APES Review: Earth Systems and Global Changes

1. APES Review:Earth Systems and Global Changes Miss Hayungs

2. Properties that drive global processes • Remember some key scientific concepts: • The relationship between Temperature, Pressure, and Density (relates to convection) • Convection, Conduction, and Radiation (transfer of heat or heat energy) • These are all factors in remembering movement in the atmosphere, oceans, mantle, etc.

3. T P D • As temperature increases, pressure increases • As temperature decreases, pressure decreases • As pressure increases, density decreases • As pressure decreases, density increases • T P D • T P D • The key is to remember how the molecules move in relation to the temperature and what that means for density

4. convection • Energy is moved by energy-containing particles from one place to another (primary in the atmosphere, oceans, and within Earth) • This is the circulation of material that occurs when the density of material is decreased due to warming or increased due to cooling. The movement of matter here forms a convection current due to the rising of less dense matter and sinking of the cooler matter.

5. Convection • Convection in the mantle is the mechanism for plate movements. • Convection in the atmosphere is responsible for global winds (think back to Hadley, Ferrel and Polar cells), formation of some clouds, high and low pressure systems, and ultimately for various climates and biomes. • Convection in the oceans helps to move cold and warm water currents around the globe and adds to pressure differences. (thermohaline circulation involves differences in temp and salinity) • Convection moves heat that comes from the sun and distributes it around the globe.

6. Conduction • Energy transferred from one particle to another through a collision between the two particles. • When this happens some heat is produced. • Example: The molecules in the pot of water heat up because the pot is touching the burner.

7. Radiation • Energy carried by a photon from one place to another • Radiation is energy that comes from a source and travels through some material or through space. Light, heat and sound are types of radiation. • Ionizing radiation can produce ions in matter. • (Ex…the more damaging end of the EM spectrum)

8. Properties of water • Weather is affected by convection, conduction and radiation, but also properties of water such as: • Specific heat (moderation of temperature fluctuations along coastal areas or near large bodies of water) • Energy of vaporization (evaporative cooling) (latent heat) (Ex. Evaporation of water – holds or stores a lot of energy for use in hurricane)

9. Lithosphere– plate tectonics • Theory of Continental Drift • Alfred Wegener proposed that all of the continents were once joined together (matching coastlines, fossil correlations) • This was rejected by the scientific community because he had no explanation for how/why the continents moved. • Seafloor Spreading • Harry Hess compiled data from several scientists to explain his theory of seafloor spreading. (sonar used to map the topography, magnetic readings of rock, sediment data, isochron maps of seafloor)

10. Plate tectonics • Using all of the data compiled over the decades from several scientists, the Theory of Plate Tectonics was developed. • Types of crust • Continental and Oceanic • Plate Boundaries - • Divergent boundaries • Convergent boundaries • Transform boundaries

12. Boundaries • Divergent • Plates move away from each other • Oceanic-Oceanic divergence= new crust formed at oceanic ridge • Continental-Continental= new crust formed at rift valleys • Ex- Mid-Atlantic Ridge and African Rift • Convergent • Plates move toward each other; oceanic plate will subduct • Continental-Continental convergence= no subduction; plates will buckle – forms tall, folded mountains • Ex. Himalayas

13. Convergent boundary of oceanic and continental crust Divergent boundary of oceanic crust

14. Oceanic-Oceanic=one plate subducts, forming a trench; the subducted plate will be melted/recycled; volcanic islands are formed • Ex. Mariana trench and Japan • Oceanic-Continental=oceanic plate subducts, forming a trench at the subduction zone; volcanic mountain range forms on continent • Peru-Chile trench and Andes Mountains • Transform • Plates slide past each other. • No new crust formed, no recycling of crust • Ex. San Andreas fault

15. Transform boundary

16. Earthquakes • Plate boundaries are seismically active and prone to earthquakes. • When the plates move, there is friction between the plates, eventually the plates will “give”, and there is a release of kinetic energy. • Where the rocks “give” is the focus. • Directly above the focus at the surface is the epicenter. • Seismic waves radiate outward from the focus – three types…

17. Seismic Waves • Primary waves (P-waves) • Compression • Move through any material and arrive at seism,ic station first • Secondary waves (S-waves) • Lateral motion • Slower than p-waves and only move through solids • Surface waves (L-waves) • Only sensed at surface

18. Earthquakes • Three seismic stations are needed to triangulate where the focus occurred • The Richter Scale • Logarithmic scale that measures the intensity of the earthquake. • For every increase in whole number on the Richter scale, there is a ten-fold increase in ground displacement and 30-fold increase in energy released. • (Ex. 1960 Chile earthquake measured a 9.5!)

19. Rock Cycle • The cycling of rock between three types of material: • Igneous rock – formed from cooling of magma • Intrusive/extrusive classification based on where it forms • Felsic/intermediate/mafic/ultramafic classification based on mineral composition of rock • Sedimentary rock – formed from weathering, erosion, deposition, burial, lithification • Clastic/organic/chemical classification based on how it forms • Clastic sedimentary rock is further classified by grain size • Metamorphic rock – formed by exposure to heat and pressure • Foliated/non-foliated classification based on presence of lines or lack of lines seen in rock (texture)

20. Igneous rock

21. Soil • Soil forms from the weathering of rock. It can take hundreds to thousands of years to create a deep soil. • Soil composition depends on the minerals in the parent rock. Nutrients come from these minerals and the organic material that will decompose and become part of the nutrient load. • Soil profiles (cross-section of horizons) • Will vary by biome due to amount and type of weathering as well as amount of precipitation

22. Soil horizons within a profile Topsoil Zone of eluviation and leaching Subsoil R horizon

23. Soil conservation • Agricultural methods • No-till farming or low-till farming • Terracing or contour farming • Trees as wind breaks • Case Studies • 1930s Dust Bowl in the plains states • 1935 Soil Conservation Act

24. Hydrosphere – The Ocean • Ocean currents • Help to disperse heat from the sun around the globe • Ocean currents caused by: • Wind (surface currents) • Differences in salinity and temperature (density currents or deep water currents)

25. Ocean • Tides • Caused by the gravitational pull of the sun and moon • Remember the tidal range and the adaptations of the organisms in the intertidal zone

26. Atmosphere • Origin – remember the Miller and Urey experiment • Evolution - Primitive Earth’s atmosphere was very different in the first few hundred million years (probably hydrogen and helium) and only changed as comets, volcanoes, and other sources of elements entered the picture.

27. Composition of the atmosphere • 78% Nitrogen • 21% Oxygen • 0-4% H2O(g) • The other 1% is all other elements (Ex.: Ar, CO2, Ne, He, CH4, H2, O3, etc.)

28. Layers of the atmosphere • 0-7 mi above surface – troposphere • Most of Earth’s weather happens here; 75% of the atmosphere’s mass is in this layer; temperature decreases with height. The tropopause is the transitional layer between troposphere and stratosphere • 13-30 mi – stratosphere • Most jet travel happens here; the protective ozone layer causes the temp to increase with height in this layer (ozone layer aborbs some ionizing radiation) The stratopause is the transitional layer before the mesosphere • 31-50 mi – mesosphere • Contains some ice-crystal clouds; temperature decreases with height in this layer; this is the coldest layer of atmosphere. Mesopause comes next

29. Layers of the atmosphere • 52-300 mi – thermosphere • Includes the Ionosphere • Aurorae; meteors burn up in this layer; temperature increases with height due to X-rays, gamma rays, and ultraviolet radiation from the sun • 300-6000 mi – exosphere • This is the transitional layer that leads you to outer space. The atmosphere slowly decreases in density until you are into interstellar space. H and He exist in this layer.

30. Weather • Temperature, pressure, moisture, global wind patterns (and correlating Coriolis Effect), latitude, natural cycles of the solar system all come in to play in weather. • Global winds caused by convection currents. • Tradewinds, prevailing westerlies, and polar easterlies • These winds also help to distribute solar heat around the globe. • Hadley, Ferrell, and Polar cells

31. Clouds • Clouds form when you have warm, moist air rise and condense • The mechanism that causes the rise may vary • Density difference (cold sinks, warm rises) • fronts • Mountains (air forced upward over a mountain top is called orographic lifting)

32. Cloud names • Clouds are named by their appearance and altitude • Cumulus means “heap” • Stratus means “layer” • Cirrus means “curl of hair” or “whispy” • Nimbus means “rain” • “Cirro-” refers to a high level cloud (made of ice crystals) • “Alto” refers to a mid-level cloud • Low-level do not necessarily have a prefix • Ex. Altocumulus clouds are mid-level clouds that look puffy and billowy

33. Weather fronts • Cold front – a cold air mass that comes in at ground-level (cold, dense air) • Warm front – a warm air mass that moves into an area (warm air is less dense, so it “wedges” over the cooler air in front of it) • Occluded front – Cold air mass overtakes the warm air mass in front of it, wedging the warm air upward and between the two colder air masses • Stationary front – two fronts moving in opposing directions meet and neither advances

34. Associated weather • Cold front – warm moist air lifted quickly upward, so there can be large, powerful thunderstorms (some with hail) • Warm front – cirrus clouds come in first, then a steady drizzle can happen. More gradual weather change than we see with a cold front

35. Cold front forcing warm, moist air upward, resulting in a vertical development cloud (severe t’storm)

36. Warm front moving into area, gradually lifting and causing cirrus clouds to form.

38. Station Models Shows the current weather for a specific site (a snapshot of weather that can be reported to news stations, ex.)

39. Severe weather • Hurricane – cyclonic, low pressure system that is fueled by the warm ocean waters. It forms off the coast of Africa and builds in strength as it moves west in band of trade winds. As it hits land (N. America) it moves east due to our prevailing global winds, loses strength and “dies out” over cooler ocean waters or land. (Saffir Simpson scale) • Tornado – cyclonic, low pressure system that is formed because of the turbulence and wind shear associated with severe thunderstorms. (Enhanced Fujita scale)

40. Climate • Weather is the short-term variation in atmospheric conditions. • Climate is a long-term variation in the atmospheric condition (an accumulation of at least 30 years’ worth of data) • There are natural and anthropogenic causes to the changes in Earth’s changing climate.

41. Milankovitch Cycles • The collective effect of changes in Earth’s movements upon its climate • Earth's perihelion and aphelion -Earth is closest to the Sun (perihelion) in early January and farthest (aphelion) in early July. -The relation between perihelion, aphelion and the Earth's seasons changes over a 21,000 year cycle.

42. Axial tilt, precession and eccentricity of Earth's orbit vary in several patterns, resulting in 100,000-year ice age cycles over the last few million years. • The Earth's axis completes one full cycle of precession approximately every 26,000 years. -Precession refers to the movement of the rotational axis of a body (like a spinning top as it wobbles)

43. The eccentricity of Earth’s orbit is currently about 0.0167. (how far from circular the orbit is) • Over thousands of years, the eccentricity of the Earth's orbit varies from nearly 0.0034 to almost 0.058 as a result of gravitational attractions between the planets. • The elliptical orbit rotates, more slowly, leading to a 21,000-year cycle between the seasons and the orbit. • The angle between Earth's rotational axis and the normal to the plane of its orbit moves from 22.1 degrees to 24.5 degrees and back again on a 41,000-year cycle. • Currently, this angle is 23.44 degrees and is decreasing.

44. Milankovitch Variations

45. Other natural events • Sunspot cycles • A 22-year cycle of min & max # of sunspots • Volcanic eruptions • Cause general cooling of Earth due to particulates blocking sun’s rays • El Nino Southern Oscillation (ENSO) • Also in a cycle that affects coastal AND inland regions; can greatly change that year’s precip/temp/storm amounts • Greenhouse Effect (Enhanced) • Greenhouse effect makes conditions conducive to life on Earth (amt of greenhouse gases) • Too much of a “good thing” causes increased heating

46. Effects of climate change • Reduction in sea ice and change in albedo • Decrease in seasonal ice melt to local watersheds • Higher ocean levels that may flood coastal population centers • Spread the range of disease-carrying vectors that are indigenous to warmer climates • Extinction rates will increase when the natural evolution and co-evolution (re: adaptations) cannot keep up with a shift in biotic/abiotic factors • Biodiversity of coral reefs will decrease as ocean temps increase, causing bleaching • Methane hydrate released into atmosphere from melting permafrost (greenhouse gas) as well as damage to structures already in place in those regions • Warmer oceans will allow for increased rates of evaporation, giving more energy to storms (increased storm intensity or more incidences)

47. Seasons

48. Seasons • Result from Earth’s axis being tilted to its orbital plane at an angle of approx. 23.5 degreesand Earth’s position in its orbit. • At any given time during summer or winter, one part of the planet is more directly exposed to the rays of the Sun (more direct sun rays = summer) • Aphelion in summer/perihelion in winter for N hemisphere • This exposure alternates as the Earth revolves in its orbit. • N and S hemispheres experience opposite seasons.

49. Case Studies • Yellowstone Hotspot • Coastal Vulnerability to Rising Sea Levels • Coastal Vulnerability to Hurricanes • El Nino and Landslides

50. Citations Miller, G T. Living In the Environment. 13thed. Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning, 2004. Print. Oak Ridge National Laboratory. Web. 20 Apr. 2014. <http://orise.orau.gov/reacts/guide/define.htm>. Reel, Kevin R. AP Environmental Science. 2nded. USA: Research and Education Association, 2008. Print. • Created using MLA Citation Maker on www.oslis.org.