Study Guide for Earth Science Midterm
1.
2.
3.
4.
5.
Name: _____KEY___________
What is difference between the geocentric and heliocentric model of the universe?
Geocentric – Earth is center; Heliocentric – Sun is center
What is retrograde motion?
The apparent backwards movement of the planets
Draw and label the 8 phases of the moon.
New moon – waxing crescent – 1st quarter moon – waxing gibbous –
full moon – waning gibbous – 3rd quarter moon – waning crescent
What are the terrestrial planets? What are the Jovian planets?
Terrestrial – earth-like, rocky, small, inner planets
Jovian – Jupiter-like, gaseous, giants, outer planets
Describe contributions to astronomy of the following astronomers:
a. Ptolemy used epicycles to explain retrograde motion
b.Copernicus father of modern astronomy; heliocentric
c. Kepler 3 laws of planetary motion
d.Galileo Points of light were 4 moons of Jupiter, Venus has phases like the
moon, surface of moon isn’t smooth, use telescope for astronomy
e. Newton law of universal gravitation
6.
What is the shape of the planets’ orbits? What are Kepler’s
3 Laws and how do they apply to the orbits of planets?
Ellipse; Law of Ellipses, Law of Equal Areas, Law of Orbital Velocities
7.
What is the Doppler Effect? And what can it tell astronomers?
Doppler Effect is the change in frequency of a wave based on the relative location of an observer.
(Think ambulance zooming by – how does the siren sound?) Astronomers use the change of
frequency in waves to determine objects’ distance from Earth.
What are the different layers of the sun?
Corona, Chromosphere, Photosphere, Solar Interior
What is the composition of the sun?
Hydrogen & helium
What are the characteristics of sunspots?
Cooler than surrounding surface
What is the source of the sun’s energy?
Nuclear fusion
What do light-years measure?
Distance light travels in one year
Describe the Nebular Theory.
Particles of dust and debris in space floating around came together under the force of gravity to form
planets and other objects in space.
Provide evidence for an expanding universe.
Red-Shift means an object is moving away from the observer.
What is the “Big Bang” theory? What does it try to explain? What are two pieces of evidence for it?
The Big Bang Theory is a possible explanation of how the universe was formed. All matter ever
contained in the universe was condensed into a ball as small as a marble. It exploded outward in
total darkness because there was no light yet and continued to spread and provide the raw material
for planets and stars to form/
Define revolution, rotation, precession, nutation and barycenter.
On Earth, a revolution is one trip around the Sun which takes one Earth year. Rotation is a
complete turn on Earth’s axis which takes approx. 24 hours (day and night). Precession is the change
in the direction of the Earth’s axis (think about a spinning top). Nutation is the slight wobbling in the
8.
9.
10.
11.
12.
13.
14.
15.
16.
Earth’s axis as it rotates. Barycenter is the center of mass between two objects in space (think seesaw).
17. What are the 4 main areas of Earth Science?
Astronomy, Geology, Meteorology, Oceanography
18. List the steps of the scientific method in order.
Ask a question. Research your subject. Develop a hypothesis. Perform an experiment. Analyze your
data. Draw a conclusion and communicate it.
19. What is a control?
Part of the experiment you don’t change so you know what normal is supposed to look like.
20. What is a variable?
Anything that changes (varies) in the experiment.
21. What is the difference between an independent and dependent variable?
Independent is the one I change. Dependent is the thing that changes as a result.
22. What is a hypothesis?
An educated guess
23. Describe contour lines, include the terms relief and contour interval.
Lines that show equal elevation on a topographic map; relief is a raised part on a map; contour interval
is the change in elevation between each contour line (this is given on the map).
24. Differentiate between latitude and longitude. Include reference from the prime meridian and equator.
Lines of latitude run E-W and are measured N and S of the equator. Lines of longitude run N-S and
are measured E-W of the Prime Meridian which runs through Greenwich, England.
25. Explain what it means when contour lines are close together or far apart.
Close together – steep slope; far apart – gentle slope
26. What is a rock? What are they made of?
A rock is any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet. Made of
minerals.
27. What are the 3 different types of rocks
and how does each form?
Magma cools and crystallizes to form igneous
rock. Igneous rock weathers and erodes to
form sediments which undergo compaction
and cementation to form sedimentary rocks.
Sedimentary rocks undergo heat and pressure
(or hydrothermal solutions) to form
metamorphic rock which melts to form
magma.
28. What is the difference between an
intrusive and extrusive rock?
Intrusive formed inside the Earth and
extrusive formed on the surface.
29. Label the rock cycle diagram.
See diagram
30. What is porphyritic texture?
Rocks with very different-size minerals experience
different rates of cooling. These rocks have a porphyritic texture.
31. What are the major components of soil?
Soil has four major components: mineral matter, or broken-down rock;
organic matter, or humus, which is the decayed remains of organisms;
water; and air.
32. What is the difference between mechanical and chemical weathering?
Physical weathering occurs when physical forces break rock into smaller and smaller pieces without
changing the rock’s mineral composition. Chemical weathering is the transformation of rock into one
or more new compounds.
33. What are the 4 factors that determine the rate of weathering?
Mechanical weathering affects the rate of chemical weathering. By
breaking rock into smaller pieces, mechanical weathering accelerates
chemical weathering by increasing the surface area of exposed rock.
Two other factors that affect the rate of weathering are rock
characteristics and climate.
34. Define erosion and list at least 4 agents of erosion.
Water, wind, glaciers and gravity move soil from one place to
another.
35. In a soil profile, what is found in the following layers:
a. A horizon topsoil
b. B horizon subsoil
c. C horizon partially weathered parent material
d. Below A, B, C bedrock/unweathered parent material
36.
Be able to use a soil texture triangle to determine the
percentages of silt, sand and clay in soil.
37. Describe how Pangaea and Continental Drift are related.
Wegener’s Theory of Continental Drift said that all land on Earth used to be together as one giant
continent called Pangaea. The Pangaea split up and the pieces drifted to their present locations.
38. What are the 4 pieces of evidence supporting Continental Drift?
South America and Africa fit together like
puzzle pieces, similar fossils found on
Crust
continents now an ocean apart, mountain
Mantle
ranges that were one continuous, and similar
climate evidence.
Outer Core
39. Describe the theory of plate tectonics.
Inner Core
The uppermost mantle and the crust behave
as a strong rigid layer called the lithosphere.
The lower mantle is called the
asthenosphere. The lithosphere is broken up
into plates which move over the
asthenosphere. There are 7 major and 7 minor plates.
40. What are the 4 main layers of Earth?
Crust, Mantle, Outer Core, Inner Core
41. Define Lithosphere and Asthenosphere.
See #39
42. What are the different types of plate boundaries and what processes occur at each boundary?
Divergent – seafloor spreading; convergent – subduction; Transform fault – plates slide past each other
43. Define subduction. At what type(s) of plate boundaries does subduction occur?
The denser oceanic plate dives down under the lighter continental plate and drives down into the
mantle until it melts and forms magma. Subduction occurs at convergent oceanic-continental
boundaries.
44. Where does sea-floor spreading occur? What is happening where the sea floor is spreading?
Sea-floor spreading occurs at oceanic-oceanic divergent boundaries. The plates move apart and
magma rises up from the mantle. When it reaches the surface, it cools and hardens forming new ocean
crust.
45. What layer of the Earth are the plates composed of?
Plates are made of lithosphere (crust and upper mantle).
46. What can paleomagnetic rocks tell us? What does the magnetic striping along ocean
floor indicate?
Paleomagnetism tells us which way the magnetic poles were
facing when the rock formed. Because we know
approximately when the poles reversed, we can determine
the age of the sea floor. The magnetic stripes occurred every
time the magnetic poles reversed direction.
47. What is a seismograph? Seismogram? Richter Scale?
A seismograph is a machine used to record the vibrations
from and earthquake. A seismogram is the strip of paper
that gives us the actual results. The Richter Scale is a way to
measure the intensity and magnitude of an earthquake using
the amplitude of the seismic waves (think the height of the waves).
48. Define epicenter, focus, and fault.
Epicenter is the point on the surface of the Earth directly above where the actual earthquake took place.
The focus is the spot deep within the Earth where the earthquake actually took place. Fault is a crack
in the Earth were movement has occurred.
49. How are earthquakes related to plate tectonics?
Earthquakes tend to happen along tectonic plate boundaries where there is the most movement.
50. How does a tsunami form?
A tsunami triggered by an earthquake occurs where a slab of the ocean floor is displaced vertically
along a fault. A tsunami also can occur when the vibration of a quake sets an underwater landslide into
motion.
51. List and Describe the 3 types of volcanoes. Give an example of each type of volcano.
Shield volcanoes – Hawaii; cinder cones – near Flagstaff Arizona, Mt. Etna; composite cones – Andes
Mountains in S. America and the Cascades in the Pacific Northwest
52. Explosive volcanoes have _high____ gas, _high____ silica, and _high____ viscosity.
53. Define tephra and compare the size of volcanic ash, lapilli and volcanic bombs.
Tephra is anything ejected from volcanoes. Volcanic ash is the smallest particle, Lapilli are also called
cinders about 2-64 mm wide; volcanic bombs are particles larger than 64 mm in size and are ejected as
glowing lava.
54. Define seismic waves and describe each type.
Waves produced by earthquakes – 2 types: surface and body waves. There are 2 types of body waves
– P-waves and S-waves. P-waves are the fastest and can travel through solids, liquids and gasses. Swaves are the second to arrive and can only travel through solids. They are called body waves because
the both travel through the body of the Earth. Surface waves travel on the surface and do the most
damage.
55. Explain the elastic rebound theory.
When rocks are deformed, they first bend and then break, releasing stored energy
56. Explain the difference between the P-wave and the S-wave.
See #54.
57. Explain the number of seismic stations needed to determine the location of the epicenter and why.
You need 3 stations to triangulate the location of an earthquake.