Soil and Water Notes 1:
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The document discusses several key topics related to water and the lithosphere: 1) Weathering and erosion break down and transport rocks and sediments, forming landforms over time. Mechanical and chemical weathering break rocks into smaller pieces, while erosion transports sediment. 2) Ocean water dissolves and carries minerals, impacting the chemistry of seawater and ocean floor sediments. Water also circulates between oceans, atmosphere, and lithosphere via the water cycle. 3) Factors like climate, rock type, and topography influence the rate of weathering and types of landforms that form over thousands or millions of years. Examples are provided of distinctive landforms shaped by weathering and erosion.
Soil and Water Notes 1:
- 1. Soil & Water 1 “Energy in Water” Seamon
- 2. D I S T R I B U T I O N • 70 % of Earth’s surface is water • 4 bya water vapor condensed into shallows • 1 big ocean, 5 major basins • Pacific • Atlantic • Indian • Arctic • Southern 2VIDEO How Big is the Ocean? (5:30)
- 3. FOLLOW THE ENERGY… Energy in Oceans
- 4. C H E M I S T R Y • Water is a solvent- it dissolves solutes of solids, liquids & gases • Solute- substance that dissolves • Solution- mixture of solvent and solute http://www.chem4kids.com/files/matter_ solution.html 4 CC Video: liquids (9 min)
- 5. • Salt: halite = 85% dissolved solids in ocean • Salinity: measure of the amount of dissolved salts in a liquid WHY IS THE OCEAN SALTY? halite 5
- 6. SALT ENTERS THE OCEAN: • Chemical weathering of minerals from land into oceans • Volcanic eruptions • Chemical reactions between new sea floor & ocean water WATER IS CONSTANTLY BEING EVAPORATED, BUT SALTS REMAIN 3.6% 6 VIDEO: Why is the Ocean Salty? (1 min)
- 7. T E M P E R A T U R E • Varies with depth & location • Affected by solar energy http://www.onr.navy.mil/focus/ocean/water/temp3.htm DEPTH 7
- 8. Can sea water freeze? • Sea water can only freeze when it condenses such that it pushes out the salts first to make solid H O (28.4˚F) • floating ice insulates water below it, preventing it all from freezing 2 http://www.acecrc.sipex.aq/access/page/index.html%3Fpage=78.html http://science.kennesaw.edu/~jdirnber/oceanography/L ecuturesOceanogr/LecOceanStructure/LecStructure.html SALT WATER 8
- 9. LOCATION- Oceans are warmer near equatorial latitudes SURFACE WATER: 9
- 10. TIME OF YEAR- seasons • When the Northern Hemisphere faces away from the sun for Winter months, those oceans are cooler • When N. Hemisphere points towards the sun for Summer, those oceans are hotter http://www.abc.net.au/science/articles/2011/01/20/3116529.htm 10 SUMMER in N Hemisphere WINTER in N Hemisphere
- 11. DEPTH: Oceans get colder as you go deeper 1. Surface zone- top up to 300m, warmer and so less dense= difficult mixing with cooler waters below 2. Thermocline- 300-700m, temperature drops faster here with depth; colder water is more dense; holds more dissolved gases, slower currents 3. Deep zone- 700m +, cold, slowest currents TEMPERATURE ZONES 11
- 12. G L O B A L T H E R M O S T A T Oceans create climate! Ocean water and air temperature are always trying to reach equilibrium (same temp)… … But it never happens due to earth’s tilt & revolution AIR Temp WATER Temp AIR CHANGES TEMPERATURE FASTER THAN WATER12
- 13. • During summer months, ocean water absorbs solar energy from the atmosphere, trying to reach equilibrium with the hot air • Before equilibrium can be reached, seasons change- air cools for autumn WARM WaterCOLD Water COLD AirWARM Air Solar Energy SUMMER WINTER 13
- 14. • When air changes to cooler, winter temperatures, oceans start to release their stored warmth to now calibrate with the cooler air temperatures: WARM OCEAN BREEZES IN THE WINTER… • The opposite is true for Summer months: Air heats up, now oceans must absorb solar radiation to try and reach warmer equilibrium with the hot summer air: COOLER OCEAN BREEZES IN THE SUMMER… 14 nice vacation spot! nice vacation spot!
- 16. O C E A N C U R R E N T S Current: movement of ocean water that follows a regular pattern http://paraglidinginfo.com/2014/03/03/how-the-sun-water-and-mountains-affect-wind-patterns/ 16
- 17. Surface Current Wind Driven Deep Ocean Current Density Driven
- 19. Surface current: horizontal movements near surface, caused by wind • solar energy heats surface of the water • Global winds move the surface current • Coriolis effect: earth rotates, making water arc instead of move in a straight line • Continental deflections: currents can’t go through continents! Deep currents movement of currents deep below the surface; Form where density increases due to salinity & cold temperatures 19
- 20. Density- • how close together the molecules of a substance are or how much mass a substance has in a given space. Denser things are heavier & sink
- 21. PUTTING IT TOGETHER: THERMOHALINE Temperature: warm water moves from the equator towards the colder poles Salt density: how much salt in the water determines the density of the water; water moves from more dense to less dense areas of concentration Thermohaline- temperature and salt affect density & controls movement of currents 21
- 22. G L O B A L C O N V E Y O R B E L Thttp://www.global-greenhouse-warming.com/oceans.html 22 VIDEO: Making waves: the power of concentration gradients (5min)
- 23. Upwelling- movement of deep, cold, nutrient- rich water to the surface 23
- 24. AN EXAMPLE: El Nino local wind patterns (along South America) move local surface currents & so are replaced by deep cold water from below • Cold, nutrient rich water from deep ocean rises to surface to replace warm surface water: Iron, Nitrates • El Nino • La Nina • NOAA buoys study & predict 24
- 26. Water Cycle- 1. Energy from the sun is transferred to Earth through electromagnetic waves 2. Warm water evaporates into the atmosphere 3. The atmosphere condenses the vapor and precipitates the water back to the surface of Earth 4. Streams and rivers traverse the landscape towards points of lowest elevation, eroding & picking up minerals, becoming stored in ground water, frozen in ice, or distributed into water reservoirs 5. Streams and rivers carry water back to ocean.26
- 27. 27 Weathering: taking away of pieces of the crust in the flow of water, wind, or ice Deposition: dropping off of the sediments
- 28. • Dissolved gases enter at rivers, streams, volcanic eruptions, decay, living organisms & through the water cycle http://www.iceagenow.com/Ocean_Warming.htm 28
- 29. Effects of Temperature: • Colder water dissolve gases better • Warmer water cannot hold as many gases (remember global warming?) http://www.middleschoolchemistry.com/multimedia/chapt er5/lesson6 29
- 30. • Carbon sink: ecosystem that absorbs more carbon than it lets out- • oceans can hold carbon in the form of CO2 for thousands of years 30
- 31. Ocean chemistry is currently changing at an unprecedented rate. 31
- 32. FOLLOW THE ENERGY… Water & the Lithosphere
- 33. Destructive Force: takes away crust • Weathering- break down of rocks • Erosion- carrying away of the pieces of rock by wind, moving water, ice, and gravity • most erosion on Earth is done by water Constructive Force: building up of new crust • deposition- dropping off of the eroded pieces VIDEO: How the Grand Canyon was Formed (6 min)
- 34. TYPES OF WEATHERING • mechanical weathering- rocks are broken down into smaller pieces WITHOUT changing their composition • chemical weathering- rocks break down as minerals CHANGE in composition; become a new substance; as by acid rain
- 35. Mass Movement Rapid movement of Earth materials by gravity • Landslides- large amounts of rock suddenly break from cliff/mountain & bury homes/villages; steep slopes; arid regions after a heavy rain • Avalanches- gravity pulls down huge amounts of slow; start by vibrations • Mudflow- slopes rich in clay receive too much rain; esp where there is no vegetation • Lahar- mudflow on side of a composite volcano; ash mixes with snow/ice forming hot- fast moving mud
- 37. Soil Creep VERY slow downward progression of rock and soil down a low grade slope; water, temperature change & gravity
- 38. MECHANICAL WEATHERING Ice wedging/frost action • water enters small cracks in the rock • When water freezes, it expands, forcing the crack to widen • process repeats until rock breaks apart
- 40. MECHANICAL WEATHERING Wetting & Drying • breaks up rocks that are made from clay • When wet, clay expands; shrinks when dry • process repeats until rock breaks apart
- 42. MECHANICAL WEATHERING Exfoliation • soil and rock is removed (glaciers or uplifting), exposes rock found deep underground • This releases pressure causing surface of rock to expand & crack
- 44. MECHANICAL WEATHERING Plant Roots • Deep roots of trees break apart rocks
- 45. Glaciers: Erosion: Glaciers carry rock particles to lower elevations Deposition: Melting glaciers deposit boulders & sediments called moraines MECHANICAL WEATHERING
- 46. CHEMICAL WEATHERING Hydrolisis • water (hydro) reacts with minerals such as feldspare and form clay
- 47. CHEMICAL WEATHERING Oxidation • oxygen reacts with some minerals (esp iron) to form rust • occurs faster with water
- 50. CHEMICAL WEATHERING Carbonic acid • carbon dioxide dissolves in water to form this acid • can cause minerals to dissolve, especially those containing calcite (remember the seashells & ocean acidification?)
- 52. CHEMICAL WEATHERING Lichen & Fungi • These organisms decompose organic material & chemically weather the rock
- 53. Factors that Affect Rates of Weathering: • Hardness- rock’s resistance to weathering • climate- • chemical weathering happens faster in warm, wet climates • mechanical weathering happens faster in cold, dry climates • Surface area- more surface area… more weathering
- 55. Death Valley, CA
- 56. Great Sand Dunes NP, Colorado Great Sand Dunes NP Formation (5 min)
- 57. The central area of rock was less resistant to weathering… thus the ‘arch’ was formed! VIDEO Arches Formation (3 min)
- 58. Antelope Canyon, Arizona VIDEO: How Antelope Canyon Formed (3 min)
- 59. Bryce Canyon, Utah VIDEO: Bryce Canyon & Zion formation (3 min)
- 61. Carlsbad Caverns, NM Carlsbad Caverns Formation (5 min)
- 63. Badlands, South Dakota VIDEO Bad Lands formation (3 min)
- 64. VIDEO: Giant’s Causeway 2 min Giant’s Causeway, Ireland