Earth Science Exam 4
List two alternatives to hard stablization, indicating potential problems with each one. 10
10/ Beach Nourishment (not a permanent solution to the problem of shrinking beaches, additionally it can be very costly because huge volumes of sand have to be transported from elsewhere) and the other alternative is Relocation (the relocation of buildings and coastal properties at high risk areas of the beach and letting nature reclaim the beach.
When intrusive bodies cool and chrystallize what are 4 of the diff, types they take?
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Describe Ocean-Temp change with depth in both the high and low altitudes. Why do high latitude waters usually lack a thermocline?
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Describe density variation with depth in both the high and low latitudes. Why do high latitude waters generally lack a pycnocline?
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What is beach drift? How is it related to a longshore current? Why are beaches often called rivers of sand? 10
10/ Beach drift is the transport of sediment in a zig zag pattern along a beach caused by the uprush of water from obliquely breaking waves. Long shore currents act in similar way, and the beach is often characterized as a "river of sand" because both rivers and coastal zones move water and sediment from one area (upstream) to another (downstream)
What is the driving force of deep ocean circulation? Why is the movement of deep currents often termed Thermohaline circulation? 10
10/ Deep Ocean Circulation is caused by differences in temperature and salinity, thus giving it the reference of Thermohaline, which means heat and salt, circulation.
List the types of hard stabilization and describe what each is intended to do. What effect does each one have on the distribution of sand on the beach? 10
10/ Hard stabilization includes groins(barriers built at a right angle to the beach to trap sand that is moving parallel to the shore, often doing their jobs so well that the long shore current beyond the groin becomes sand starved and as a result the current erodes sand from the beach on the downstream side of the groin), breakwaters ( designed to protect boats from the force of large breaking waves by creating a quiet water zone near the shore, however the reduced wave activity causes sand to accumulate), and seawalls (designed to armor the coast and defend property from the force of breaking waves, however the beach to the seaward side of the seawall experiences significant erosion and may eventually be eliminated entirely.)
How do currents influence climate, give at least one example? 10
10/ There is a net gain of energy in lower latitudes and a net loss at higher latitudes. Because the tropics are not becoming progressively warmer, nor the polar regions colder, there must be a large scale transfer of heat from areas of excess to areas of deficit. The transfer of heat by winds and ocean currents equalizes these latitudinal energy imbalances.
Describe the process of coastal upwelling. Why is an abundance of marine life associated with these areas? 10
10/ Upwelling, the rising of cold water from deeper layers to replace warmer surface water, is a common wind induced vertical movement. Coastal upwelling occurs in areas where winds blow towards to equator and parallel to the coast. Upwelling brings greater concentrations of dissolved nutrients to the ocean surface, thus promoting the growth of plankton, which in turn support extensive populations of fish and other marine organisms.
What is the primary driving source of surface ocean currents? How do the distribution of continents on Earth and the Coriolis effect influence these currents? 10
10/ Wind is the primary source of surface ocean currents. The Coriolis effect influences currents. This is due to earth's rotation, currents are deflected to the right of the northern hemisphere and to the left of the southern. As a consequence, gyres flow in opposite directions in the two different hemispheres.
Diff, btw Pahoehoe and aa lava flows
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Diff. btw magma and lava?
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Highly viscous material in which situations can be very explosive, why?
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Viscosity and its role in volcanic eruptions, what effects viscosity?
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Volcanoes that form at divergent boundries are made up of basalt are shield volcanoes, those that form at convergent boundries are composite cone volcanoes.
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Describe the ocean's layered structure. Why does the 3 layer structure not exist in high latitudes?
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Describe the processes that effect salinity.
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Diff. btw active and passive cont. margins in relation to plate tectonics .
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How does the area of the earth's surface covered by the ocean compare with the area of the continents? (Describe the distribution of land and water on earth)
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List 3 subdivisions of passive continental margin. Which subdivision is considered a flooded extension of the continent and which has the steepest slope?
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Name the 4 major ocean basins, and which is the largest and which is the smallest, deepest and shallowest, which is almost entirely in the southern hemisphere, and which is almost entirely in the northern hemisphere?
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Salinity? What is the ocean's average salinity?
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What are the 2 primary sources of the materials that comprise the dissolved components in sea water?
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Why are abyssal plains more extensive on the floor of the Atlantic rather than on the Pacific?
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Discuss the origin of Ocean tides. Explain why the Sun's influence of Earth's tides is less than half that of Earth's moon, even though the sun is so much more massive than the moon. 10
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How do Diurnal, semidiurnal, and mixed tidal patterns differ? 10
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Relate the damming of rivers to the shrinking of beaches at some locations along the west coast of the US. 10
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What is a gyre? How many currents exist within each Gyre? Name the five subtropical gyres. 10
10/ A gyre are huge circular - moving current systems that dominate the surfaces of the ocean. The five subtropical gyres are the "North Pacific","South Pacific","North Atlantic","South Atlantic", and the "Indian Ocean."
2 Hazards created from volcanoes?
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3 diff. types of volcanoes?
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