NAME___________________________________ Core Geology 3.32
1. The scientific study of earthquakes and seismic waves is known as _______.
A) seismograph
B) seismogram
C) seismology
D) vulcanology
E) tectonics
2. Fragments of unmelted rocks that are sometimes incorporated in magma are known as
_______.
A) iron meteorites
B) kimberlites
C) volcanic bombs
D) tsunamis
E) xenoliths
3. _______ are the first waves to leave the focus after an earthquake.
A) P-waves
B) S-waves
C) surface waves
D) body waves
E) shear waves
4. The _______ is the part of the Earth's interior where rocks start to melt.
A) lithosphere
B) asthenosphere
C) outer core
D) inner core
E) crust
5. A _______ wave is an elastic rebound wave that travels outward in all directions from the
point of an earthquake.
A) shear
B) body
C) surface
D) Mercalli
E) seismic
For questions 6 and 7 refer to the figure below:
6. In the figure above, what is the approximate time of the arrival of the P-waves?
A) 1 minute
B) 2 minutes, 15 seconds
C) 3 minutes
D) 4 minutes
E) 5 minutes, 30 seconds
7. According to the figure above, what is the approximate S-P travel time?
A) 1 minute, 45 seconds
B) 2 minutes, 15 seconds
C) 3 minutes, 15 seconds
D) 0 minutes, 45 seconds
E) cannot be determined
True/False
8. The Earth's density as a whole is approximately 2.8 g/cm3.F
9. P-waves travel by compression-expansion. T
10. The mantle makes up roughly 80% of the Earth's volume. T
Fill-In-The-Blank
11. A large, destructive wave sometimes caused by am earthquake is called a _______.
TSUNAMI
12. _______ is the bouncing back of a wave from an interface between two mediums.
REFLECTION
13. The theory that stress is continually built up along a fault and released when earthquake
occurs is known as _______.
ELASTIC REBOUND
14. The method of using data from three seismic stations to locate an earthquake is known as
_______.
TRIANGULATION
15. _______ are fragments of unmelted rock that are sometimes incorporated in magma.
XENOLITHS
16. The area inside the Earth where rocks start to turn plastic is known as the _______.
ASTHENOSPHERE
17. In the figure below, what is the approximate speed of S-waves and the P-waves as the
earthquake starts?
A)
B)
C)
D)
E)
2km/sec and 4km/sec
6km/sec and 3km/sec
10km/sec and 2km/sec
4km/sec and 6km/sec
8km/sec and 10km/sec
Short Essay
18. Describe the method of triangulation.
Having seismograms from three different stations we could see the arrival of the P-wave and the
S-wave and from there we could determine the S-P interval. Once we have these data then using
the graph of S-P interval against distance we could determine the radius in miles or kilometers
from the epicenter to the respective station and tracing these three circles, one per each station
we could determine the epicenter (where the three circles meet).
19. In the figure below, how does the location of the largest earthquakes correlate with plate
boundaries?
All these earthquakes happen to indicate the boundary of a plate, also knowing that the most
powerful earthquakes are located at subduction zones, we could infer that these volcanoes point
to convergent type boundaries.