Waves Name: _________________

When wind blows over the ocean's surface, it creates waves. Their size depends on how far, how fast and how long the wind blows. A brief, gently breeze forms patches of tiny ripples on the surface; strong, steady winds over long distances create large waves. But even when you feel no wind at all, you may encounter large swells created by distant storms. In the open sea, waves make floating boats bob up and down instead of pushing them along. This is because the waves travel through water - they do not take the water with them. As a wave arrives it lifts water particles. These travel forward, then down and back so that each particle completes a circle. When one water particle bangs into its neighbouring particle, energy transfers to that neighbouring particle. Circling movements of particles near the surface set off smaller circling movements below them.

 

 

 

Parts of a Wave

• A water wave has two main parts – a high point called the crest, and a low point called the trough.

• The distance between one crest and the next (or between one trough and the next) is called the wavelength.

• The distance between the crest and trough of a wave is the wave height. • When many waves are connected together, one after the other, it is called a wave

train.

In the following figure, identify the parts indicated by letter. Write the correct name next to the letter.

1. A ______________ D ______________ F _______________

B ______________ E ______________ G ______________ C ______________

2. Use a ruler to measure each of the following on the diagram above: a) wave height ______ mm b) wave length ______ mm

3. Are all the waves of this train the same size? Yes or No 4. Take a guess – Must all the waves of a given wave train be the same size? Yes or No

Why? __________________________________________________________ _______________________________________________________________

5. A group of connected waves is called a:

a) crest b) wave length c) wave train d) wave height

6. A wave height is the distance between: a) two adjacent crests b) two adjacent troughs c) a crest and a trough d) both a and b

7. A wavelength is the distance beteen:

a) two adjacent crests b) two adjacent troughs c) a crest and a trough d) both a and b

8. Most waves are caused by:

a) tides b) earthquakes c) wind d) volcanoes

9. Wave size is affected by: a) wind speed b) time wind lasts c) distance wind travels d) all the above

Oceanography

• Oceanography is the scientific study of ___________

• Oceans make up over _____ of the Earth’s surface

• An ocean must be large and have features which set it apart from other oceans (___________, water masses, submarine ___________, land masses)

Five Major Oceans

1. __________Ocean (largest ocean, over 30% of Earth’s surface)

2. __________Ocean (2nd largest)

3. __________Ocean (3rd largest, mostly in Southern Hemisphere)

4. __________Ocean (north pole, smallest ocean)

5. __________Ocean (south pole)

• The average depth of the oceans is approximately ____ greater than the average elevation of the continents

• Mt. Everest, the highest peak on land would completely ___________ in the Mariana Trench, the ___________ place in the ocean

Salinity in the Oceans

The salt that is in the ocean is actually made up of a number of different chemicals that are dissolved in the water, and are called "ions". Six of these ions make up almost all (99.36%) of the ions in sea water. These ions are: Chloride, sodium, sulfate, magnesium, calcium and potassium. You'll notice that the two most common ions, sodium and chloride make up common table salt (NaCl) when put together. But where did these ions come from? As the rivers move to the ocean, they dissolve the rocks that they pass over. Although this is a slow process, the rivers have been flowing for a very long time!. The dissolved ions in the water make their way to the ocean. When water evaporates from the ocean and falls on land as rain, the ions are left behind in the ocean. Does this mean that the ocean is getting saltier and saltier? No! It is believed that the oceans of the world are about as salty today as they were 1.5 billion years ago. The ions are removed from the sea in a variety of ways. Calcium is removed by animals that deposit it in their shells. An arm of a sea can become isolated, and through evaporation, leave all of its salt behind (an examples are the salt flats in Utah). The most important way that the ions are removed from seawater is that ions can become "trapped" onto fine particles that then drift to the bottom of the ocean to become sediment. They are then not returned or redissolved into the seawater.

The salinity of the oceans varies according to depth and location. The highest salinity values are found in surface waters near the equator, where evaporation is high and precipitation is low. The lowest salinity values are found in surface waters towards the poles, where evaporation is low and freshwater inputs from melting ice and precipitation are high. Deep ocean waters are much less variable in salinity, since they are not subject to evaporation or direct freshwater inputs.

Questions:

1. a) List the six chemicals most commonly found in ocean water.

1. ________________

2. ________________

3. ________________

4. ________________

5. ________________

6. ________________

b) Which two chemicals are the most common, and which common substance do they combine to form?

________________ + ________________ = ________________

2. Describe where the salt in the oceans come from.

3. Describe three different ways dissolved chemicals are removed from ocean water.

1. ___________________________________________________________

2. ___________________________________________________________

3. ___________________________________________________________

4. Which parts of the ocean tend to be the saltiest? Why?

5. Which parts of the ocean contain the least amount of salt? Why?

6. Why does the salinity not vary as much in deep ocean water?

SALINITY OF SEA WATER

• Salinity is a measure of the ___________ solids in sea water (the main solid is common salt: sodium chloride)

• On average 1000 grams of sea water contain 35 grams of __________ and is written as 35‰ (note that 35‰ is also 3.5%)

Areas of Low Salinity

1. Areas where fresh water enters the oceans (mouths of ___________)

2. Areas of heavy ___________ (e.g., equator)

3. Areas where ___________ enter the oceans

Areas of high salinity

1. Hot, ____ climates (oceans lose water by evaporation leaving the salts behind). The Mediterranean Sea and the Red Sea can be as high as 40‰

2. In _________ waters near sea ice (when sea water freezes, only freshwater ice forms thus saltier water is left behind)

Why Salinity is Important

• We can find salinity by ___________ and measuring the amount of salt left behind

• A quicker method is to measure the electrical _____________ of the water (the greater the quantity of dissolves salts, the more easily current flows)

• Salinity is important in identifying water _________: a body of water that has certain properties due to conditions at its place of origin

Composition of Sea Water

• The ___________ shown are the same for all seawater anywhere in the world.

• The ___________ amounts of the different dissolved ions do not change even though the salinity does change.

Ocean Currents Name: ___________

The water in the world’s oceans travels in well-defined circular patterns called currents. These currents are similar to river flows, and are caused by:

• global winds pushing water in the direction of the wind • spinning of the earth (causes currents to move at an angle) • continents causing currents to bend

North of the equator, currents bend to the right. South of the equator, currents bend to the left. This is called the Coriolis Effect. Energy from the sun also causes currents to flow. Water near the equator is heated more than water at middle latitudes; as a result, surface water flows away from the equator towards the poles. Where two currents meet, the colder, more dense water sinks and pushes warmer, less dense water up to the surface. The Gulf Stream runs along the east coast of the United States and Canada. It is one of the strongest currents known. The Gulf Stream is a warm, salty current up to 60 km wide, 800 m deep and in some places it may travel more than 100 km in a day. The importance of currents can be seen when they change. On the west coast of South America, the Humboldt (Peru) Current normally brings cold water to the surface. With it come minerals and other nutrients that feed huge schools of fish. During an El Niño event, trade winds diminish and warm water flows down western South America. This stops nutrient-rich cold water from rising up and cause plankton and fisheries to fail.

Use the Ocean Currents Map on the previous page to answer the following questions: 1. Cross out the incorrect terms in the following statements.

a) North of the equator, ocean currents move in a (clockwise/counterclockwise) direction. b) South of the equator, ocean currents move in a (clockwise/counterclockwise) direction. c) The Gulf Stream starts in the Gulf of Mexico where the water is (warm/cold). d) The Gulf Stream flows (northeast/southwest) toward Europe. e) It flows towards the coast of (Japan/England).

2. Identify the correct current in the following statements.

a) If you tossed a bottle into the (Pacific/Atlantic) Ocean, it could be washed up on the coast of Japan. b) The bottle would be carried by the (Gulf Stream/Japan) Current. c) If you tossed a bottle into the Atlantic Ocean, it could be washed up on the coast of

(England/Hawaii). d) It would be carried by the (Gulf Stream/California) current. e) The ocean currents near Brazil are (warm/cold) because they carry water coming from the

(equator/poles).

3. Imagine you are a ship’s captain.

a) If you were sailing a ship to England from Canada, you would (seek out/avoid) the Gulf Stream because… _________________________________ ________________

b) If you were sailing a ship from England to Canada, you would (seek out/avoid) the Gulf Stream because… _________________________________ ________________

4. Complete each statement using a term or terms from the list below. Write your answers in the space provided.

Continent cold currents equator

Warm currents ocean currents global winds

Move at an angle poles clockwise

1. The general movement of the ocean waters are called ___________________. 2. The chief cause of ocean currents is the ___________________. 3. The turning of the earth makes the currents ___________________. 4. An ocean current turns around when it comes near a ___________________. 5. In Canada, the ocean currents move in a ___________________ direction. 6. Ocean currents are classified as ___________________ and

___________________. 7. Warm currents start near the ___________________. 8. Cold currents start near the ___________________.

TEMPERATURE OF OCEAN WATER

• Oceans don’t ___________ readily

• Almost all energy comes from the _____ (heat and light)

• Most solar ___________ is absorbed in the top few meters only, thus ocean temperature ___________ quickly with depth

Ocean Temperature Zones: Three Layers

1. Mixed Layer:

• surface layer where ______ and ________ mix heat evenly throughout the zone

• warm-water layer (____% of oceans volume) • Only place where light is present in enough quantity for ___________ to

grow • High latitudes near the equator: this layer is about ______ meters deep

and 30°C all year • Middle latitudes this layer can be _____ meter deep and have large

__________ changes (10° change between summer and winter) • Near_________ this layer may be -2° all year

2. Thermocline:

• layer __________ the mixed layer • temperature rapidly _________to

about 5°C • This layer goes to at least 1000

meters deep 3. Deep Water:

• Approx _____ • Depth is around 1000 – 4000 meters • In the polar areas the oceans are cold throughout and since cold water is

_________ it sinks and travels away from the polar regions and thus is found underneath other ocean water at almost all latitudes.

LIFE IN THE SEA

• Most in ___________ Layer (sunlight can penetrate)

Phytoplankton:

• microscopic _________

• basic _______ source for ocean life (almost all life in the ocean depend on them)

• able to produce their own food (_______________)

• Phytoplankton are eaten by ___________ whom are eaten by everything from tiny fish to giant whale

Oxygen

• Almost all living things need oxygen to convert their food into ___________

• Oxygen comes from either the ________ mixing with ocean water or it is given off by ___________ living in the water

• Therefore, the ___________ layer has the most oxygen

• The deep ocean accumulates _______________ since no plants are found here to consume carbon dioxide (no photosynthesis)

Ocean Floor Vents (eg. Black Smokers)

• Some ___________ can live here (2.5 km below the oceans surface)

• They don’t require sunlight for ___________ or phytoplankton for _________

• Certain ___________ thrive on the hydrogen sulfide produced here and they become food for larvae and other organisms (barnacles, giant clams, white crabs, giant tube worms) living near the vents

Heating the Oceans and Ocean Life Worksheet (pg. 314-317)

1. The ocean is heated from the surface down by ___________ and most of the energy is absorbed in the first few meters.

2. The surface layer is called the _______________ because wind and waves transfer heat uniformly through this layer.

3. The surface varies in thickness from ______ meters at the equator to as deep as _______ meters at other latitudes.

4. Below the surface layer the water temperature changes relatively fast in a layer called the __________________

5. Very cold water from the polar regions moves slowly along the bottom to the deepest parts of the ocean in a deep current called __________________.

6. The ocean may be divided into ______________ vertical temperature zones.

7. The largest temperature changes in the surface layer of the world’s oceans occur in the __________________ latitudes.

8. Explain how seasonal changes affect the “mixed layer” of the oceans. Give an example of the size of temperature change which can occur in the mixed layer. (see topic 9 of chapter 17)

9. How warm is the mixed layer at: a) The equator? _______________ b) the North pole? _______________

10. How cold is the bottom of the “thermocline”? ______________

11. How does the water temperature change from the bottom of the “thermocline” to an ocean’s floor?

12. Why is the bottom of the Mediterranean Sea the warmest bottom water in the world, at 12°C?

13. In the surface layer, there is an important group of floating microscopic plants called ______________________________

14. The microscopic plants are eaten by microscopic floating animals called ___________

15. Why are these microscopic animals so important to the food chain in the oceans?

16. Why do marine organisms need oxygen?

17. Explain why few fish are found at depths lower than the first few hundred meters of the oceans?

18. _____________________ accumulates in the deep ocean waters because there are no plants at great depths.

19. Hot springs that have been found on the floor of the Pacific Ocean are known as _____________________________________

20. What kinds of organisms are found living on the ocean floor new hot springs? How do these organisms survive?

OCEAN FLOOR

The ocean floor is divided into two major regions

1. Continental ___________ (Continental shelf, continental slope, continental rise)

2. Ocean ___________ (Abyssal plains, Abyssal hills, Seamounts, Guyots, Coral Atolls, Trenches, Mid-Ocean Ridges, Fracture Zones)

Continental Margins:

Continental Shelf

• Part of the __________that is underwater (about 130 m)

• Extends from the __________ to the shelf edge

• An active continental margin: very narrow and bordered by an ocean _________, has coastal mountains along the shoreline (___________ zone)

• A passive continental margin: __________ shelf some can be 300km wide, bordered by a coastal plain (seafloor spreading)

Continental Slope

• Begins at the shelf edge where water depth starts to ___________ rapidly (it slopes down toward the deep ocean)

• Changes from ___________ crust to ___________ crust

• About 200km wide and 3km deep and has many gullies and small valleys

• Undersea landslides = ___________ currents (powerful current of mud and sand with water, causing erosion)

• Gigantic gully = submarine ___________

Continental Rise

—Gently sloping region between the continental _________ and the ocean _________

—Deposition of sediment several ___________ thick

—Only found at ___________ continental margins

—Can be up to 1000km wide with a very ___________ slope

Ocean Basins:

Abyssal Plains

• 3000-6000m deep

• They are so _________ that they are the flattest areas on the Earth’s surface

• Made of sediments from the ___________ carried by turbidity currents

Abyssal Hills:

• small ___________ hills, 1-10 km wide and a few hundred meters high

Seamounts:

• cone-shaped mountain peaks, ___________ in origin and seem to be related to ___________ boundary activity (and/or hot spots)

Guyots:

• look like seamounts with their ___________ sliced off (flat-topped seamounts), tops were originally above sea level but removed by wave action (___________)

Atolls:

• ring shaped ___________ islands

• Begins to form when a coral ___________ forms around a volcanic island

• as the seafloor around the island ___________, the coral sinks with it but new corals grow on top of the old coral

• Eventually the volcanic mountain is completely ___________ sea level but the circular reef (atoll) is left with a central lagoon.

Trench:

• long narrow steep-sided troughs that runs ___________to either a continental margin or chains of volcanic islands (almost all in Pacific Ocean)

• Areas where crust ___________ under another plate

Mid-Ocean Ridges:

• found at ___________ plate boundaries, area where new oceanic crust forms as two lithospheric plates move ___________

• Huge undersea ___________ranges

The Ocean Floor Name: __________ The ocean floor has an average depth of 4 km, or 13000 ft - but a lot of the ocean is deeper or shallower than that. In fact, the sea floor varies quite a bit in depth, with topographic features analogous to mountains and valleys on land. Around most continents are shallow seas that cover gently sloping areas called continental shelves. These reach depths of about 200 m. The continental shelves end at the steeper continental slopes, which lead down to the deepest parts of the ocean. Beyond the continental slope is the abyss, where the depth falls to somewhere between 3 and 5 km. The abyss consists of flat regions called abyssal plains, which are interrupted with hills and mountains called seamounts.

Seamounts form where sediment has built up or submarine volcanoes exist. Some sea mounts are isolated, while others appear in chains called volcanic island arcs. Some sea mounts, called guyots, are extinct volcanoes with flat tops. Scientists think that these underwater mountains were once mountains, but their tops were worn away by waves. Far out in the middle of the oceans, there is a belt of elevated floor called the "mid-oceanic ridge." The depth here is between 2 and 4 km (6500 and 13000 ft). The deepest parts of the ocean are deep-sea trenches, which are elongated trenches that run along the edge of certain continental shelves. The depth here can be from 5 to 12 km.

The figure above shows features of the ocean floor. Identify each feature by writing the correct letter in the spaces provided.

Abyss ____ Guyot ____ Abyssal Plain ____ Mid Ocean Ridge ____ Continent ____ Ocean trench ____ Continental Shelf ____ Seamount ____ Continental Slope ____ Volcanic Island Arc____

Mapping Techniques Name: __________

 

Techniques for mapping the ocean floor have changed quite a bit over the years. In the late 1800's, oceanographers dangled weighted lines over the edge of the boat, in order to determine how deep the water was.

In the 1920's, scientists learned to used echo sounders to map the ocean floor. Pulses of sound were sent into the ocean, and then the reflected signals were picked up by boats or submarines. The size (diameter) of the reflected echo relates to the depth of the ocean in that area. By the 1950's, the sounders were accurate to within 2m, and by the 1960's there was enough data collected to make a topographic map of the ocean floor.

In the 1990's, the use of SONAR (SOund NAvigation Ranging) became common for mapping. A echo sounder is towed behind the vessel and sounds out narrow sound waves, which reflect (or “echo”) off of objects in the water.

Sound waves travel through water at a speed of 1500 metres per second. Scientists send out a signal, and measure the time it takes for the echo to return to the transmitter. Let us say a sound wave makes it from the transmitter to the receiver in 10 seconds. The sound wave takes 5 seconds to reach the bottom and five seconds to return. Therefore, the depth of the ocean floor is 7500 m (1500 m/s x 5 s).

Complete the chart below. The first column shows the amount of time it takes for a sound wave to make a round trip using SONAR. For each time, give the depth of the ocean floor in metres (m).

Length of Time (s) Depth (metres)

1. 2 seconds

2. 6 seconds

3. 12 seconds

Complete each statement using a term or terms from the list below. Write your answers in the spaces provided.

Continental shelf Marianas Mid-Ocean Ridges Trenches continental slope basins Sharply oceans gradually

1) Most of the Earth’s water is found in the _____________. 2) The oceans lie in huge _____________. 3) The part of the continent that is under the ocean is called the ____________. 4) The continental shelf slants _____________. 5) At the end of the continental slope the ocean floor drops _____________. 6) The deep-sea basin (abyss) starts at the end of the ________________. 7) Mountain ranges in the middle of the ocean are called _____________. 8) The deepest places along the ocean floor are _____________. 9) The deepest trench in the world is the _____________ Trench.

1. Match each term in Column A with its description in Column B. Write the correct letter in the space provided.

Column A Column B

______ 1. water planet a) underwater mountain ranges ______ 2. continental shelf b) deepest part of the ocean ______ 3. plain c) flat area ______ 4. trench d) low part of a continent covered by ______ 5. mid-ocean ridges the ocean e) earth

2. True or False: ______ 1. The earth is the only planet. ______ 2. Only our planet has a lot of water. ______ 3. The earth’s water layer is called the atmosphere. ______ 4. The continental shelf has a gentle slant. ______ 5. The continental slope has a gentle slant. ______ 6. The deep sea floor starts at the beginning of the continental shelf. ______ 7. A mid-ocean ridge is a high place on the ocean floor. ______ 8. The ocean floor has some flat places.

OCEAN FLOOR SEDIMENTS

Four main classes:

1. Oozes:

• sediments made from microscopic ___________

• ___________ooze: contain calcium carbonate

• ___________oozes: contain silicon dioxide

2. Muds and Clays:

• mixtures of fine ___________that settle on the ocean floor

• May come from ___________, ash/dust from ___________, icebergs

3. Turbidites:

• deposits made by ___________currents (these are currents that sweep material down the submarine canyons and out over the abyssal plains)

• Form ___________beds

4. Authigenic Sediments:

• Authigenic (means formed in place) so these sediments don’t settle on the bottom but form ___________on the seafloor (eg. Manganese nodules)

Ocean Floor Sediments Refer to Page 323 Topic 2 and Pg. 336/337 Topics 14-17

1. Fill in the blanks.

Authigenic Cores Dredge Muds Oozes Turbidites

A. Samples of the seafloor are obtained in cylindrical sections called _________ or they are scooped up off the floor in a __________.

B. __________ are made up of microscopic shells.

C. Mixtures of variously sized fine particles that have settled on the ocean floor are called ____________.

D. ____________ are deposits made by currents that sweep material down submarine canyons and out over the abyssal plains.

E. Sediments that formed directly on the sea floor are called __________________ sediments.

2. Cores obtained from the ocean bottom have been up to 1500 thick. What have scientists been able to learn from examining these cores?

3. What are the two kinds of oozes, and what minerals do each of them contain?

a. _____________: ________________________

b. _____________: ________________________

4. Why do calcareous oozes not occur below a certain depth?

5. Name three sources of material for muds.

a. _______________________________________________________________

b. _______________________________________________________________

c. _______________________________________________________________

6. What is a graded bed, and why are they formed by turbidity currents?

7. What is the best-known example of an authigenic material, and why are they important?

SECTION B: IDENTIFICATION OF OCEAN SEDIMENTS

Label each of the following materials as being an “ooze”, “mud”, turbidites” or “authigenic sediment”:

1. Shells of Globigerina ____________________

2. 0.00024 mm to 0.04 mm flakes of clay ____________________

3. Manganese nodules ____________________

4. Graded beds formed far from coastal areas____________________

5. Diatomaceous sediments ____________________

6. Sediments deposited from melting glaciers ____________________

7. Sediments formed from an undersea landslide____________________

8. Sediment formed from radiolarian shells ____________________

9. Masses formed at the rate of 1 mm per 1 million years ____________________

10. Fine ash and dust from volcanic eruptions. ____________________