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Unit 1, Part 2 Study Guide Ocean Basins – low spots on earth completely or partially surrounded by land Oceans – basins where water has collected and remained over millions of years What are the earth’s 5 main ocean basins and oceans? 1. Pacific ocean (largest) 2. Atlantic ocean (2nd largest) 3. Indian ocean (3rd largest) 4. Southern ocean (Antarctica) (4th largest) 5. Arctic ocean (smallest) Continental Drainage System – created by glaciers as they eroded the land. Water from rain and snow drains downhill and collects in continental drainage systems/basins such as lakes, rivers and oceans! Canada’s 5 Major Drainage Basins FYI: Refer to page 27 of your book for Newfoundland and Labrador’s drainage basins. 1. 1. Volcanic Action - Page 40 – 41 of textbook. Basically, 4.5 billion year ago, the planet was a hot ball of molten (melted rock). As the outside of the earth cooled, heat was still released from deep inside through volcanoes. Water trapped inside the volcanoes material was released into the atmosphere as water vapor. When the vapor cooled and condensed it fell to the earth as precipitation which flowed downhill and collected in ocean basins. 2. Plate Tectonics - Page 40 – 44 of your text book. - Plate tectonics is the theory that the earth was once a giant supercontinent called Pangea. Over time, the supercontinent broke apart and large pieces of land sitting on plates (large pieces of slow moving rock) began to move away from each other. - As plates move apart or come back together, they form trenches and mountains. This plate movement has the greatest influence in shaping the ocean floor. 3. Erosion - Erosion is the removal of sediment, sand, soil, rock and other materials by glaciers, wind and/or water. - Many years ago, glaciers moved very slowly and eroded away the land creating many of the continental drainage systems we have today. 4. Glaciation - Many years ago, glaciers moved very slowly and eroded away the land creating many of the continental drainage systems we have today - The were and still are a major force of erosion Using a Diagram, illustrate a typical oceanic basin from coastal shoreline to mid ocean ridge including continental shelf, continental slope, abyssal plain and mid-ocean ridge! Continental Margin – ocean basins begin many kilometers out to sea. The area between the basin and the shoreline is the continental margin, made up of the continental shelf and the continental slope. Sediments, which are created from rocks eroded by weather, are carried by rivers into oceans and eventually end up into oceans, settling on the continental shelves or on abyssal plains! Continental Shelf – found under water between the coastline and the edge of the basin. They slope gradually away from the land before dropping steeply. The continental shelf off of Newfoundland, toward the Grand Banks, is 480 km, one of the widest in the world since most are only 80 km wide! Water can be anywhere from 30 m to 600 m deep on the shelf! Continental Slope – the steeply sloping area on the end of the continental shelf. They are usually less than 200 km wide and drop approximately 3 km downward Abyssal Plain – the floor of the ocean basin which is somewhat flat It is made up thick sediment up to 1 km thick that usually reaches the plain by underwater landslides usually started by earthquakes or the pile up of sediment. Mid-Ocean Ridges – chains of volcanic mountains rising up from the middle of the ocean floor Youngest part of the ocean floor and still being formed today Can be 1000 km wide Can rise 1000 – 3000 km above the sea floor Largest is the Mid-Atlantic ridge in the Atlantic Ocean Sonar – Sonar uses sound waves to map out the ocean floor. The depth of water is found by sending sound waves directly down from the boat and measuring the time it takes for the signal to hit the sea floor and bounce back to the surface Fish finders use Sonar technology to find fish Satellites – Satellites orbit far above earth and can send and receive information from earth Satellites can use radar and other technologies to measure different features on earth such as mountains, trenches and even the ocean floor! An advantage to using satellites is that they can measure large areas of ocean in a very short time Satellites can also send and receive data in all kinds of weather, both day and night! Satellites can also receive information from buoys that are anchored to the sea floor and can help collect information about water and air temperature. They satellites can transmit this information all over the world! Many satellites orbit the earth. This photo just shows some of the newest satellites designed by NASA. Underwater photography and videography – underwater cameras and video cameras Cameras towed by ships can take thousands of high resolution photographs a day to share with the world New deep sea cameras and video cameras can be used up to 6000 m below the ocean surface These cameras have allowed scientist to explore the ocean floor and find new species! The NEPTUNE deep sea camera has 2 photo cameras, a video camera, lights and a battery pack that can go 6000 m down into the ocean! (picture above) Deep Sea Submersibles – small but extremely strong vehicles that are capable of going deep into the ocean The most detailed information we have about the deep ocean come from submersibles There are 2 types of submersibles: o 1) Manned – carries people in it; can be dangerous and cannot stay underwater for as long o 2) Remotely Operated Vehicle (ROV) – someone controls the vehicle from the ship; less dangerous and can stay underwater for longer Scientists are working on a 3rd submersible called an automated underwater vehicle which can use artificial intelligence, needs little control from people and can stay underwater for months at a time. This is a manned submersible. People sit inside, drive the vehicle and make observations through the large glass window. An ROV is much smaller and often has mechanical hands/arms for performing tasks. It is run using cameras and is connected to the ship by a tether rope. Humans control it much like playing a video game! Diving – SCUBA diving refers to wearing diving suits and using oxygen tanks to swim underwater. SCUBA is an acronym for Self Contained Underwater Breathing Apparatus! Commercial divers are those who are hired to perform underwater jobs Technical diving allows divers to dive deeper than 40 m (130 ft) Divers can be used to explore shallow waters, used by police and army for searches and can even take underwater photo and video. Divers cannot be used to explore the deep ocean How have technologies used to study the ocean floor improved over time? Divers can now dive deeper than ever before and for longer Submersibles have replaced divers and can now explore deeper and stay underwater longer Sonar has replaced wire line depth probes and is more efficient and accurate Satellites are not affected by darkness or weather, can send information instantly all over the world and gathers large amounts of information very quickly Identify strengths and weaknesses of technologies used to study the ocean Strengths Sonar - Accurate - Scientists have been able to map out mountains, valleys and canyons on the ocean floor Satellites -Cover large areas quickly -Sends information worldwide quickly -Not affected by weather or darkness -Takes thousands of high resolution photos in a day -Creates photos and videos to be observed later -ROVs are safe and can stay underwater for long period s of time -Allows us to explore deepest parts of the ocean -Hand on observation -Good for shallow waters because it is cheap and easy Underwater cameras Submersibles Diving Weakness -Sonar can harm marine animals (confuse animals that use sound for mating and feeding) -Can be affected by weather and waves -In space and difficult to locate to fix -Usually remains in space as space junk - Affected by muddy waters and waves - Cannot go very deep -Manned can be dangerous and cannot stay underwater for long - Expensive and technical -Cannot be used to explore deep ocean -Safety issues when using humans It is important to realize that no single method can collect enough data to give us a complete picture of the ocean floor. We need to use evidence from a variety of sources to get an accurate view! * Provide examples of public and private Canadian institutions that support scientific and technological research involving oceans. 1. Environment Canada – a Canadian Government department that is responsible for environmental programs that help protect the environment and make sure it is being used properly. It also keeps a close eye on our weather. 2. Federal Fisheries – Fisheries and Oceans Canada is another Canadian Government department that makes the rules around fishing and hunting in the oceans. 3. Ocean Sciences Centre – an ocean research office located in Memorial University 4. C-CORE (Centre for Cold Ocean Research) – another Memorial University research centre Ocean Current – a continuous, directed movement of water - Newfoundland is affected by 2 ocean currents: 1. The Labrador Current – a cold water current which flows from the Arctic Ocean down past Newfoundland 2. The Gulf Stream – a warm water current which flows from the top of Florida up past Newfoundland and then across the Atlantic Ocean When these currents meet, the warm and cold water combination often leads to fog which is why St. John’s experiences a lot of fog! - The 2 types of ocean currents are: 1. Surface currents – currents that exist within the top 200 m of ocean 2. Deep water currents – currents that exist beyond 200 m of the ocean What causes surface currents? 1. Wind – the wind is a mass of air moving from one are to another because of uneven heating of the earth’s surface. The direction and speed of wind blowing over the water affects surface currents 2. Earth’s spin – the earth spins counterclockwise from West to East. As currents flow over the spinning earth their paths change. This change in direction is called the Coriolis Effect. Because the earth is always spinning, air currents flow clockwise in the northern hemisphere and counterclockwise in the southern hemisphere. 3. Shape of Continents – When currents hit a solid surface (land) they are forced to change direction. Continents either deflect currents North or South. What influences the formation and movement of deep water currents? 1. Temperature – temperature differences in water can cause vertical convection currents. Warm water will continually be pushed to the surface by cold water that will sink. 2. Salinity – Water with high salinity is denser and will sink more quickly. Areas with high evaporation rates are saltier and denser. This water will sink and form a downward moving density current. When water freezes, salt is left behind. At the north and south poles, water is denser. Water near the equator is also saltier and denser. Upwelling areas – an area where deep cold water is pushed to the surface and carries nutrient rich ocean water with it which often attracts organisms. The collision of the Labrador Current and the Gulf Stream has created a nutrient rich upwelling area off Newfoundland called “The Grand Banks” which has been known as one of the world’s most productive fishing grounds! Wave – moving water that transfers energy Waves are generated when the energy of wind is transferred across the surface of a body of water. The sizes of waves are influenced by the speed and duration of wind as well as the size of the water body it is passing over! Features of a Wave Crest – the top of the wave Trough – the bottom of the wave Wave length – the distance between the crests of 2 waves Wave Height – the height of a wave from the bottom of the trough to the top of the crest * As waves approach the shoreline, the wave length decreases but the wave height increases. Ocean waves – Ocean waves begin out on the open ocean, thousands of kilometers away from shore. As they come close to shore, their wave length decreases but their wave height increases Swells – A long, smooth wave that moves steadily without breaking on shore. They are caused by winds and storms far out on the ocean. Breakers – when waves hit the shoreline they are called breakers. Tsunami – large waves that are set in motion by earthquakes on the ocean floor, landslides or volcanic eruptions near shorelines. In 1929, Newfoundland experienced a Tsunami. It affected the Burin Peninsula on Newfoundland’s south coast. It was caused by an earthquake that happened in the middle of the Atlantic Ocean. When waves come in contact with the shoreline, the energy is used to erode and reshape the coast. Most shoreline processes are related to the action of waves! Weathering – the breakdown of rocks into smaller particles Erosion – the movement of weathered particles Deposition – when eroded material is dropped and left behind * Wave interactions with shorelines depend on: 1. Shape of the shoreline – more energy will hit headlands than bays! 2. Slope of the shoreline – a shallow slope will have more sand and material deposited. Steeper slopes will have more erosion. 3. Type of rock material – small particles erode more easily and larger particles are left behind. Also, less resistant rock types, such as sandstone, will erode faster than more resistant rock types such as shale (example: the Red Rocks in St. George’s will erode faster than the cliffs of Bell Island, Conception Bay) 4. Wave energy – more powerful waves will create more erosion Waves have the power to erode shorelines and deposit sediment on the shore. Tides work with waves and determine the range of shorelines that can be affected by wave action! Waves and Tides are the 2 main factors that shape shorelines! Headland – a part of the coastline that comes out further into the ocean than the land next to it Bay – indented area of coastline usually between 2 headlands * Wave energy is strongest at the headland and then spreads out as it reaches the bays! Sea caves – an area along a headland where ocean currents have carved a hole into the land Sea arches – an area along the headland where ocean currents have eroded entirely through the headland Sea stack – an area along the headland where ocean currents have eroded entirely through the headland and the top has fallen in to create a separate piece or standing rock separated from the headland Beaches – areas where sediment has been deposited. They are constantly changing because of waves and wind. They narrow in winter because of larger waves and are wider in summer because of gentle waves. Shoal – a place where the sea is shallower; often times it is a sand deposit and can be seen above the water Sand bar – a large ridge of sand formed by waves and currents Technologies used to contain damage from tides and waves: 1. Breakwater – a long structure off the coast that decreases the intensity of waves hitting the shoreline 2. Jetty or Wharf – structures that extend out from the coast to prevent drifting and slows down shoreline erosion 3. Sea Walls – walls that run parallel with the sea, usually used in areas where the sea level is rising Tide – the daily rise and fall of the ocean Tides are created by the gravitational pull of the moon and the spinning of the earth Both the sun and moon influence the earth’s water, but the moon has the greater influence because it is closer to the earth! High tides occur on 2 sides of the earth at the same time – the side facing the moon and the side opposite! While these 2 sides experience high tide, the remaining portions of the earth will experience low tides! Tidal Range – the difference between the height of water at high tide and at low tide. For example, if water was 7 m high at high tide and 2 m high at low tide, the tidal range would be 5 m. * A normal tidal range is approximately 0.6 m * The largest tidal range in the world occurs in the Bay of Fundy, Canada. The tidal range can get as high as 20 m! There are 2 different tides: 1. Spring Tides – the largest tidal range happens when the Earth, moon and sun are in a line. They occur because of the greatest gravitational pull of the moon. Spring tides happen twice a month: 1. At full moon – earth is between the Moon and Sun 2. At new moon – when moon is between the earth and the sun 2. Neap Tides – smallest tidal range happens when the sun and moon are at right angles to each other. Occur because of smaller gravitational pull of the moon Neap tides happen twice a month: 1. First quarter of the moon – moon is on top of the earth 2. Third quarter of the moon – moon is below the earth What is the difference between heat capacity and specific heat capacity? Heat capacity – a measure of how long it takes a substance to heat up or cool down Specific heat capacity – the amount of heat needed to raise the temperature of a substance by 1 degree Celsius * Water has a very high heat capacity, which means it takes a long time to warm up and cool down. Therefore, oceans can store large amounts of heat and currents that transport this heat to other parts of the world affecting their climate! Convection – transfer of heat Thermals – when the sun warms the surface of the ocean the heat is transferred to the air above it through convection. Since the air is warm and less dense, it rises. When it cools down, it becomes denser and sinks back down toward the ocean. In the daytime, a cool breeze comes off the ocean, is warmed on land and when it cools goes back to the ocean. The opposite is true at night where the cooler land breeze blows out and is warmed over the ocean. This helps days from getting too hot and nights from getting too cool. How do oceans moderate climate? Oceans stay warmer than land through the fall and winter because of its high heat capacity. Also, the oceans stay cooler in the spring and summer. This prevents the areas from being extremely hot in summer or cold in winter. Newfoundland and Labrador Climate Newfoundland and Labrador climate is regulated by the cold Labrador Current and the warm Gulf Stream. This results in fog and quick changes in temperatures. Fog – when the tropical, warm, moist air of the Gulf Stream blows over the cool air of the Labrador Current, it cools and condenses as fog. Temperature changes – our temperatures are controlled by the cold Labrador Current transferring arctic winds and the warm Gulf Stream which transfers warm, tropical winds. This moderates our climate making it not too cold and not too warm! The local temperature will depend on which wind prevails! El Nino and La Nina Both are examples of global weather phenomenon and have opposite characteristics as summarized in this chart. El Nino La Nina Decrease in trade winds Increase in trade winds Warming of the ocean Cooling of the ocean More extreme drought or flooding Less drought or flooding Decrease in marine productivity Increase in marine productivity Effect on Trade Winds (winds that blow near the equator and generally blow toward the west) Effect on Ocean Temperature Effect on weather Effect on marine productivity (ocean life)