Earth Sciences 1086F/G Chapter Notes - Chapter 7: Thuban, Expulsion Of The Acadians, Continental Drift
5 Aug 2020
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[Type here] Chapter 7 Week 3
1. Why does the Earth’s North Star change? What is ours now and the order of them?
-Because of how the Earth rotates, the position of the poles change, and thus so does
the North Star. Back awhile ago it was Thuban, now it is Polaris, and in 12,000 years it
will be Vega.
1A) What is the gas percent of Earths Atmosphere?
-78% Nitrogen and 21% Oxygen, and 1% other metals
1B) What is responsible for the seasons?
-The Angle of obliquity or the tilt angle of 23degrees that the Earth’s rotational axis is
tilted.
2. Be familiar with
a. Size, density and internal zones
b. Continental drift, plate tectonics, and magnetism
c. Geological time and age dating
d. Basic properties of the hydrosphere and atmosphere
e. How early life developed
i. Whenever the momentous life-event occurred, the biosphere slowly
started to change the atmosphere in ways that made it friendlier for the
biosphere to grow ever larger. Indeed, the atmosphere eventually
became so friendly that, by several hundred million years ago, it was
possible for life to leave the sea, stay continuously in contact with the
atmosphere, and spread to the land.
3. What makes Earth unique among the terrestrial planets?
a. It is the densest major body in the solar system, it was one permanent natural
satellite. It has a very strong magnetic field.
4. Explain the role of Accretion in the formation of the Earth
a. The accretion method is how the Earth came to be which is the growth by
accumulation of smaller bodies, dust and gas, and smaller objects. The large
object would attract others by gravity and eventually it would grow, attract more
material, and grow into a protoplanet and then a planet.
5. What is the iron catastrophe? How was the core formed? What are the layers of the
core?
[Type here] Chapter 7 Week 3
a. The Iron catastrophe explains how Earth’s core is formed. In the formation of
Earth during the Accretion method, lots of bodies would be hitting the future
Earth, which each body having its own Kinetic Energy. The two kinetic bodies
hitting each other resulted in kinetic energy being transformed into heat energy.
This ended up producing so much eat that hot iron from the upper layer of
Earth’s surface began to sink under its own great weight (since iron is the
heaviest element out of the ones that make up Earth). The great upheaval of the
planet produced by iron sinking to the planet’s core released more energy and
caused the whole planet to melt. This resulted in a whole lot of Earth’s iron being
removed from the upper layers to the middle of the Earth and formed a liquid
core. As Earth continued to grow, the pressure of the innermost core became so
great that it turned from a liquid to a solid. So now we have a solid inner inner
core made of metal surrounded by a liquid metal outer core. The elements that
make up Earth are Iron (Fe), Oxygen (O), Magnesium (Mg), Silicon and these
other elements since they are lighter ended up at the Earth’s surface.
6. What is the most common element in the Earth?
a. Iron (30%)
7. How did differentiation form different zones in the Earth?
a. Differentiation is the zonation of elements from heaviest at the core to lightest
at the top. (This isn’t completely homogenous because there are some lighter
elements at the Earth’s surface).
8. Name the zones of the Earth (be able to label a simple diagram). How do the zones
differ from each other? Which is the largest zone?
[Type here] Chapter 7 Week 3
a.
-There are two different ways to kinda label Earth. One is (Core, Mantle Crust). Now, it is Inner
Core, Outer Core, Mesosphere, Asthenosphere, and Lithosphere.
Document Summary
Because of how the earth rotates, the position of the poles change, and thus so does the north star. Back awhile ago it was thuban, now it is polaris, and in 12,000 years it will be vega. 78% nitrogen and 21% oxygen, and 1% other metals. Week 3: the iron catastrophe explains how earth"s core is formed. Earth during the accretion method, lots of bodies would be hitting the future. Earth, which each body having its own kinetic energy. The two kinetic bodies hitting each other resulted in kinetic energy being transformed into heat energy. This ended up producing so much eat that hot iron from the upper layer of. Earth"s surface began to sink under its own great weight (since iron is the heaviest element out of the ones that make up earth). The great upheaval of the planet produced by iron sinking to the planet"s core released more energy and caused the whole planet to melt.
