Download 1 - JustAnswer

1.Why is viewing the Earth as a system a good way to study Earth? Are humans a part of
Earth system? If so, what role, if any do we play in Earth's evolution?
It is obvious that all the elements of nature work together. So seeing the entire earth as a
system is a good way to evaluate what is happening to it overall. The problem is that we
do not understand completely all the systems of the earth and so we could be misreading
entirely certain elements of the systems. Water vapor, for instance, is a “greenhouse gas”
just like Carbon Dioxide is, yet do the two have similar effects or opposite effects on the
environment? We do not know and so we make assumptions that may or may not allow
us to truly evaluate the system.
All living and non-living portions of the earth would be included in the system. Which
would mean that humans are part of the system. However, how much do humans truly
affect the system and whether or not their influences will change the system are not yet
proven. Our effect on the changes of the earth could be massive, or they could be
miniscule, and we are, of course, looking at it as if we were trying to evaluate it all in a
human time span, which may mean nothing to the planetary system.
4. Why do most scientist think that overpopulation is greatest environmental problem
facing the world today? Do you agree? If not, what do you think is the greatest threat to
our existence as species?
Overpopulation would have an effect if it were to diminish food or water supplies so that
there would be massive periods of food shortages and similar incidents. Those scientists
who see nothing but exponential rates of human population growth are most concerned.
They see nature as a continual balancing act between population, supplies, quality of life,
and lifespan and when there are huge groups consuming most of the supplies. In most
situations, when nature has any control at all, the population will drop when food supplies
become short. So far, humans have been ahead of that curve by being able to produce
more food on less land, but if the population actually does become a burden to the earth,
from observation of the rest of nature, you would have to assume that the planet would
find a way to reduce that population.
I do not believe that overpopulation is as big a problem as some people think it is,
however it is something to consider among all the other items in that system called Earth
that may be having an affect on things.
Our greatest threat to continued existence is, of course, our selves. We have greater
ability to do something very foolish and destroy each other than we have of the earth and
nature finding a way to have to do it for us. Another World War, a few nuclear bombs, or
something of that sort would change everything right away.
8. Why is plate tectonic theory so important to geology? How does it fit into systems
approach to the study of Earth?
Plate tectonics is the world theory for geology, just as evolution is the world theory for
the development of species. It shows the earth not as static, but as a continual system,
changing constantly, and causing the volcanoes, earthquakes, and more
9. Using plate movement as the driving mechanism of the rock cycle, explain how the
three rock groups are related and how each group can be converted into a different rock
group?
I do not know this one,
1. What evidence convinced Wegener and others that continents must have moved in the
past and at one time formed a supercontinent?
First they had the shape of the continents, the way South America seemed to fit into the
shape of Africa, for example. After that, they had the similarity of fossils found at certain
ages on two different continents. They had no theory about why this would occur, or
what would cause the movement, but they could see things that seemed to show a
theoretical possibility, later proven by the sea floor spreading that has been discovered, as
well as places like the rift valley in Africa, where the two plates are slowly separating and
opening the lower levels of rock to the surface and exposing fossils in great quantities.
3. How did the theory of seafloor spreading, proposed by Harry Hess in 1962, overcome
the objections of those opposed to continental drift?
It showed there actually was a “motor” something that was driving the plates apart,
slowly, continually. It shows that there actually is something that pushes the plates apart,
just that it is hidden from us under water where it cannot be seen easily.
8. Why is some type of thermal convection system thought to be the major force driving
plate movement? How have slab-pull" and "ridge-push" both mainly gravity drives,
modified a purely thermal convection model for plate movement?
Heat from the magma and the constantly melting layers of rock make it easy to see why
thermal convection was thought to be the main cause of plate tectonics. The plates could
“float” on the fluid melted rock. In a way, slab-pull and ridge-push continue this concept,
in that, for example, slab-pull means that as a plate cools and becomes dense it sinks
down under the other layer of crust, which then pulls on the slab behind it, forcing the
plate to continue to move in a certain direction. Ridge-push is even more obvious, as
hotter, molten material presses up from below and through a fault to help spread the
plates.
10. In addition to volcanic eruptions and earthquakes associated with convergent and
divergent plate boundaries, why are these boundaries also associated with the formation
and accumulation of various metallic ore deposits?
I cannot answer this one but assume it has to do with mineral deposits brought to the
surface by the magma (or taken back under by the earthquake) and becoming exposed
after there is enough erosion….