Post a New Question

sci

posted by .

Respond to the following scenario:
o Your younger brother is in 5th grade. He comes home and tells you to look at an
animation his teacher showed him in geology class.
o Review the Continents of the Past animation on this week’s aXcess page.
o After viewing the animation, your brother has a look of disbelief on his face, “C’mon,
really? Our whole continent moves? That’s bogus!” Instead of blowing him off like you
usually do, you decide to sit down and educate him about plate tectonics. First, you
give him an overview about two historical figures that contributed to the plate tectonic
theory. Then, you decide to show him how the plates move by boiling a pot of water
(shown on p. 108) and relating it to mantle convection and plate movement.
· Write a 200- to 300-word summary about the two historical figures and the process of
mantle convection and plate movement



Cold
water
sinks
Convection Cell
Cold
water
sinks
Hot
water
rises
Water cools
108 CHAPTER 4 Plate Tectonics
THE SEARCH FOR A MECHANISM
Although virtually all geologists accept the basic theory
of plate tectonics, some questions remain. What, exactly,
drives plate motion? How does the mantle interact with
the crust? What initiates subduction? Scientists have a
basic understanding of these processes, but the details
have not been completely worked out. Thermal motion
in the mantle is at least partially responsible for the motion
of plates. This thermal motion, in turn, results
from the release of heat from Earth’s interior. Let’s take
a closer look at some of the complexities of Earth’s
heat-releasing processes.
Earth’s internal heat Earth gives off heat for two
main reasons. First, it is slowly cooling off from its initial
formation processes, including formation of a molten
iron core. Second, heat is constantly being generated by
the decay of radioactive elements in the interior, primarily
uranium, potassium, and thorium. If Earth did not release
heat into outer space, the entire interior would
eventually melt.
Some of Earth’s heat is released through conduction.
This is a gentle and slow process similar to what you
feel when you hold a cup of hot coffee in your hands.
The heat moves through the wall of the cup by conduction,
a gradual transfer of energy from atom to atom.
When you boil water in a pot on a stove, you will
see the water churning around in big circles called convection
cells (see Figure 4.14A). A mass of hot water
at the bottom is slightly less dense than the cooler water
at the top, and hence it will rise. When it reaches the surface,
it sheds its heat, moves sideways as it cools, and then
sinks back down to the bottom, where it is reheated. This
mechanism of heat transfer, is more efficient than conduction.
The convection cells act like couriers, carrying
Rock
cools
Continent
Ocean
Continent
Rock
cools
Cold rock
sinks
Convection
Cell
Cold rock
sinks
Heat source
within the Earth
Ocean floor Ocean floor
Convection inside Earth drives the lithospheric plates on the surface.
A An everyday example of convection can be seen when you boil a pot of water. The water
closest to the burners is hotter than the rest of the water. As it heats up it becomes less dense
and rises to the top. At the surface it cools down and moves sideways to make room for the
hot water rising beneath it. As the water at the surface cools, it becomes denser and sinks.
B The same process happens in
Earth’s mantle on a much grander
scale and over a much longer time.
Hot rock rises slowly and plastically
from deep inside Earth, then cools,
flows sideways, and sinks. The relation
between convection cells and
lithospheric plates is far more complex
than what we see, for example,
in a pot of boiling water.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Question

    Okay, so I'm doing this project on careers and I need to find out the employment possiblities/opportunities for the career "computer animation" I couldn't find anything for animation, but the closest I got to was : - Computer Programmers …
  2. Powerpoint

    okay, I need to do a powerpoint for this career "computer animation" I need help writing a simple, short, punchy paragraph or list. Yet able to get the message across to the audience. Heres original: The career outlook for computer …
  3. geology(science) am i right?

    Respond to the following scenario: o Your younger brother is in 5th grade. He comes home and tells you to look at an animation his teacher showed him in geology class. o Review the Continents of the Past animation on this week¡¦s …
  4. geology(science) am i correct

    Respond to the following scenario: o Your younger brother is in 5th grade. He comes home and tells you to look at an animation his teacher showed him in geology class. o Review the Continents of the Past animation on this week¡¦s …
  5. geology (science)

    Review the following animations on this weeks aXcess page: o Types of Dunes animation o Glacial Landforms animation „h Compare and contrast the geological features of a desert landscape and glacial landscape. Describe at least one …
  6. History/Computer Animation

    I have to give a five minute presentation on American History using one theme and I want to use a computer animation software to help me do this, so can anyone recommend one?
  7. Geology

    Respond to the following scenario: o Your younger brother is in 5th grade. He comes home and tells you to look at an animation his teacher showed him in geology class. o Review the Continents of the Past animation on this week¡¦s …
  8. 5th grade math

    i have to write an algebraic expression for the following: jasmine has three times as many chores as her younger brother does.
  9. biology

    any site i go onto that be animation site to find out about nucleic acids and protein synthesis?
  10. Int.Science/laws of thermodynamics

    Watch the heat engine animation in the lesson text above. Does this animation illustrate a "new and improved" heat engine?

More Similar Questions

Post a New Question