ISCI 101 Final Exam Study Guide PDF

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1 ISCI 101 Final Exam Study Guide

Chapter 17: Plate Tectonics 

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Great Idea o The entire earth is still changing, due to the slow convection of soft, hot rocks deep within the planet The Dynamic Earth  Slopes and Peaks in Young and Older Mountains  Eroded (Appalachian Mountains – 400 million years old)  Jagged and Pointy (Rocky Mountains – 65 million years old) o The Case of the Disappearing Mountains  Erosion by water and air  Few hundred million years (Earth is 4.5 billion years old)  Mountains continually forming  Earth’s surface is NOT STATIC  Mountains form and erode continuously o The Dynamic Earth  Small-scale changes  Construction sit o Erosion by rain  Large- Scale Changes  Volcanoes  Earthquakes  Erosion o Volcanoes and Earthquakes: Evidence of Earth’s Inner Forces  Earths inner forces result in tectonic activities’  Volcano o Magma breaks through surface  Can be quick (explosion)  Can be slow (stately surface flow of molten rock – lava) o EX: Mount St. Helens o Cross-section  Volcano  volcanic pipe  magma  Earthquake o Rock break along fault (a more or less flat surface) o Energy transmitted as seismic wave (or sound wave)  Building elastic potential energy snaps into violent kinetic energy o Richter Scale: the amount of ground motion that would be measured by an instrument at a fixed distance from the center of the earthquake

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Not used anymore – similar magnitude scale based on energy released is used today  1 Richter higher = 10X ground motion  7 will have 100 times the motion than a 5  Magnitude Scale:  5 will be felt by most people, but do little damage in areas with well-constructed buildings  6/7 will do considerable damage to buildings  8 will level large areas o Occurs on faults  EX: VA earthquake o Tsunami occurs as a result of tectonic activity (like an Earthquake) in the ocean The Movement of the Continents  Francis Bacon  Continents fit like a puzzle  Had no explanation for why though  Alfred Wegener  Continental drift  continents are in motion  An idea that continents are not fixed  Current Evidence  Ocean Floors o Mapping of floor after WWII –> scientists discovered ocean floor wasn’t flat plains like originally thought  Ocean floor dynamic and changing  Canyons, mountains  Mid-Atlantic Ridge = longest mountain range on Earth o Similar ridges are sites of continuous geological activity  earthquakes, volcanoes, lava flows  Magnetic Reversals o Earth’s Magnetic Field  Earth has magnetic field with north and south magnetic poles  Changes direction periodically (approx. every 7000 years) o Magnetite  Iron oxides – bits of iron  Crystals in lava align to magnetic field of the Earth  When in fluid state, align themselves in a northsouth direction parallel to Earth’s magnetic field

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When it hardens, bits of magnetite frozen in place = memory of where the magnetic north pole was when it solidified o Paleomagnetism – study of the record of Earth’s magnetic field in rocks o Seafloor spreading – ocean floor is getting wider as new molten rock comes from deep within Earth  New rock comes to surface  Magnetic strips that are parallel to ocean ridges  Rock Ages o Radioactive isotopes  Can be used to measure how long ago they erupted  Rocks near Mid-Atlantic Ridge = younger  Rocks farther away = older  New Support for the Theory o Radio astronomy o Discovered Europe is separating from North America at a rate of 5 centimeters a year o Science by the Numbers  The age of the Atlantic Ocean  Atlantic ocean began to open 140 million years ago  Pangea = North America + South America + Eurasia + Africa  Not Atlantic Ocean during Pangea  Continents will continue to move as seafloor spreads Plate Tectonics: A Unifying View of the Earth  Theory of Plate Tectonics: model of the dynamic Earth, emerged from studies of the Ocean floor, Paleomagnetism, rock dating, etc  Tectonic plates – large pieces that Earth’s surface is broken up into  Plates are:  Rigid, moving sheet of rock  Crust and part of the upper Mantle  Continental o 100 km (60 miles) thick o Lower density (granite) o Caps oceanic plates  Oceanic o 8-10km thick o Dense rock (basalt) on top of mantle rock  Earth’s surface  ¼ continent  ¾ water  Tectonic plate boundaries are not the same as continental and oceanic boundaries

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Constant motion of underlying plates is fundamental to understanding Earth’s dynamics The Convecting Mantle  The plates move on the mantle due to forces generated by Mantle convection  Mantle Convection  Motions driven by Earth’s interior heat energy  Sources contributing to Earth’s interior heat  Gravitation potential energy o Left over from the great bombardment and differentiation of the mantle and core as Earth formed  Decay of radioactive elements o Uranium and other radioactive elements are common throughout Earth’s core and mantle o Decay over time and produce energetic/fast-moving products that collide with atoms and molecules in surrounding rocks and give up their energy as heat  Deep inside Earth, all this heat softens rocks to the point that they can flow slowly (like hot taffy)  Movement  Heat moves to cooler regions  Convection cells in mantle  Very slow o 200 million years for one cycle Plate Boundaries  Divergent Boundaries  Characteristics o Occurs when plates lie above a zone where magma comes to surface  Volcanoes  Chain of mountains o Earthquakes  Oceans form from this o seafloor spreading  plates pushed apart = Mid Atlantic Ridge o Hydrothermal vents on and around mid-oceanic ridges  Convergent Plate Boundaries  Most convergent plate boundaries sink beneath another to form a SUBDUCTION ZONE o When plate is sub ducted, it rejoins mantle material from which it came  Types o Oceanic-Oceanic  Near the volcanic coast of Philippines  Subduction Zone

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If no continents are on leading edge of 2 converging plates, deep ocean trench will form  Deep oceanic trench – Marian’s trench o Continental-Continental  The Himalayas, Ural Mountains (mark point when Europe and Asia were welded together), Alps (mark point when Italian Peninsula was joined to Europe)  High, Jagged Mountain Chain o Continental-Oceanic  Denser ocean plate will subduct under continent  Deep oceanic trench may form  Example  The Andes Mountains of South America  Cascade Mountains of Northwestern United States  Transform Plate Boundary  Two plates move past each other o No new plate material being produced  San Andreas fault in California o NOT smooth o Earthquakes as a result of movement  Review of Plate Boundary Processes  Divergent o Volcanoes o Earthquakes  Convergent o Volcanoes o Earthquakes  Transform o Earthquakes The Geological History of North America  Northeastern Canada and Greenland  Several billions of years old (oldest area of North America)  Western US  Terranes = masses of rock several hundred kilometers across o Added to continent over time  Were originally large islands in Pacific Ocean that were carried to North American by plate activity o Wichita, KS used to be a coastal area  Appalachian Mountains  Formed 450-300 million years ago  Continental-Continental convergence zone  US Mountains  Appalachian Mountains – oldest mountains

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Rocky Mountains – formed 60 million years ago o Warping, folding and fracturing of continent  The Colorado Plateau o Gentle uplift  Sierra Nevada – youngest mountain range o Molten rock pushed up sediments  Plate Boundaries Processes Another Look At Volcanoes and Earthquakes  Plates and Volcanism  Common along divergent plate boundaries  Common near convergent plate boundaries o Except when 2 continental plates collide o Subduction zones causes this  Direct consequence = “Ring of Fire” – string of volcanoes that borders the Pacific Ocean  Common above hotspots o Hotspots  dramatic type of volcanism indirectly associated with plate tectonics  Hawaii, Yellowstone Park, Iceland  Mantle Plumes – large, isolated chimney-like columns of ascending hot rock o Sources of hot spots are stationary,  plates move over source = chain of volcanoes form  Earthquakes o Release of stress built up in rocks  Stress builds for several reasons  Heated rock expands and cools  Changes in pressure  Two tectonic plates move past each other at transform plate boundaries o At plate boundaries or elsewhere  Volcanoes o Form above a subduction zone o Ring of Fire o The Hawaiian Islands  Kauai is the oldest  Seismology: Exploring Earth’s Interior with Earthquakes  Seismology o Study of sound vibrations within Earth o Used to determine Earth’s inner structure o Earthquake predictions  Compressional or longitudinal – similar to sound o Molecules move back and forth same direction as the wave

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Transverse or shear waves – similar to water waves (molecules move up and down perpendicular to the direction of the wave)

Chapter 18: Earth’s Many Cycles  

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Great Idea o All matter above and beneath Earth’s surface moves in cycles Cycles Small and Large o Recycling  Where did the aluminum go?  Aluminum atom will last virtually forever  Recycling saves energy o The Nature of Earth’s Cycle  3 great cycles of Earth’s materials  The oceans (water cycle)  The Atmosphere (air cycle)  Rocks  2 central ideas of the movement of matter  Earth’s materials move in cycles  A change in one cycle affects the others  Atoms constantly moving and (re)cycling  Reservoirs  Hydrologic cycle  Atmosphere cycle  Rock cycle  Many of the cycles are driven by the tendency of heat to spread out  Hot  cold  Sources of heat energy o Sun o Geothermal processes The Hydrologic Cycle o Reservoirs of Water  Amount of water on earth is fixed (conservation of mass)  Major repositories  Ice Caps: layers of ice that form at Earth’s north and south polar regions  Glaciers: large bodies of ice that slowly flow down a slope or valley under the influence of gravity o 96% found in Antarctica and Greenland  Iceberg: a large piece of freshwater ice that has broken off a glacier and is floating freely in open water  Unseen reservoirs  Ground water o Aquifers: underground reservoirs of water

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Major Repositories of Water  Oceans – 96.5% of Earth’s supply  Lakes, rivers, and streams -- .013%  Ice Caps and Glaciers – 1.74%  Groundwater – 1.7%  Clouds, atmosphere -- .001%  Living things -- .0001% Movements of Water Between Reservoirs  Constant motion both within and between reservoirs  Hydrologic cycle involves o Short-term back and forth transfer of water between ocean and land o Most terrestrial life depends on this cycle  Ocean Currents – rivers of moving water within the larger ocean o More static movement of earth’s water o Redistribute heart across planet  help determine climate o 5 MAJOR gyres  The Science of Life o Facts about Earth’s Water  96% salty  Less than 1% readily available for human use  Agriculture, industry and personal needs result in an average daily water consumption of more than 2,000 gallons per person in North America Chemical Cycles in the Oceans  Chemicals in constant motion  Saltiness or salinity o Constant over several hundred million years o Primarily determined by Na+ and Cl- ions  Other elements dissolved in oceans as well o Residence time: average time that an atom will stay in ocean water before it is removed by chemical reactions  Residence times for Elements in Ocean  Na+ = 260 million years  Cl- = for ever  Calcium = 8 million years  Gold = .042 million years  Potassium = 11 million years  Copper = .05 million years o Chemical Cycle occurring in ocean  Dry salt deposits (Great Salt Lake in Utah) occur when a body of salt water evaporates o Only way to remove chlorine from water  The Science of Life

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Element resident times in the human body  Human body recycles Ca, Fe, C , O, N continuously  Lead, mercury do not recycle fast  Have high residence times

Ice Ages  Ice Age o Water locked in glaciers o Glaciers advance from poles across land  Currently in an ice age o Within current ice age, we are in an Interglacial period  Earth’s total water is fixed o Ice caps, glaciers grow o Sea level drops The Atmospheric Cycle o Redistribute heat across the surface of the planet o Air Masses: Reservoirs of the Atmosphere  Air Mass  Uniform temperature and moisture  Adjacent air masses differ in physical properties  Weather  State of the atmosphere at any given time and place  SHORT TERM  Climate  Long-term average of weather for a given region o Weather  5 variables define state of atmosphere  Temperature o Reported daily temperature is at ground level o Temperature changes depending on altitude above ground  Air Pressure o Decreases with altitude because air is compressed by its own weight o Low-pressure  cooling and clouds o High-pressure  warmer, dryer air o Jet stream: high speed air currents  Humidity o Measure of the HIGHLY VARIABLE atmospheric water content o Nitrogen and oxygen make up 99% of dry atmosphere  Cloudiness o Closely tied to humidity o Clouds = concentration of water droplets or ice crystals  Outline the contact between 2 adjacent air masses  Prevailing Winds

10 o Consequence of atmospheric convection The General Circulation of the Atmosphere  Circulation of prevailing winds powered by Sun  Air in tropics  heated and rises  Cools and sinks  Prevailing Winds  Caused by Earth’s rotation o Common Storms and Weather Patterns  Severe Weather  Tropical storms or tropical cyclones  form over warm waters o Hurricanes = Atlantic Ocean o Typhoons = Pacific Ocean  Tornadoes: rotating air funnels o Largest tornadoes (air speeds 300 mph+) are most severe weather phenomenon known  Weather Cycle  El-Nino: coupling of atmospheric and water-cycle of the Earth o Affects weather from Pacific Basin to the Atlantic Coast o Requires both winds and ocean currents to work o Causes severe storms/flooding on western coast and droughts from Australia to India o Climate  Seldom changes over human lifetimes  Influencing factors of climate  Large bodies of water and ocean currents  Mountain ranges  Tectonic plate movement plays major role  Atmospheric cycle is strongly influence by other global cycles o Understanding Climate  Long-Term Climate  Oceans  Mountains  Sunlight o Amount radiated back to space depends on the concentration of greenhouse gases in the atmosphere  Prediction  Global circulation models  Carbon dioxide levels have raised above line The Rock Cycle  A cycle of internal and external Earth processes by which rock is created, destroyed and altered  Rock formations – bodies of rock that form as a continuous unit = reservoirs of rock cycle o Igneous Rocks – solidify from hot liquid magma o

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First solids to appear on Earth’s ancient surface Types  Volcanic or Extrusive o Solidify at surface after volcanic eruptions o Most common type of volcanic rock =basalt  Intrusive o Solidify below surface or underground  Examples: granite, pumice  Still form today Sedimentary Rocks – from grains of material worn off previous rock  Formation  Compaction  Cementation  Examples: sandstone, shale, limestone Metamorphic Rocks- formed from pressure and heat (but not enough to melt the rock)  Examples:  Slate – metamorphosed shale  Schists  Gneisses  Quartzite – metamorphosed sandstone The Story of Marble  Marble  Metamorphic rock  Process of formation  Begin as limestone  Subjected to heat and pressure  Erosion exposes rocks Thinking More about Cycles  Beach erosion  Beaches are dynamic environments  Sand is continuously removed and replaced in coastal environments

Chapter 19: Ecology, Ecosystems and the Environment 

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Great Idea o Ecosystems are interdependent communities of living things that recycle matter while energy flows through Ecology and Ecosystems  Ecology: the study of natural living systems in the broadest sense  Ecosystems: all the different kinds of living things that live in a given area, together with their physical surroundings  biotic and abiotic components = include the biota and the environment  Community: together diverse organisms form

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 producers, consumers, decomposers Characteristics of Ecosystems  Biomes: the assembly of species found together in a particular climate region  Ecosystems Consist of Living and Nonliving Parts  Abiotic (NONLIVING) o Chemical and physical environment  Water, soil, atmosphere o Different for marine and land ecosystems  Biotic (LIVING) o Living organisms o Ecological community - all interacting individuals in an area that maintain life  Forest Example: trees, insects, birds, fungi, bacteria  Energy Flows through Ecosystems  Food Web/Chain o Interaction of organisms  Trophic Levels o Primary Producers: photosynthetic organisms o Consumers: herbivores, carnivores o Decomposers  Most energy is lost as heat o Only 10% is transferred from each trophic level  As energy flows through an ecosystem it must be replaced continuously  Matter (nutrient) is recycled by ecosystems  Atoms continuously cycle – will never leave the planet o Can go through many different chemical reactions  Carbon cycle  Nitrate (a nitrogen compound)  Phosphate (a phosphorus compound)  Every Organism Occupies an Ecological Niche  Ecological Niche o Mode of survival – a particular way of obtaining matter and energy within an ecosystem  Each plant/animal fills a niche o Organisms compete for dominance in their preferred ex  Stable Ecosystems Achieve a Balance among Their Populations  Homeostasis o Balance of energy and matter (nutrients) among populations  Resources are Limited  must be shared among all individuals in an ecosystem o Some variation in populations o Overall distribution of species is relatively constant

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Ecosystems NOT Permanent – Change over Time  Long Time Scale o Plate tectonics will change climate  Short Time Scale o Glaciers, changes in precipitation pattern o Human impact Threats to the Global Ecosystem and Environment  Resources are vast but limited o The Problem of Urban Landfills  Garbage - Solid Waste  Landfills  Cut off air and water, decomposing bacteria does NOT grow  Decay or decomposition is slowed enormously  Response  Recycling  Different Kinds of Trash in Urban Landfills  Paper – 39%  Hard Waste – 19%  Plastics – 9%  Technology  The science of recycling o Saves plastics/papers from being thrown into landfills and decreases energy used to make these products o Great deal of science/engineering involved o Different processes for different materials o Paper example o Acid Rain and Urban Air Pollution  Burning introduces chemicals  Carbon dioxide and water vapor always released  Nitrogen oxides, sulfur compounds, hydrocarbons  Effects  Air pollution o Production of bad ozone (O3)  Caustic, stinging gas  Causes damage to human respiratory system o Intensity of air pollution varies on daily basis  Smog – brownish stuff seen over major cities during the summer o Product of modern air pollution  Acid Rain – a rain of dilute acid rather than water o Extra acidity is produced by human activities o Limestone monuments destroyed by acid rain  Reduction  Reduce emissions o Power plants

14 o Vehicles Acid Rain Destruction  Sandstone statue ruined after 60 years o The Ozone Problem  Ozone  Molecules of 3 oxygen atoms  Absorbs ultraviolet radiation (UV)  The ozone layer  Detection o Aircraft sampling – NOAA o Measure spectral lines from molecule  Stratosphere – contains ozone layer o Highest concentration of ozone (although all layers of atmosphere have some ozone) o Ozone layer = 30 kilometers up  The ozone hole o Area above Antarctica where the concentration of the trace gas ozone h...