Transcript this process

1. What is the difference between geosphere and the
lithosphere?
ANS: The geosphere is the solid portion of the Earth, and includes the
lithosphere (which only includes the planet’s crust, and upper mantle.)
2. Which of Earth’s systems would gaseous H2O belong in
(list all please)
ANS: The atmosphere; the hydrosphere
3. The most prevalent gas in today’s atmosphere is…
ANS: Nitrogen (diatomic molecule N2)
4. What gas wasn’t present in Earth’s early atmosphere that
is now present, making aerobic life possible?
ANS: Oxygen
5. Describe one reason why the gases in Earth’s first
atmosphere (hydrogen and helium), were lost to space.
ANS: Earth wasn’t differentiated yet, and therefore had no
magnetosphere, so the sun’s solar wind could have “blown” it away. Also,
these elements are very light and may have just dissipated into space.
6. What is probably the origin of Earth’s second
atmosphere? (Containing CO2, SO2, CO, S2, Cl2, N2, H2) and NH3
(ammonia) and CH4 (methane)
ANS: Volcanic outgassing
7. Describe one way that Earth’s Oceans could have
formed.
ANS: Comets delivered the water; Outgassing of H2O from volcanic
activity; followed by torrential rain from condensation in the
atmosphere
8. How much of today’s atmosphere is oxygen?
ANS: 21%
9. What is photochemical dissociation?
ANS: Occurs when UV radiation breaks up water, creating O2 and hydrogen.
10.What evidence is there in the rock record that oxygen
was present at any point in the atmosphere?
ANS: Iron oxide (rust) present, means water and oxygen was present. BIFs
and red beds, which are rocks that are completely red
11. Why is there so much N2 in our atmosphere today?
ANS: Because it is relatively chemically inactive, and just sticks around as
a result
12. What outgassed molecule chemically reacted with the
O2 produced through photochemical dissociation, helped
to created even more nitrogen in our atmosphere?
ANS: Ammonia (NH3)
13. Where is Earth’s biosphere?
ANS: It is above, on, and under the surface of the Earth…wherever there
is life.
14. Why is the formation of ozone (O3) so important to
Earth’s biosphere?
ANS: Ozone in the stratosphere protects living things from dangerous UV
radiation.
15. What are anaerobes?
ANS: Organisms that usually die in the presence of oxygen
16. Why do scientists think these anaerobes were the first
forms of life on Earth?
ANS: because there was no free oxygen in Earth’s early atmosphere,
aerobes (organisms that need oxygen) could not have lived there.
17. What gases did these early anaerobic “methanogens”
require to survive (Why was early Earth a “paradise” for
them?
ANS: CO2 and Hydrogen
18. Cyanobacteria were one of the first life forms to use
this process to add oxygen to the atmosphere.
ANS: Photosynthesis
17. Cyanobacteria are also important because of their
contributions to the cycling of nitrogen. Why is nitrogen
important to the biosphere?
ANS: Nitrogen is an important ingredient in the biomolecule protein…which
is made of amino acids bearing nitrogen. Nitrogen is important because
proteins build animal and plant bodies
18. From the initial GOE, and for the next two billion years
after it, what happened on Earth?
ANS: We have no idea!
19. Where is the Earth’s crust thicker, under the
continents, or the ocean?
ANS: Under the continents.
20. What is the name of the “plastic” part of the mantle
that contains the convection currents that drive the
Earth’s tectonic plates?
ANS: Asthenosphere
21. What form of energy transfer occurs when we snuggle?
ANS: Conduction
22. How is energy transferred through the vacuum of
space?
ANS: Radiation
24. Which of our Oceans is getting larger because of a midocean ridge?
ANS: Atlantic
25. When Earth’s atmosphere began Analysis
changing,
andVolcano
the GOE
of Gases from Hawaiian
occurred, what happened to the anaerobes?
Gas
Amount
ANS: They either became extinct, or they
moved to extreme79%
environments
H O (steam)
12%
on Earth where little if any oxygen exists.
CO
2
2
SO2
N2
H2, CO, Cl2, and Ar
6.5%
1.5%
trace
26. Using the table to the above, you can see what types of
gases are prevalent in today’s volcanic outgassing. What
geological principal tells us it was the same on early Earth?
ANS: Uniformitarianism
27. Which of these gases would have been most helpful to
cyanobacteria?
ANS: CO2