1. © 2014 Pearson Education, Inc. Chapter 2 Lecture McKnight's Physical Geography 11e Lectures Chapter 9 The Hydrosphere © 2014 Pearson Education, Inc. Andrew Mercer Mississippi State University

2. © 2014 Pearson Education, Inc. Learning Goals of This Chapter Define the hydrologic cycle. Describe the moisture inventory of Earth. Describe the movement of water between the four "spheres" of Earth. Differentiate between the elements of the hydrologic cycle and their interrelationships. Compare the residence times of the elements of the hydrologic cycle. Identify the four oceans of Earth, and explain the inherent difficulties of specifying this number. Identify Earth's significant oceans, seas, gulfs, and bays.

3. © 2014 Pearson Education, Inc. Learning Goals of This Chapter Explain the salinity of the ocean and its origin. Describe the spatial patterns of ocean salinity, and explain the influencing factors. Explain the distribution and importance of carbon dioxide content of ocean water and the factors that influence it. Explain ocean water temperature and density patterns and their influencing factors. Differentiate between tides, currents, and waves and their motions. Explain tides and the tidal cycle. Explain why currents move and their impact on Earth.

4. © 2014 Pearson Education, Inc. Learning Goals of This Chapter Distinguish between surface and deep ocean currents and the paths that they follow. Explain the formation and significance of the Great Pacific Garbage Patch. Identify the main components of the cryosphere. Distinguish between the four types of ocean ice. Explain permafrost and the three different categories. Explain the construction hazards associated with permafrost areas. Identify the 15 largest lakes. Explain the formation of lakes and how humans alter lakes and create new ones.

5. © 2014 Pearson Education, Inc. Learning Goals of This Chapter Explain how lakes and reservoirs impact the environment and change over time. Define wetlands, and distinguish between swamps and marshes. Identify the world's largest rivers and major drainage basins. Define ground water. Define permeability and porosity, and explain their influence on groundwater movement. Explain the subsurface structure related to groundwater and the water table and the movement of groundwater through these zones.

6. © 2014 Pearson Education, Inc. Learning Goals of This Chapter Distinguish between springs, wells, and artesian wells and their subsurface structures that make water available. Explain recharge of groundwater. Describe the Ogallala Aquifer and the associated environmental problems and concerns.

7. © 2014 Pearson Education, Inc. The Hydrosphere The Hydrologic Cycle The Oceans Movement of Ocean Waters Permanent Ice—The Cryosphere Surface Waters Groundwater

8. © 2014 Pearson Education, Inc. The Hydrologic Cycle Bulk of Earth’s moisture (99%) is in storage in oceans, lakes, rivers, glacial ice, or rocks beneath the surface Remaining fraction involved in a continuous sequence of movement and change Movement is the hydrologic cycle

9. © 2014 Pearson Education, Inc. The Hydrologic Cycle Three primary movement types –Surface to air Ocean evaporation Vapor remains in air for a short time –Air to surface Precipitation – 78% falls on oceans and 22% on land Precipitation is the same as evaporation over long time scales

10. © 2014 Pearson Education, Inc. The Hydrologic Cycle Three primary movement types (cont.) –Movement beneath the surface – runoff Water collects in lakes and rivers and either penetrates ground or runs off if sloped Becomes part of underground water supply Reemerges as springs or becomes part of rivers and streams Residence times

11. © 2014 Pearson Education, Inc. The Oceans Vast majority of surface is oceans Number of oceans –Four principal parts Pacific – largest, occupies 1/3 of total Earth surface area Atlantic – less than half the size of the Pacific Indian – Slightly smaller than Atlantic Arctic – small and shallow Smaller bodies – seas, gulfs, and bays

12. © 2014 Pearson Education, Inc. The Oceans The primary oceans and seas

13. © 2014 Pearson Education, Inc. The Oceans Characteristics of ocean waters –Chemical composition Sodium and chlorine Salinity –Increasing acidity Carbon dioxide absorbed by ocean water creates carbonic acid Affects the ability of microscopic creatures to build shells and exoskeletons

14. © 2014 Pearson Education, Inc. The Oceans Characteristics of ocean waters (cont.) –Temperature Decreases with increasing latitude Ranges from near 80 ° F to near 28 ° F –Density High temperature means low density High salinity means high density

15. © 2014 Pearson Education, Inc. Movement of Ocean Waters Three primary groupings: tides, currents, and waves Tides –Bulges in sea surface in some places that are compensated by sinks in the surface at other places –Significant in shallow water areas for horizontal placement of water Causes of tides –Gravitational attraction of Moon (lunar tides) and Sun (solar tides) –More gravitational force on the side of Earth facing the Moon –More centripetal force on opposite side to keep Earth in orbit –Two bulges form on opposite sides of planet

16. © 2014 Pearson Education, Inc. Movement of Ocean Waters Causes of tides (cont.) –Two tidal cycles in 25 hours –Flood tide and high tide –Ebb tide and low tide Monthly tidal cycles –Tidal range – difference in high and low tides –spring tides –neap tides Global range of tides

17. © 2014 Pearson Education, Inc. Movement of Ocean Waters Currents –Subtropical gyres develop from surface wind patterns –Deep ocean circulations Result from differences in salinity and temperature in deep ocean water Thermohaline circulation Water in northern latitudes is colder and higher salinity, so it sinks –Global conveyer-belt circulation Waves –Minor disturbances to sea surface

18. © 2014 Pearson Education, Inc. Permanent Ice—The Cryosphere Cryosphere –Second greatest storage of Earth’s water –Two groups; ice on land and ice in water –Approximately 10% of Earth’s surface is ice –Different names Ice pack Ice shelf Ice floe Iceberg

19. © 2014 Pearson Education, Inc. Permanent Ice—The Cryosphere Cryosphere (cont.) –Largest ice pack covers most of the Arctic ocean surface –Several large ice shelves attached to Antarctica –Large ice floes form off of Antarctica Permafrost –Permanently frozen ground ice –Recent issues related to the thawing of permafrost

20. © 2014 Pearson Education, Inc. Surface Waters Represent only 0.02% of the world’s total moisture Numerous surface water types Lakes – bodies of water surrounded by land –Small lakes are called ponds –Lake Baykal in Siberia is largest lake by volume

21. © 2014 Pearson Education, Inc. Surface Waters Lakes (cont.) –Saline versus freshwater lakes –Ephemeral lakes (only contain water sporadically) –Two conditions required for lake formation Natural basin with restricted outlet Sufficient water to keep basin filled –Most are relatively short- lived

22. © 2014 Pearson Education, Inc. Surface Waters Human alteration of natural lakes –Irrigation –Water diversion projects –Reservoirs Artificial lakes used for hydroelectric power, municipal water, and stable agriculture

23. © 2014 Pearson Education, Inc. Surface Waters Swamps and Marshes –Flattish places that are periodically submerged and shallow enough to permit plant growth –Swamps grow trees –Marshes grow grasses and rushes Rivers and Streams –Streams smaller than rivers –Geographers call all running water streams –Allow for drainage of land surface water toward oceans –Drainage basins

24. © 2014 Pearson Education, Inc. Surface Waters Drainage basins for major rivers of the world

25. © 2014 Pearson Education, Inc. Groundwater Water beneath land surface world-wide More than half found within 800 meters of the surface Precipitation or water basins are the sources Quantity held depends on –Porosity –Permeability Aquifers and aquicludes

26. © 2014 Pearson Education, Inc. Groundwater Zone of aeration –Topmost band in underground water supply –Water amount fluctuates rapidly with time Zone of saturation –All pore spaces filled with water, called groundwater –Top of the zone is the water table –Water table intersects surface, water flows out (lakes, swamps, etc.) –Well water drawn faster than replenished creates a cone of depression –Lower limit has absence of pore spaces

27. © 2014 Pearson Education, Inc. Groundwater Zone of confined water –Zone that exists in some regions that is below the region of impermeable rock below the zone of saturation –Pressure at the great depth of the water will cause water to rise to piezometric surface –Artesian well versus sub- artesian

28. © 2014 Pearson Education, Inc. Groundwater Waterless zone –Pressure too great to sustain water Groundwater mining –Accumulation of groundwater is slow, but human use is rapid –The Ogallala Aquifer Water table drops with increased use Numerous wells tapped Unsustainable situation

29. © 2014 Pearson Education, Inc. Groundwater Changes to the Ogallala Aquifer

30. © 2014 Pearson Education, Inc. Summary Most of the water on the planet exists in the oceans. The hydrologic cycle describes the transition of water from land to sea to air. Ocean water has numerous defining characteristics. Ocean water movement is affected by gravitational pull from celestial objects (tides). Ocean water moves through currents based on salinity and temperature Winds and ocean surface disturbances result in waves on the ocean surface.

31. © 2014 Pearson Education, Inc. Summary Swamps and marshes exist in areas that are shallow and can support plant life. Rivers and streams help distribute water back to the oceans and replenish lakes. Underground water exists due to water basin seeping or precipitation. Human interactions in above ground and below ground water areas have drastically altered the hydrosphere.