EOSC 114 Final Exam Prep. Questions And Well Elaborated Answers Graded A+

iron, nickel, oxygen - correct answers 1st, 2nd, and 3rd most common elements in the earth core oxygen, silicon, aluminum - correct answers 1st, 2nd, and 3rd most common elements in the earth crust oxygen, hydrogen, chlorine - correct answers 1st, 2nd, and 3rd most common elements in the ocean nitrogen, oxygen, argon - correct answers 1st, 2nd, and 3rd most common elements in the atmosphere less-dense materials float on top of denser materials - correct answers how does density relate to stratification? a substance that has no fixed shape and yields easily to external pressure; a gas or a liquid - correct answers define fluid how thick a fluid is; measure of resistance to flow; depends on temperature and chemical structure; high viscosity means that the matter is thick and has a slow flow; low viscosity means that the matter is runny and has a quick flow - correct answers define viscosity able to be squeezed or expanded so that the mass fills less or more space; results in a change of density (mass/volume) of the object, because of the volume change - correct answers compressibility probability that any given hazardous event might occur (chance of potential loss) - correct answers define risk the work needed to raise an object of mass (m) a distance (z) against the pull of gravity (g) - correct answers define potential energy (PE) a moving object possesses kinetic energy - correct answers define kinetic energy (KE( heat energy we can sense or feel (or measure); when we measure temperature we are measuring this; on an atomic level this is really particle motion - correct answers define sensible heat "hidden" heat energy in chemical bonds between atoms; sensible heat "stored" as latent heat during melting or boiling (or sublimating); latent heat released as sensible heat when condensing or freezing (or depositing); when liquid becomes gaseous heat is taken from surroundings; when has becomes liquid heat is transferred/released to the surroundings - correct answers define latent heat disasters - correct answers what are the result of an excess of energy? composition, heat, and gravity - correct answers what are plate tectonics controlled by? low density rock that rises above; continental crustal rock is very different than the rock that comprises the oceanic crust - correct answers define crust thick, rocky layer, very similar to oceanic crustal rock - correct answers define mantle solid outer layer of the earth; cool, solid exterior shell, quite brittle, a little ductile - correct answers define lithosphere almost melting, still solid (less than 5% melted), very ductile, NOT brittle - correct answers define asthenosphere heating at the rift raises the ridge crest, gravity pulls the elevated plates down and apart - correct answers define ridge push the weakest, least time deforming before brittle failure, smallest maximum earthquake size, very shallow depth range, lots of little quakes, occur in mid-ocean ridges - correct answers describe divergent plate boundaries the strongest, cool rock and in compression, more time deforming before brittle failure, largest maximum earthquake sizr - correct answers describe convergent plate boundaries transform boundaries are in the middle, generally warm-to-cool rock in shear, moderate force applied before brittle failure, (strike-slip fault motion) - correct answers describe transform plate boundaries a geological fault in which the hanging wall has moved downward relative to the footwall, occur where two blocks of rock are pulled apart, as by tension - correct answers describe a normal fault the hanging wall has moved upward relative to the footwall, occur where two blocks or rock are forced together by compression - correct answers describe a reverse fault a fault in which rock strata are displaced mainly in a horizontal direction, parallel to the line of the fault - correct answers describe a strike-slip fault in the lithosphere - correct answers where do all earthquakes occur? as rocks on opposite sides of a fault are subjected to force and shift, they accumulate energy and slowly deform until their internal strength is exceeded - correct answers explain elastic rebound through solid or fluid, fastest, often the smallest amplitudes, near-vertical ground motion is the least destructive, duration is the strongest - correct answers describe P-waves only through a solid, can't 'bend' a liquid or a gas, large amplitudes, near horizontal ground motion is very destructive - correct answers describe S-waves speed depends on ground conditions, slowest waves, often the largest amplitudes, rolling motion most destructive, longest duration - correct answers describe surface waves (rayleigh and love) ground shaking, building design, soil properties, fire, tsunami, landslide - correct answers earthquake hazards (6) (i) megathrust locked zone - brittle enough for the rupture to start, possible hypocentre location (ii) transition zone - too ductile for hypocentre, but fault could rupture this deep once it has started (iii) trench - location of plate boundary on the surface and the tsunami starting location - correct answers what are the 3 regions of earthquakes in a subduction zone? (Cascadia is a subduction zone) low viscosity, low silica, hot temperature - correct answers describe characteristics of mafic magma (viscosity, silica content, and temperature) high viscosity, high silica, cool temperature - correct answers describe characteristics of felsic magma (viscosity, silica content, and temperature) explosivity - correct answers viscosity and gas content are related to what? low gas content and fluid, quiet, effusive eruptions, gas escapes - correct answers mafic explosions high gas content and gooey, explosive, gas kept under increasing pressure - correct answers felsic explosions basalt, low volatile content, low viscosity, VEI (0-1), fissure eruptions, low-volatile lava flows create wide volcanic plateaus of nearly horizontal volcanic rock levels - correct answers icelandic eruption type basalt, low volatile content, low viscosity, VEI (0-1), after initial venting of gas, great quantities of basaltic lava spill out of fissures and flow down mountain slopes - correct answers hawaiian eruption type basalt & andesite, medium volatile content, low and medium viscosity, VEI (1-2), not strong enough to break cones, gas pressure builds quickly beneath the crust, and eruptions occur as distinct and separate bursts - correct answers strombolian eruption type basalt & andesite & rhyolite, medium-high volatile content, medium-high viscosity, VEI (2-4). Eruptions alternate between thick, highly viscous lava and masses of pyroclastic material - correct answers vulcanian eruption type andesite & rhyolite, high volatile content, high viscosity, VEI (3-8), incredible gas-powered vertical eruption columns, final phase in a major eruptive sequence - correct answers plinian eruption type dark colour, 45-55% SiO2 content, low viscosity magma, peaceful eruption - correct answers volcanic rocks - basalt medium colour, 55-65% SiO2 content - correct answers volcanic rocks - andesite light colour, 65-75% SiO2 content, high viscosity magma, explosive eruption - correct answers volcanic rocks - rhyolite high silica content, cooler magma temps, and higher viscosity - correct answers what do explosive eruptions require? a lava flow with a rough, blocky surface; slower-flowing, more viscous - correct answers define aa lava a lava flow with a smooth, ropy surface; highly liqui