Miss Hayungs 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. As temperature increases, pressure increases As temperature decreases, pressure decreases As pressure increases, density decreases As pressure decreases, density increases T T The P P D D key is to remember how the molecules move in relation to the temperature and what that means for density 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. 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. 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. 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) 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) 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) 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 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 Divergent boundary of oceanic crust Convergent boundary of oceanic and continental crust 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 Transform boundary 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… Primary waves (P-waves) Compression Move through any material and arrive at seism,ic station first Secondary Lateral motion Slower than p-waves and only move through solids Surface waves (S-waves) waves (L-waves) Only sensed at surface 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!) The cycling of rock between three types of material: Igneous rock – formed from cooling of magma Sedimentary rock – formed from weathering, erosion, deposition, burial, lithification Intrusive/extrusive classification based on where it forms Felsic/intermediate/mafic/ultramafic classification based on mineral composition of rock 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) 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 Topsoil Zone of eluviation and leaching Subsoil R horizon Agricultural No-till farming or low-till farming Terracing or contour farming Trees as wind breaks Case methods Studies 1930s Dust Bowl in the plains states 1935 Soil Conservation Act 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) 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 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. 78% Nitrogen 21% Oxygen 0-4% H2O(g) The other 1% is all other elements (Ex.: Ar, CO2, Ne, He, CH4, H2, O3, etc.) 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 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 – stratosphere mi – mesosphere Contains some ice-crystal clouds; temperature decreases with height in this layer; this is the coldest layer of atmosphere. Mesopause comes next 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. 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 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) 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 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 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 Cold front forcing warm, moist air upward, resulting in a vertical development cloud (severe t’storm) Warm front moving into area, gradually lifting and causing cirrus clouds to form. Station Models Shows the current weather for a specific site (a snapshot of weather that can be reported to news stations, ex.) 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) 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. 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. 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) 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. Milankovitch Variations Sunspot A 22-year cycle of min & max # of sunspots Volcanic eruptions Cause general cooling of Earth due to particulates blocking sun’s rays El cycles 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 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 diseasecarrying 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) Seasons Result from Earth’s axis being tilted to its orbital plane at an angle of approx. 23.5 degrees and 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. Yellowstone Hotspot Coastal Vulnerability to Rising Sea Levels Coastal Vulnerability to Hurricanes El Nino and Landslides Miller, G T. Living In the Environment. 13th ed. 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. 2nd ed. USA: Research and Education Association, 2008. Print. Created using MLA Citation Maker on www.oslis.org.