GEOL 118-02: Physical Geology
Homework #2: Earth’s Interior & Earthquakes (20 points)
Scientists can use seismic data to determine the focus of earthquakes within the Earth. The
location data for earthquakes can help us to learn about the structure of the Earth’s subsurface.
The data contained within the table below show represent the depth of focus for numerous
earthquakes as well as the distance of these earthquakes from a nearby convergent margin.
Sequence
Depth Below
Surface (km)
Depth from Convergent
Margin (km)
EQ1
430
575
EQ2
380
460
EQ3
430
620
EQ4
550
690
EQ5
175
320
EQ6
25
70
EQ7
640
760
EQ8
300
380
EQ9
115
195
EQ10
325
500
EQ11
360
420
EQ12
205
390
EQ13
510
670
EQ14
100
155
EQ15
655
755
(1) Graph the data provided in the table above on the blank chart on the next page. Place a
●
at
the location of each earthquake’s focus. When completed, draw a straight line through the
data to indicate the general trend of the data. (6 points)
(2) What is the name of the geologic feature you have just plotted? (2 points)
(3) Using the line that you drew through your data points, predict the depth below the surface of
an earthquake measured to be
550 km
from the convergent margin. (2 points)
(4) What does this geologic feature indicate about the processes occurring in the subsurface? Be
specific, and relate your answer to global-scale processes. (2 points)
