Article Questions - The Evolution of Our Atmosphere 2015
Ref: “As the World Breathes: The CO2 Cycle”, Earth Magazine, Jan., 1992
[from Front Page and Diagram Page and from PowerPoint discussion with teacher]
T or F 1. The atmospheres of Venus and Mars are almost entirely composed of oxygen.
2. Earth’s early atmosphere was most likely almost pure CO2. Where did it go? (choices.)
____into limestone hills and mountains____ most of it drifted into outer space
____to the bottom of the seas____it broke down into carbon and oxygen
T or F 3. Most of Earth’s original atmosphere is locked up in itsrocks.
T or F 4. We are virtually standing on our ancient atmosphere.
5.Rain containing carbon dioxide is slightly acidic, so rock is ______by this rain.
6. As carbonated groundwater drips into a cavern, it evaporates. As the dripping water
evaporates, the minerals (calcite) ______to form stalactites and stalagmites.
7.Marine organisms (in the ocean) tie up calcium and carbon dioxide to make ______(including coral reefs!!).
8.When these sea organisms die, their calcium carbonate remains collect in layers on the
______floor and eventually turn into ______.
9.Carbon is eventually re-released from the crust back into the atmosphere by ______.
10.Forests“inhale” _____ and produce ______as a byproduct during photosynthesis.
[Article, p. 28, col.1 & 2]Matching – Goldilocks & the 3 Planets
____11.Too hot-never learned to “inhale” CO2into its rocks A. Earth
____12.Too cold – never learned to “breathe” CO2back out of its crust B. Mars
____13.Just Right – achieved a balance, taking injust as much C. Venus
CO2 as it releases
14.a)From Earth’s beginnings 4.5 billion years ago until 3 b.y. ago, the sun was only
_____ % as bright as it is today. (icebergs in Panama!!)
b)This dim sunlight might have allowed the earth to remain a solid ball of rock and
______, but geologists tell us that the oceans have always been ______.
c)The ______effect is responsible for keeping our oceans liquid.
____15. When sunlight warms our skin, it glows with a) infrared or b) ultraviolet radiation.
T or F 16.We’d be better off if all of the CO2 were stripped from our atmosphere.
T or F 17.No, we wouldn’t! - a littlegreenhouse effect is a good thing.
T or F 18.If noradiantenergy escaped our atmosphere, Earth would be much nicer.
(p. 29) 19.Liquid oceans are critical to life because they give us ______(the wet kind).
20. The early atmosphere was very low in oxygen (O2). As a result, there was no ______(O3) layer to hold back the dangerous scorching rays of purplish ______light.
21.Life’s“strategy for survival” in the presence of this deadlyU.V.radiation was to
______.
22. Earth was changed forever by the arrival of the greenpigment ______.
23. This pigment is essential to photosynthesis, which led to a huge increase in the amount
of ______(O2) in the atmosphere over the next 2 billion years.
24. The early oceans had lots of dissolvediron. Higher levels of ______(O2) oxidized (rusted) the iron in the sea water during the Pre-Cambrian Era, These iron oxides settled out to make massive beds that are mined today as ______ore deposits. (p.29 - 32)
(p.32) 25.Increasing levels of O2 not only ravaged the oceans, they helped to allow life on land
by creating an ______(O3) layer which blockedout much of the U-V light radiation.
26. Our atmosphere became oxygen-rich a brief ______million years ago. (1/9thEarth’s age)
Part II - The Geochemical Cycle (p.32, col.2)
27. A single geochemical cycle removes one molecule of ______from the atmosphere and
locks it in ______:[ CaO + CO2 CaCO3 ]
28. To do this, water containing CO2 dissolves Calcium silicates. The carbon from this
dissolved rock is locked up in a new variety of rock: ______.
T or F 29. Early atmosphere had so much CO2- atmospheric pressure was 60 times
greater than it is today.
T or F 30. If today’s atmosphere is 1 unit, there are 100,000units locked up in rocks.
T or F 31. There is roughly half as much carbon in the rocks of Earth as there is in the atmosphere of Venus.
T or F 32. The earth’s geochemical engine takesover3 billion years to turn over.
(p.33)T or F 33. All the carbon locked up in oceanfloors has a chance to getfree again.
34.CO2 is released from the rocks through ______eruptions.
35.Metamorphic heat and pressure cause chemical reactions which release CO2. The CO2
rises and dissolveseasily with ground______, making it naturally carbonated.
36.What historicevent caused CO2 levels to start rising sharply 200 years ago?
______
____37.The “pages in the lab book” that allow us to study Earth’s ancient atmosphere are:
a)pp. 317-322 of Grolier’s GuidetoEarth-Building.
b)pp. 478396-482417 of TheHitchhiker’sGuidetotheGalaxy.
c)the layers of sedimentary rock that lie below us.
d)pp. 1 - 10 in ZenandtheArtofGeologicalMaintenance
T or F 38. We have confirmed that, when the temperaturewentup, atmospheric CO2
levels were higher as well.
T or F 39. When global temperaturesfell, however, the CO2levelsstayed high.
40.High CO2 levels during the Cretaceous Period (the age of dinosaurs), caused warmer
temperatureswhich allowed life to ______(and left behind lots of coal & oil!).