Oceans 100 Exam 1 Study Guide PDF

Oceans 100 Exam 1 Study Guide CHAPTER 1 QUESTIONS: how is kinetic and heat energy applied to oceanography Science: the study of the world around us Scientific method: observation, hypothesis, testing, theory (highest level of framework) Scientific theory: structure of ideas that explain the wid...

Oceans 100 Exam 1 Study Guide CHAPTER 1 QUESTIONS: how is kinetic and heat energy applied to oceanography Science: the study of the world around us Scientific method: observation, hypothesis, testing, theory (highest level of framework) Scientific theory: structure of ideas that explain the wide range of observations, supported by abundant evidence - gets revised Ex: geology - plate tectonics Biology - evolution by natural selection Physics - gravity, motion, relativity Astronomy - big ang theory Fields in oceanography: marine biology, geography, geology, chemistry, physics, astronomy, engineering Earth\'s system: Atmosphere - space Lithosphere - outer rocky layer of earth Biosphere - all life on earth Hydrosphere - all water on earth Representations of earth: Block diagram: 3 dimensional view Map view: view from above Cross sectional view: view as if cut in half, symmetrical Mercator projection: distorts size of objects in latitude in polar regions (LAB1, greenland looked same size as australia when australia ia 4x larger) 5 big oceans: arctic, atlantic, pacific (largest, deepest (mariana trench)), indian, antarctic (shallowest, smallest (surrounded by shelves)) Ocean facts to know: 97% of all water on earth, 3% glaciers 71% of earth\'s surface, 29% land How deep are the oceans: 3.8 km, 12,000 ft Deepest ocean: mariana trench; why: sea floor age - dense, cold Age range of sea floor: 0-200 million years; why: sea floor gets recycled in trenches Ocean age: 4 billion years Average ocean temp: 4 degrees C, right above freezing; only warmed at surface by sun Most abundant elements: hydrogen, oxygen, sodium, chloride Life: 4 billion years old 2.5 billion years ago: photosynthetic algae ---\> O2 to atmosphere Last 600 million years: rich diversity - animals Evolution of atmosphere: 79% nitrogen, 21% oxygen Energy: capacity to do work Kinetic energy: solar radiation Heat energy: gravitational potential and chemical energy Convection: a means of heat energy transfer Convection: sinking of cold air because it\'s denser - physical movement Liquid, gas, viscous rises HOT, LESS DENSE, RISES COLD, MORE DENSE, SINKS Temp + density in the oceans: thermal expansion - leads to warm water when... The density is lower, the energy is higher, in tropical places Plate tectonics: when convection in mantle moves plates Oceans crust (basalt) is more dense than continental crust Supernova: great explosion of a star Earth condensed out of a solar nebula Solar nebula: cloud of gas and dust Density = mass / volume Density differentiation = layers Denser metals (iron, nickel): go to core Lighter silicate rocks: go to surface Lithosphere: crust + uppermost mantle -100 km thick -Rigid plates Asthenosphere: upper mantle below -600 km thick -ductile rocks Mesosphere: lower mantle Formation of asthenosphere + oceans: volcanic outgassing Oceans: H2O condensed and rained down, icy comets Hot spots: deep mantle plumes of hot rocks rise by convection Plates move over hot spot \*\*\*EXAMPLE: Hawaii, volcanic islands get older in the direction of plate motion Plate - pacific, motion - NW Youngest volcano: Loihi - future volcano, SE to big island Job of oceanic plate: subduct then come up years later \*\*\*If plate is moving NW, youngest island is SE \*\*\*Geographical example of oceanic-continental convergence with subduction: cascades Lithosphere is broken into plates, move over asthenosphere... lots of evidence 1. a. b. c. d. Breakup / rifting of a continent: asthenosphere breaks through lithosphere into crust 2. e. f. 3. g. h. i. 4. j. k. l. 5. m. n. o. p. \*\*\*Mid-ocean ridges: Record magnetic field of the earth Polarity reversals: symmetric about the mid-ocean ridge If rocks are same on each side of ridge, solarity is the same 6. q. r. s. t. \*\*\*Lithospheric plates: SAN DIEGO IS PACIFIC PLATE Moving to NW because of convergent boundaries Forces for plate motion - gravity = slab pull Slab pull: subduction zone (stronger) Mantle convection: very hot rocks at surface, very cold rocks sink to bottom 7. u. 8. v. Different types of plate boundaries: 1. a. b. 2. - - - - - - 3. c. d. Marine provinces: based on bathymetry Bathymetry: measurement of depth in the ocean 1. 2. 3. Hypsometric curve: shows mountains compared to sea level 70% of earth\'s surface is below sea level Oceanic - denser Continental - thicker F-gravity + F-boyancy cancels out (opposite of gravity) Isostasy: crust floats in equilibrium on mantle 1. a. b. c. d. e. f. g. \*\*\*Why does oceanic lithosphere at ridges rise higher than trenches? Its less dense, hotter, over magma Passive margin (atlantic type margins): -Passively rifting away -Within a plate -Little tectonic activity -Larger/wider shelf Active margin (pacific type margins): EXAMPLE: cascades, mount saint hellen -At plate boundary -Convergent -Transform -Narrow shelf -Active tectonics \*\*\*San Francisco margin? Active - transform boundary, SAN ANDREAS FAULT Arctic ocean: shallowest sea because lots of shelves Seafloor sediment: goes gravel, sand, salt (courser) ---\> clay (finer) 4 sources: 1. 2. 3. 4. Sediment made up of fossils: chalk \*\*\*What ocean has thickest layers of sediment? Atlantic \*\*\*Why? It\'s much smaller, more sediment accumulates, passive margins, lare shelves Pacific ocean: less sediment, greater area, trenches Atlantic ocean: more sediment, smaller area, passive margins, rivers \*\*\*Is there sediment over mid-ocean ridges? No, volcanic 2\. Deep ocean basins: abyssal plains, volcanic peaks, trenches a. b. c. Round/uneven surface: never above sea level / never an island Deep sea trenches: found at convergent boundaries (subduction zones) Mariana trench: deepest trench Old, deep, cold, dense Jacques piccard, don walsh - 1960 - 35,800 ft below sea level (farthest down mariana trench) James cameron - 2012 - 34,000 ft below sea level (first solo dive) 3\. Mid-ocean ridges: a. b. c. \*\*\*How can there be life in absence of sunlight? Magma chambers Source of energy: magma chambers