Download Quiz 3 Study Guide

Geology 107 – Study Guide for Quiz 3
Study Guide covers Structural Geology, Earthquakes, and Plate Tectonics
1. Label the Anticlines and Synclines on the following Block Diagram. Label the layers from oldest to
youngest on all three sides of the diagram. Be sure to label the oldest as 1 (since it was the 1st to be
deposited):
2. Label the strike, dip direction (Dip), and dip angle (Dip ) for each of the following:
N
NNW
NNE
NW
50
30
62
44
NE
ENE
WNW
W
E
WSW
Strike:
Dip:
Dip :
Strike:
Dip:
Dip :
Strike:
Dip:
Dip :
Strike:
Dip:
Dip :
ESE
SW
SE
SSW
12
80
5
66
Strike:
Dip:
Dip :
Strike:
Dip:
Dip :
Strike:
Dip:
Dip :
Strike:
Dip:
Dip :
25
Strike:
Dip:
Dip :
Remember: Dip Direction is ALWAYS perpendicular to strike!
(regardless of the wacky way it forced me to draw some of the little dip marks)
S
SSE
3. Label the block diagrams with at least three layers:
I will include some additional small blocks below in case you want to practice or if you make a mistake
above and need to re-draw.
4. What kind of fault is shown in the following diagrams? Justify your answer for each. Label the
footwall and hanging wall where appropriate.
5. Label the P-Wave, S-Wave, and Surface Waves on the following seismogram:
6. Based on the location of the Modified Mercalli intensity values, where is the most likely location of
the earthquake? (For hint, see Earthquakes powerpoint slide about Exercise 16.6)
7. Use the travel-time chart below to answer the following questions (estimate time to the nearest
quarter minute).
What is the seismometer’s distance from the earthquake’s epicenter if the S-P interval is:
a) 1 minute:
b) 2 minutes:
c) 3 minutes:
d) 4 minutes:
How long did it take for the P-wave to arrive if distance from the epicenter is:
a) 2000 km:
b) 1500 km:
c) 900 km:
d) 400 km:
How far away from the epicenter is the seismometer if it the P-wave took:
a) 5 minutes to arrive?
b) 6 minutes to arrive?
c) 5 minutes and 30 seconds to arrive?
d) 30 seconds to arrive?
S-Wave
P-Wave
8. Use the following Richter Magnitude scale below to answer the following questions. Show on the
chart how you arrived at your answer.
What is an earthquake’s magnitude on the Richter scale if:
a) a wave amplitude of 1 mm was experienced at a distance of 400 km?
b) a wave amplitude of 200 mm was experienced at a distance of 700 km?
c) a wave amplitude of .1 mm was experienced at a distance of 60 km?
d) a wave amplitude of 10 mm was experienced at a distance of 20 km?
e) a wave amplitude of 500 mm was experienced at a distance of 300 km?
9. Triangulate the location of an earthquake’s epicenter using the distances provided.
a) Distance from epicenter:
Rome = 300 km
Kiev = 550 km
London = 850 km
b) Distance from epicenter:
Oslo = 400 km
Reykjavik = 1050 km
Madrid = 550 km
10. Use the plate tectonic map on the next page to answer the following questions.
a) What type of plate boundary is the Mid-Atlantic Ridge?
b) What type or types of crust compose the South American Plate?
c) Is there a plate boundary along the eastern coastline of South America? If so, what type?
d) What type of plate boundary exists between southern Spain (labeled) and northern Africa?
e) What type of plate boundary lies along the Aleutian Islands (labeled—southwest of Alaska along the
border of the Pacific and North American plates)?
f) What geologic activity would you expect to find along the Aleutian Islands?
g) Are Antarctica and Australia growing farther apart or closer together? Justify your answer.
h) What type of boundary exists in the Middle East along the northeast border of the Arabian plate
(adjacent to the Eurasian plate)? What type of lithosphere is each plate composed of along the
boundary?
i) If you lived in Siberia (labeled—on the Eurasian plate in Eastern Russia), would you expect to
experience many high magnitude earthquakes? Why or why not?
j) If you lived in Japan (labeled just east of Siberia), would you expect to experience many high
magnitude earthquakes? Why or why not?
Divergent Boundary
Convergent Boundary
Transform Boundary
Aleutian
Islands
Siberia
Japan
Spain
11. On the following diagram, label the (1) direction of plate movement, (2) fault plane, (3) sea trench,
(4) island arc, (5) subducted lithosphere, (6) where earthquakes occur, (7) where melting of the
subducted plate occurs, and (8) where you would expect rising magma to exist.
12. The following map shows hot spot activity in southern Idaho and Yellowstone National Park. There
is an active mantle plume under the earth at Yellowstone and it has created a chain of volcanoes on
the landscape over at least the past 16 million years. The hot spot is currently below Yellowstone
Park (under the Yellowstone Caldera on the map—a caldera is a bowl-shaped structure above the
core of an ancient volcano that collapsed after it erupted). (Ma = “million years ago”)
a) What is the direction of plate movement?
b) What is the difference in time between the oldest and youngest caldera?
If the true distance (curved dashed line) between the youngest caldera and the oldest caldera is 300 km,
what is the rate of movement of this plate? (Show your math)
c) Answer in km/yr:
d) Answer in cm/yr:
e) Answer in mm/yr:
If the true distance (curved dashed line) between the young caldera and the oldest caldera is 550 km,
what is the rate of movement of this plate? (Show your math)
f) Answer in km/yr:
g) Answer in cm/yr:
h) Answer in mm/yr:
13. The mantle plume under the Pacific Plate has created a chain of volcanoes in the ocean—the islands
of Hawaii are a part of this chain.
a) Where is the oldest island and where is the youngest
island?
b) Which direction was the Pacific Plate moving from 70
to 40 million years ago?
c) It changed direction around 40 million years ago—
which direction is the Pacific Plate moving now?
14. Use the following magnetic anomaly diagram to answer the questions below. The stripes show the
polarity and age of rocks at a given distance westward from their spreading center (ridge). The
eastern side of the ridge would be a mirror image of this chart. (Ma = “million years old”)
a) How old are the rocks 1000 km from the ridge?
b) How old are the rocks 1750 km from the ridge?
c) How far away from the ridge are rocks dated at 15Ma?
d) How far away from the ridge are rocks dated at 48Ma?
e) How far have the rocks on both sides of the ridge spread from each other over the past 20Ma?
f) What has been the average rate of spreading in mm/yr of the entire ridge over the past 55Ma?
(Show your math)