NOAA Tides Worksheet
NOAA "Understanding Tides" Worksheet
Go to: http://www.montereyinstitute.org/noaa/
1: What are tides?
The regular, alternating rise and fall of the sea level.
2: What causes tides? Explain in detail (show diagram)
The gravitational forces of the moon and sun, and the rotation of the Earth tug on seawater and cause it to form into two enormous bulges one either side of the planet, one facing the moon and the other in the opposite direction. These form the basis for the tides.- See pictures above
3: Where do tides occur?
They occur in the ocean. 4: Explain- High and low tides (difference)
High tide is where the sea level floods to its highest level, and low tide is where it ebbs to its lowest level.
5: Which object exerts the most force on the tidal bulge? Why?
The moon exerts the most force because even though it is much smaller, it is also very close to the earth
6: What happens when the sun and moon align? What happens when they are perpendicular to each other?
When they are aligned, their gravity combines to form the largest tides, spring tides, and when they are perpendicular, they form moderate neap tides.
7: What are some of the other factors that affect tides?
Seafloor topography, river discharge and wind and weather conditions
8: What are the zones of the intertidal zone?
The spray zone, the upper intertidal zone, the mid intertidal zone, and the low intertidal zone.
9: What are some of the challenges for the critters of the intertidal zone? Explain.
They have to live without water for periods of hours to sometimes weeks, and endure temperature extremes, sunlight.
10: How do the intertidal organisms cope with the harsh environment?
Often organisms develop tough outsides to hold water and prevent loss of water, scrunch together to prevent exposure to sunlight, secrete mucus to use when outside water, close up their shells tightly, hide underneath rocks or in the sand, and/or cement themselves to rocks, sand or each other to protect against waves.
11: What are some of the adaptations that help organisms cope with wave action?
Strong skeletons, hard shells, grippers, hard skin, thick shells, firm roots, flexible stems, sturdy bodies, strong muscles, etc.
Go to: http://www.montereyinstitute.org/noaa/
1: What are tides?
The regular, alternating rise and fall of the sea level.
2: What causes tides? Explain in detail (show diagram)
The gravitational forces of the moon and sun, and the rotation of the Earth tug on seawater and cause it to form into two enormous bulges one either side of the planet, one facing the moon and the other in the opposite direction. These form the basis for the tides.- See pictures above
3: Where do tides occur?
They occur in the ocean. 4: Explain- High and low tides (difference)
High tide is where the sea level floods to its highest level, and low tide is where it ebbs to its lowest level.
5: Which object exerts the most force on the tidal bulge? Why?
The moon exerts the most force because even though it is much smaller, it is also very close to the earth
6: What happens when the sun and moon align? What happens when they are perpendicular to each other?
When they are aligned, their gravity combines to form the largest tides, spring tides, and when they are perpendicular, they form moderate neap tides.
7: What are some of the other factors that affect tides?
Seafloor topography, river discharge and wind and weather conditions
8: What are the zones of the intertidal zone?
The spray zone, the upper intertidal zone, the mid intertidal zone, and the low intertidal zone.
9: What are some of the challenges for the critters of the intertidal zone? Explain.
They have to live without water for periods of hours to sometimes weeks, and endure temperature extremes, sunlight.
10: How do the intertidal organisms cope with the harsh environment?
Often organisms develop tough outsides to hold water and prevent loss of water, scrunch together to prevent exposure to sunlight, secrete mucus to use when outside water, close up their shells tightly, hide underneath rocks or in the sand, and/or cement themselves to rocks, sand or each other to protect against waves.
11: What are some of the adaptations that help organisms cope with wave action?
Strong skeletons, hard shells, grippers, hard skin, thick shells, firm roots, flexible stems, sturdy bodies, strong muscles, etc.
Do: Predicting the Tides
Answer the questions with the animations- post on your website with diagrams and descriptions
Questions
What is the global impact of tides? Explain.
~ The global impact of tides, when tide currents bounce off sea-floor ridges and shells. The disturbing turbulence mixes ocean water, redistributing heat & nutrients, and helps regulate the climate.
What are some of the challenges on coastal areas because of tides?
~ Some of the challenges on coastal areas cause problems for coastal residents, designers of faculties as, ports, bridges, and off shore oil plat-forms.
Explain how electricity can be generated by currents and tidal power.
~ Electricity can be generated by currents and tidal power, by using off-shore turbulence which function like under-water wind-mills.
Answer the questions with the animations- post on your website with diagrams and descriptions
Questions
- How much time passes between one high tide and the next?
The tides are caused mainly by the gravitational attraction between the moon and the earth, so the spacing between tides will depend on the length of the lunar day. Since the lunar day is 24 hours and 50 minutes long and the earth rotates through two tidal bulges in that time, high tides will be spaced 12 hours and 25 minutes apart. - How much time passes between low tide and the next high tide?
High tides are 12 hours and 25 minutes apart and are separated by a low tide. So low tide must come 6 hours and 12.5 minutes after one high tide and before the next. - Explain how spring and neap tides are created.
The tides are created by the pull of the moon and the sun. When those bodies are aligned with one another, their gravitational forces act in the same direction and reinforce one another, creating the maximum possible tidal bulges, called the spring tides. When the sun and moon are at 90o from one another, relative to Earth, their tidal forces are also pulling in different directions, so the neap tides are minimized. - How many spring and neap tides occur each month? Why?
There are 2 spring and 2 neap tides each month. The moon rotates around the earth once in a month, so in that time it will be aligned with the sun twice, and at 90o to the sun twice. - Why does the distance from the earth to the moon or the sun affect the tides?
The tide generating force depends on the mass of an object and its distance. As the distance between the earth and the moon or sun changes, the tidal force each produces will vary. - When will lunar tides be higher, at perigee or apogee? How often does each occur?
The lunar tides will be highest when the moon is closest to the earth, a point in the moon’s orbit that is called perigee. It takes the moon a month to complete an orbit, so perigee will happen about once a month. - When will solar tides be higher, at perihelion or aphelion? How often does each occur?
The solar tides will be highest when the sun is closest to the earth, a point in the earth’s orbit that is called perihelion. It takes the earth a year to complete an orbit around the sun, so perihelion will happen once a year. - Describe the conditions that made a safe trip possible.
Tidal ranges are greatest (higher high and lower lows) when the gravitational forces of the sun and moon are at their maximum and working in the same direction. This will happen when the sun is at its closest point to earth (during perihelion in early January) and so is the moon (at perigee), and when the two are in a line with Earth (during the full and new moons). - Your sister ship will have to wait to make the same attempt until you unload your cargo and clear the dock. If you leave on a high tide that crests at noon, when should your fellow captain make his move?
If the dock becomes clear at noon, the subsequent low tide will follow 6 hours and 12.5 minutes later. So the other captain should try to pass under the bridge just after 6 p.m.
- Do: Life in the Intertidal Zone
- How does the abundance and diversity of life change across the various intertidal zones?
Life is very abundant and very diverse in the lower intertidal, and becomes less diverse towards the high intertidal. Both diversity and abundance are lowest in the spray zone. - Describe how the physical stresses on life vary from the top of the intertidal zone to the bottom.
At the top of the intertidal zone, organisms spend more time exposed than underwater, so they will have to cope with desiccation and large temperature swings. Those pressures will be less important lower in the intertidal zone because of the protection provided by greater time underwater. But plants and animals there are at, or just below, the surf zone, so they will be pounded by waves. - How are these stresses reflected in the types of animals that inhabit the intertidal subzones?
Many of the creatures that live in the highest intertidal zones either have the ability to close themselves up into their shells as a shelter against drying out, or are mobile enough to take cover. In the lower parts of the intertidal zone, many animals and plants have a means of attaching themselves in place and are either very sturdy or very flexible to stand up to wave energy. - Living conditions in the intertidal zone are difficult, yet most of it is abundantly populated. What are some of the benefits of intertidal living? A. The harsh conditions in the intertidal zone cut down on competition for food and for space by excluding many animals. And the shallow water transmits the sunlight for bottom-dwelling plants’ need for photosynthesis.
- Answer the questions with the animations- post on your website with diagrams and descriptions
What is the global impact of tides? Explain.
~ The global impact of tides, when tide currents bounce off sea-floor ridges and shells. The disturbing turbulence mixes ocean water, redistributing heat & nutrients, and helps regulate the climate.
What are some of the challenges on coastal areas because of tides?
~ Some of the challenges on coastal areas cause problems for coastal residents, designers of faculties as, ports, bridges, and off shore oil plat-forms.
Explain how electricity can be generated by currents and tidal power.
~ Electricity can be generated by currents and tidal power, by using off-shore turbulence which function like under-water wind-mills.