Term
| One of the feedback mechanisms amplifying the periodic variation in sunlight reaching the earth (over the past 0.5 m.y.) calls upon increased winds and dust during glacial times. How does this affect global temperatures and climate? |
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Definition
| Increased winds blow dust into the oceans, which releases iron into surface waters, stimulating marine photosynthesis (because iron is a limiting micronutrient) and lowering atmospheric CO2 and temperature |
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Term
| If all of the ice in the Antarctic melted today, how much would sea level rise? |
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Definition
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Term
| What is true about ultra-violet light? |
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Definition
| Ultra-violet light has a shorter wavelength and more energy than visible light |
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Term
| What approach has been used to replace freon and other CFC gases in an effort to reduce ozone destruction? |
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Definition
| Make gases that are more reactive so that they are destroyed/removed in the lower atmosphere |
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Term
| In March why do you get sun burned at the equator faster than in Raleigh? |
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Definition
| The angle of the sun is directly overhead at the equator, which minimizes the thickness of the atmosphere through which the UV light must penetrate |
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Term
| The triggering force behind the glacial/interglacial transitions for the past 700 thousand years is _____________, whereas the mechanisms that amplify this trigger into global climate changes are feedback mechanisms such as ______________ and _________________. |
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Definition
| Changes in solar radiation reaching the northern hemisphere as predicted by Milankovich; marine iron fertilization during glacial times and coral growth on continental shelves during glacial/interglacial transitions |
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Term
| Two of the most important human-made chemicals that threaten the ozone layer are: |
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Definition
| Freons (supplying Cl or chlorine) and halons (supplying Br or bromine) |
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Term
| 9. In the chapter on Long Term Climate Change we talked about the “Snowball Earth” during which time much of the planet was frozen. About how long ago did it occur and what is the primary evidence for thinking that most of the earth was covered with glacial ice? |
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Definition
| 800 to 600 million years ago; Australia was at the equator and the geological evidence shows that most of this continent was covered with ice at this time |
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Term
| What was the effect on climate when the continent of India tectonically “crashed” into Asia and why? (NEED TO FULLY UNDERSTAND) |
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Definition
| Cooler climate because it formed the Himalayan Mountains that weathered, lowering the atmospheric carbon dioxide levels |
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Term
| What causes most surface ocean circulation such as the Gulf Stream off of our North Carolina coast? |
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Definition
| Winds blow across the surface of the ocean and friction between the air and ocean causes the circulation |
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Term
| Which of the following is the result of an oceanic plate subducting underneath another oceanic plate? |
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Definition
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Term
| Although most geological evidence opposes this conclusion, what might have caused the earth to be a frozen planet (mean temperature below the water freezing point) for the first billion years of its existence? |
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Definition
| A cooler sun providing less radiation to the earth |
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Term
| What was not used as evidence in developing the theory of plate tectonics (i.e., continental drift)? A. The complementary shapes of the continents (e.g., Africa and So. America) |
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Definition
| The mean elevation of the continents has remained essentially constant over geologic time |
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Term
| The Coriolis effect in the northern hemisphere is to the _________; consequently the atmospheric circulation around a northern hemisphere high pressure area is _____________? |
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Definition
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Term
| At the equator more solar radiation is ____________ than ______________. The opposite is true at the poles. The surpluses and deficiencies in heat are balanced as a result of _______________. |
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Definition
| Absorbed; Emitted; winds and ocean currents |
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Term
| What processes probably kept the earth from being a frozen planet during the first billion years of its existence? |
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Definition
| High concentrations of both carbon dioxide and methane in the atmosphere (increased greenhouse concentrations relative to today) |
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Term
| During the Mesozoic era (245 – 65 million years ago) dinosaurs ruled the earth. What were global conditions like? |
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Definition
No ice caps anywhere on earth
Atmospheric carbon dioxide levels were 4 times greater than today
Sea floor spreading rates were faster releasing carbon dioxide to the water column and ultimately to the atmosphere
Deep ocean temperatures were much warmer (15 degrees C instead of 0 to 4 degrees C like today) |
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Term
| How do deep earthquakes tie into Plate Tectonic theory? |
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Definition
| Deep earthquakes commonly occur where oceanic crust is subducting down under continental crust or another oceanic plate |
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Term
| The plate movements at a mid-oceanic ridge are _______________ and represent a plate _______________. |
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Definition
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Term
| At the center of an oceanic gyre, the relative sea level is ____________ and in general it is an area of ____________ primary production (i.e., marine algal growth). |
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Definition
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Term
| Why isn’t there an Arctic ozone hole? |
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Definition
| The air is not as cold as in the Antarctic and the air mass that sits over the Arctic during the winter breaks up before spring’s first light, so there is no increased supply of chlorine compounds for the spring light to release |
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Term
| Why don’t winds on the earth move directly from areas of high pressure to low pressure? |
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Definition
| Deflected by the Coriolis Effect |
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Term
| How do we know the boundaries and phase changes associated with the core, mantle, and crust? |
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Definition
| The penetration and reflection of seismic waves created by earthquakes and nuclear bombs through the earth |
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Term
| Air descends at the poles (i.e., 90 degrees N and S). Where else does the air descend on earth and what type of climate is typical as a result of this process? |
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Definition
| At the tropics (~ 23 to 30 N and S); desert |
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Term
| With regard to plate tectonics, what is happening at a hotspot? |
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Definition
plume of magma from the upper mantle comes to the earth’s surface, and oceanic or continental plates
move over the stationary plume |
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