P a g e | 1 Seniors Oceanography Packet Name________________________ Below is work not completed from Quarter 2. Those of you have been notified of the pages you need to complete in order to earn credit. A reminder you can only receive a maximum letter grade of D. Pages 19 to 22 are to be used for the alternative exam assignment. P a g e | 2 Assignment 1: Currents Map Lab Procedure: A. Using the map provided on page 3, label all of the world’s currents by name. Color each current with the color that corresponds to the current’s temperature. Color the cool currents blue, and color the warm currents red. B. Next, answer all of the current questions below. Questions: 1. In the Northern Hemisphere, the circular pattern that gyres form from currents move in this direction: ___________________________________________ 2. What direction is the circular pattern that the gyres move in within the Southern Hemisphere? _______________________________________________ 3. In what latitudes do warm water currents originate? __________________________ Why are they warm? __________________________________________________ 4. In what latitudes do cold water currents originate? ___________________________ Why are they cold? ___________________________________________________ 5. Which current could circumnavigate the globe (carry a vessel around the world) without the assistance of any other current? _______________________________ 6. If you were traveling from South America to Australia, which three currents would you take to arrive there? __________________________________________________ 7. Explain the Ekman spiral: _______________________________________________ __________________________________________________________________ What is the net movement of a current in an Ekman transport? ___________________ __________________________________________________________________ 8. If you were to drop a message in a bottle off the coast of Virginia, it would be carried by what current? _________________________ In what direction? _____________ 9. Which global wind belt produces the current off of the coast of Virginia? ___________ 10. Which global wind belt produces the Brazil & South Equatorial currents? ____________ 11. Which currents would bring icebergs south from the North Polar region? _________________________________________________________________ P a g e | 3 P a g e | 4 Assignment 2: CURRENTS Article Ocean and atmospheric circulation play an essential role in sustaining life by moderating climate over much of Earth's surface. Two circulation patterns dominate the ocean: wind-driven currents in the upper ocean and density-driven currents in the deep ocean. Wind-driven currents are maintained by energy transferred by the winds to the ocean surface. Surface currents form gyres roughly centered in each ocean basin. Viewed from above, currents in these subtropical gyres flow in a clockwise direction in the Northern Hemisphere and a counterclockwise direction in the Southern Hemisphere. Global surface current patterns are driven by the wind, impacted by the barriers to water flow (land masses) & the rotation of the earth. Western boundary currents (Gulf Stream) are among the fastest surface currents in the ocean. Western boundary currents occur along the western boundaries of ocean basins and flow toward the poles - north in the Northern Hemisphere and south in the Southern Hemisphere. Water moving in these currents transport large amounts of heat from tropics to upper latitudes. Eastern Boundary currents (California current) are slower, shallower, and wider than western boundary currents. These currents transport colder waters from the poles to the tropics. Once there the water is heated and transported poleward in the western boundary currents. How does this impact our lives? For centuries, people have used ocean surface currents to explore the world and transport goods to market. Today we use them to take the most efficient path to save fuel in the shipping industry, to win a sailboat race, and to track pollution such as oil spills or assist in search and rescue operations. Ocean surface currents contribute to studies of severe weather such as hurricanes, short-term climate phenomena such as El Niño, and long-term climate variability. OCEAN EDDIES An eddy is a loop of current that is cut off from the main current; in other words a small, spinning current. They are comparatively tiny, short-lived circulation patterns in the ocean. Ocean eddies move at speeds of about 0.5 knots (about 0.9 kilometers or 0.6 miles per hour) and may occasionally persist for many months. Eddies can be over 300 km (about 200 mi) in diameter. Such large eddies can be seen easily from space by thermal infrared P a g e | 5 sensors. The picture above shows the Gulf Stream and many eddies. The Gulf Stream is a Western Boundary current that separates two distinct water masses. The northwest water mass of nearshore water to the north is colder and more fertile than the water that is to the southeast of the Gulf Stream (called the Sargasso Sea). The nearshore water has a temperature of less than 10°C (50°F), while the temperature of the Sargasso Sea ranges from 15°C to 25°C (59°F to 77°F). In general, whether an eddy is cold-core or warm-core depends on which side of the Gulf Steam the water came from. A cold-core eddy is a ring of Gulf Stream water that flows counterclockwise around a cold, less salty mass of water. It is formed when a branch of the warm Gulf Stream “wanders off” and captures a piece of colder water from the northwest. A cold ring can be tracked for months before it dissipates into the surrounding ocean waters. A cold ring traps the nutrient-rich water from north of the Gulf Stream and transports both nutrients and plankton into the relatively barren Sargasso Sea. A warm-core eddy forms when water from the edge of the Gulf Stream breaks off from the current and moves into the colder water. Because the current is warmer than the surrounding water it is called a warm-core eddy and has a clockwise flow. This eddy drifts towards the coast and usually dissipates within a few months as it collides with the shallow continental shelf. Warm-core eddies trap and transport a variety of different kinds of animals normally not seen in colder waters. Questions – Answer in complete sentences. 1. What are the two types of ocean circulation current patterns? 2. What is a western boundary current? 3. What is the driving force behind the Gulf Stream? 4. If you were the president of a company that used ships to transport all your goods explain why you would choose either a western boundary current or an eastern boundary current. 5. In what ways are ocean currents used today? P a g e | 6 6. What is an eddy? 7. What is the typical temperature of the water in the Sargasso Sea? 8. What does a cold core eddy transport? 9. Which direction does a warm core eddy flow? 10. What causes a warm core eddy to dissipate? P a g e | 7 Assignment 3: Alternative to Plastic Ocean Plastic Micro-Debris Lab/SIO, Directions : Read the background, graph the data and answer the questions. Background: Plastic debris in the North Pacific Gyre (the Great Pacific Garbage Patch) are a concern at many levels. The introduction of plastic debris has recently become of interest to many studies and research expeditions. Gregory and Ryan (1997) reported that plastics comprise 60-80% of marine debris. It is typically composed of fragments of manufactured plastic products. (McDermid & McMullen 2004). Most plastics do not biodegrade. Unless they are removed, they remain in the sea for hundreds of years, breaking up into ever-smaller particles (Leahy 2004). Plastic does not just disappear when it enters the ocean, but rather is broken down through processes such as photodegradation. Photodegradation is thought to be one of the driving forces behind plastic breakdown, and occurs when ultraviolet waves of light from the sun break apart the bonds that hold plastic together, causing it to be brittle. This type of degradation creates microscopic pieces, difficult to see with the naked eye, but continually traveling throughout the North Pacific Gyre. The possibility of plastic accumulating in the ocean from countless sources raises many questions; notably because of the lack of effective methods to remove it. Information about the abundance and occurrence of plastic micro-debris particles, as well as quantitative information on how plastic particles change over time is limited (Gilfillan, 2009). Data: Quadrants <1mm 1mm-2mm 2.01mm-3mm 3..01mm-4mm >4mm Number of Pieces Number of 7 5 2 1 0 Styrofoam Quadrant Pieces A1 Number of 12 4 5 2 1 Plastic Pieces Number of 15 7 5 2 3 Styrofoam Quadrant Pieces A2 Number of 8 2 3 6 8 Plastic Pieces Number of 11 8 5 3 1 Styrofoam Quadrant Pieces B1 Number of 13 9 8 6 5 Plastic Pieces P a g e | 8 Number of 14 12 3 5 7 Styrofoam Quadrant Pieces B2 Number of 5 6 7 3 2 Plastic Pieces Number of 10 8 9 3 1 Styrofoam Quadrant Pieces C1 Number of 9 7 11 7 3 Plastic Pieces Number of 11 9 12 8 2 Styrofoam Quadrant Pieces C2 Number of 14 12 6 7 4 Plastic Pieces Data Analysis Place the totals from the data on a chart like the one provided. P a g e | 9 Questions (answer in complete sentences for full credit) 1. Do scientists know how much plastic exists in the ocean? 2. Explain why plastic is such an issue in the ocean. 3. Explain how plastic breaks down in the ocean over a long period of time. 4. Which currents are most associated with the Great Pacific Garbage Patch? 5. Explain why America is more responsible for the trash in the Great Pacific Garbage Patch than Europe.