b. the height of high tides varies with the phases of the moon.

The Bay of Fundy has the greatest tidal ranges on Earth. What can you infer about the Bay of Fundy? a. It faces the moon more often than other places on Earth. b. It has many rocky beaches. c. It is a long, narrow inlet. d. Its tides cannot be predicted accurately.

c. It is a long, narrow inlet.

Which statement describes what is happening at high tide? a. The moon is revolving more quickly that the Earth is rotating. b. The moon's gravity is dragging water away from the equator. c. The moon's gravity is pulling ocean water into a bulge. d. The sun's gravity pulls with more force than the moon's gravity.

c. The moon's gravity is pulling ocean water into a bulge.

Tides affect the levels of _____ in tidal waters. a. temperature b. salinity c. nutrients d. all of the above

d. all of the above

An unusually high tide is called a ______ tide. a. major b. tall c. neap d. spring

d. spring

the force that pulls the tides

gravity

bulge that takes place on parts of Earth facing or opposite the moon

high tide

forms when water is drawn away from the area between high tides

low tide

The most important force that creates tides is the gravity of the _______.

moon

tides that occur during the first and third quarters of the moon.

neap tide

tides that occur during the new and full moons

spring tides

A narrow inlet of land along a coast is where you might see a ___________. This causes a very sudden rise in the tide.

tidal bore

The difference between levels of ocean water at high tide and low tide is called a(n) _______.

tidal range

the periodic daily rise and fall of ocean water

tides

Neap, spring, high, and low are all types of ______.

tides.

Tides Objectives

•Explain tides and their relationship with the Earth, sun, and moon •Describe four different types of tide •Analyze the relationship between tides and coastal land

The Lure of the Moon

•High tide and low tide -the waves rise and fall because the Earth rotates so much more quickly than the moon revolves around it. •Battle of the bulge -water bulges on the opposite side of the Earth to the moon due to centrifugal forces. -water bulges of the side of the Earth facing the moon due to gravity. •Timing of the tides -it takes more than 12 hours if the Earth and moon revolved around the Earth at the same speed we would have no tides.

Tides and Topography

•Tidal Bores -tides can be affected by land

Tidal Variations

•Tidal range -the difference between a low tide and a high tide. •Spring tides -Are REALLY high. Occurs when the Sun, moon and the Earth all line up. *The gravitational pull on the moon combines with the Sun's pull and puts an additional pull on the ocean waters. •Neap tides -Are SUPER low tides. This happens because the moon and Sun are at right angles to the Earth. They're fighting for the pull of the water.