The Hydrosphere

1. The Hydrosphere 8th Grade Curriculum – Developed for NCDPI - 2008

2. Properties of Water • Polarity- (H + O -) water consists of 2 hydrogen atoms which have a slight + attraction between the 2 protons to the 2 electrons of the oxygen atoms. This causes water to be attracted to other polar molecules and gives water its many unique properties. • Buoyancy-the upward force that keeps objects afloat. When placed in water an object will float if its buoyancy is greater than its weight and sink if weight is greater than buoyancy

3. Archimedes’ Principle - the weight (down) of the displaced fluid is equal to the buoyant force (up) {this is how a cruise ship floats}

4. Properties of Water • Density- compares the mass to the volume in a ratio. Water has a density of 1 g/cm3so it is used as a comparison for substances that sink or float • Surface Tension-is the cohesion of water molecules at the surface. They bead together at the surface. These “sticky” molecules create surface tension. Ex. Water strider can “walk” on water

5. Properties of Water • CapillaryAction-the ability of water to defy gravity and climb uphill. Ex. Roots of a plant send water upward to the stem and leaves • Adhesion- the ability of water to stick to other substances. Ex. Water glass sticks to coaster • UniversalSolvent-water can dissolve so many substances due to the polarity of its molecules

6. Properties of Water • Specific Heat-the amount of heat to raise 1 gram of a material 10C. Water has a specific heat of 4.179 J/g0C.ex.ocean water may not reach 250C till late July even though there have been 20 days with temperature of 350C. • Water has a HIGH specific heat

7. Oceans—97% of water found here Fresh water—3% of water found here Fresh water distribution: Ice: 76% Groundwater: 23% Surface Fresh Water: 0.34% Atmosphere and soil: 0.037% The Structure of Hydrosphere

8. Understanding Where Your Water Is Located—Oceans and Ice • What bodies of water hold the largest amount of water? • Oceans—the largest bodies of water on Earth (contain salt water only) • What features house water as ice? • Icebergs: a large piece of freshwater ice floating in open waters • Glaciers: any large mass of ice that moves slowly over land • *permanent snow areas also “house” water as ice

9. Fresh Water Locations—Surface Water • What is the difference between a watershed and a river basin? • Both terms describe land that drains into a river, stream or lake • River Basin: the term used to describe an area that drains into a large river • Watershed: the term used to describe an area that drains into a smaller river or stream

10. Your ecological address:

11. North Carolina’s 17 River Basins My ecological address is: Neuse River Basin Cape Fear River Basin

12. Fresh Water Locations—River Basins and Watersheds • Larger river basins are made up of many interconnected watersheds • Example: Cape Fear and Neuse River Basins are made of many small watersheds • Raleigh is in the Neuse River Basin. • The water in a watershed runs to the lowest point—a river, stream, lake, or ocean

13. Fresh Water Locations—Rivers, Streams, and Lakes • What is a river? • A large channel along which water is continually flowing down a slope—made of many streams that come together • What is a stream? • A small channel along which water is continually flowing down a slope—made of small gullies. These tributaries dump water into a larger river. • What is a lake? • A body of water of considerable size contained on a body of land; water collects in the basin over time

14. Fresh Water Locations--Groundwater • What is groundwater? • The water found in cracks and pores in sand, gravel and rocks below the earth’s surface • What is an aquifer? • A porous rock layer underground that is a reservoir for water

15. Other Surface Waters • What is a wetland? • An area where the water table is at, near or above the land surface long enough during the year to support adapted plant growth • What are the types of wetlands? • Swamps, bogs, and marshes • Swamp: a wetland dominated by trees • Bogs: a wetland dominated by peat moss • Marshes: a wetland dominated by grasses

16. The Water Cycle The water cycle is a renewable natural cycle. • Precipitation is when water falls to the earth as rain, sleet, snow, or ice. • It can be absorbed into the ground called infiltration and stored as groundwater. • It can become filteredand flow to rivers and streams.

17. Water Cycle • Evaporation is when water returns to the atmosphere as water vapor. • It can also return through plants called transpiration. • When it returns, it is naturally filtered because only the molecule evaporates. • As the water vapor gathers and cools in the atmosphere it will condensate and eventually fall again as precipitation.

18. Water Pollution • Water pollution is the addition of any substance that negatively effects the water and living things in the water. The amount of potable water depends on the quality of the water. • Examples of water pollution include: treated wastewater, runoff, toxic chemicals, municipal sewage, motor oil from cars, fertilizers, detergents, pesticides, . . . .

19. Water Pollution • When waste is deposited in water, solids particles settle to bottom and the concentration of the chemical is diluted by the water. Water naturally renews itself through the water cycle & filtration through wetland environments. • When too much nutrient waste that is high in nitrates & phosphates enter the water, algae can begin to grow uncontrollably due to the “nutrient” matter.

20. Eutrophication

21. Water Pollution • Eutrophication occurs when the lake or pond or stream is overtaken by algae. It has a “green scum” covering the surface and chokes out oxygen from entering the water for fish and thus fish kills can occur.

22. Eutrophication

23. Water Pollution • Sediment pollution is the number one cause of water pollution in NC rivers. What would cause sediment runoff? • How would sediment harm the water quality? • Effluent describes any waste material discharged into the environment.

24. Point Source Pollution • Point source pollution- can be traced to its point of origin. It can be a pipe, smokestack, culvert, underground container that is pouring or leaking smoke, industrial waste, or storm sewer wastewater into a body of water

25. Non Point Source Pollution • Non point source pollution- cannot be traced to a single point of origin. Ex. Your car exhaust or engine leaks oil, leftover salt from a winter storm runs into the river, boat dumps its sewage into river after a day on the water, . . .

26. Biomagnification • When chemicals enter the environment through groundwater or surface water, they can enter the food chain. • First level producers absorb the chemical, then the first level consumers eat the producer and absorb more of the chemical. At each level of the food chain, more of the chemical is absorbed and the impact on the organism is magnified.

28. Man’s Impact on our Waters • Choose one article in pairs from the Estuaries supplement. Each person reads it and summarizes it. • Now decide how you will answer the question– How does man impact the water? • Create an public service ad to help the public understand why they have an important role in helping conserve and clean our waterways.

29. Ocean Technology • http://www.nurp.noaa.gov/Tech.htm • http://www.coolclassroom.org/cool_projects/lessons/miniunits/lesson2.html

30. What technology is used to study the oceans? • As early as 600 B.C. the Phoenicians were exploring the ocean surface by ship • In 1000 the Chinese discovered the compass so navigating the ocean became easier • 1825 SCUBA gear was invented so man could spend more time under the water exploring

31. Ocean technology • 1920’s SONAR (sound navigation and ranging) was invented due to a need to detect submarines. Another application is to use sound waves to map the ocean. • 1934- 1st Deep sea dive in a steel ball Now: submersible vehicles with humans; remotely operated vehicles from ship on the surface; Remote sensing- using satellites to photograph data from the ocean

32. Ocean technology • What factors have limited man’s ability to learn and map the ocean completely? • Remote sensing is using satellites or aircraft to gather data from afar. Then when the scientist go to the site to verify it is called ground truthing. Ex. Mapping ocean surface temperatures

33. Ocean Technology

34. Waves, Tides, Currents • Waves are a movement of energy through a body of water. • The size of a wave is determined by the strength of the wind and the length of time it blows. The energy moves toward the shore but the water remains in place.

35. Waves, tides, and currents • Near the shore wave height increases and wavelength decreases as the wave’s energy runs out of seafloor. A tsunami is a giant wave caused by an underwater earthquake. Waves shape a beach by erosion and deposition.

36. Waves, tides, and currents • The daily rise and fall of earth’s waters on its coastlines are called TIDES. The interaction of gravity of the earth, moon, and sun cause the tides.

37. Waves, tides, and currents • The earth, moon, and sun change positions over the course of a lunar month thus affecting the tidal bulge in a month. A spring tide occurs when all three are in a horizontal alignment so the distance between high and low tide is at its greatest. A neap tide occurs when the sun, earth, and moon are at a right angle and there is the least difference between high and low tide.

38. Spring and Neap Tides

39. Waves and Tides

40. Waves, tides, and currents • Surface currents affect water to a depth of several hundred meters. They are driven by the wind. • Currents move in circular patterns due to the rotation of the Earth. It causes the winds and currents to curve. This is called the Coriolis Effect.

41. Waves, Tides, and Currents • The Gulf Stream in the Atlantic is the largest surface current carrying water from the Gulf of Mexico to the northeast. It warms the climate of many coastlines as it travels north. Ex.Norway is warmer than nearby countries due to the Gulf Stream

42. Waves, tides, and currents • El Nino is an abnormal climate event that occurs every 2-7 years in the Pacific. The unusual pattern of winds causes a large layer of warm water to move toward South America. It causes weather problems worldwide. • Deep water currents are caused by dense cold water that sinks to the bottom and moves toward the poles. It takes 1000s of years for the deep water currents to circle from pole to equator and back.

43. Waves, tides, and currents • Density differences in ocean water is due to salinity, temperature and depth of the water. • Upwellings bring cold water to the surface in the open ocean. Along with the movement of water nutrients and food for fish are brought to the surface. Fish follow upwellings.

44. Ocean Chemistry • What caused the oceans to become salty? (pg. 155) • Ocean averages 35 to 37 parts salt to parts water. • Salinity is defined as the total amount of dissolved salts in water. • Seawater has a higher density than freshwater and freezes at a lower temperature. • Estuarine water is a mix of fresh & ocean water.

45. Measuring Salinity

46. Ocean Chemistry • Surface water becomes diluted with freshwater after storms, rain, or where rivers dump into the sea. • Salinity is also affected by temperature and depth of the water. • Gases are found in ocean water. The CO2 and O2 cycle occurs to supply dissolved oxygen to animals and CO2 to plants in the ocean.

47. Ocean Chemistry • Cold water contains less dissolved oxygen than warmer water. • Salts in the ocean NaCl, NaSO4 , CaCl2 , KCl, . . . Surface water 100-500 meters deep ~17.50C Transition Zone 500 meters to 1 km deep ~40 C Deep Zone 1 km to seafloor ~ -3.50 C

48. Ocean Habitats and Zones • The ocean is a huge community of living and nonliving things. The habitat zones of the ocean are: Intertidal zone, Nertic zone, open ocean zone. • In each zone, there are distinct physical factors such as the amount of sunlight, temperature, and water pressure. These factors determine which organisms live where. Organisms in the ocean are classified by where they live & how they move!

49. Ocean Habitats and Zones • Intertidal Zone – from highest tide line to lowest tide line • Organisms must be able to handle changes in salinity and temperature • Ex: hermit crabs, algae, sea anemones • Estuaries – coastal inlets where fresh water from rivers mix with salty water • “Brackish water” • Salt Marshes – ooze with smelly mud from plant and animal matter • Fish, crabs, shrimp, oysters all hatch and feed before going to ocean

50. Estimates include: 100,000 deaths/year marine mammals 1,000,000 death/year sea birds 3-4,000,000 deaths/year of fish http://www.pbs.org/kcet/wiredscience/rss/media/wirs102_it03_flotsom_480.mp4 Plastic pollution is ingested by marine animals and blocks the digestive tract or effects the swim bladder Fishing line, six pack rings, abandoned traps entangle birds and fish by the gills Ghost fishing traps marine mammals causing them to suffocate Ocean Pollution