Civil Engineering Reference
In-Depth Information
APPENDIX E
SOLUTIONS TO PROBLEMS
CHAPTER 2
2.1
Since the fault has moved solely in the dip direction, it is termed a
dip-slip
fault.
Because the hanging wall block has moved upward with respect to the foot wall
block, the fault is either a reverse fault or a thrust fault. Based on the orientation of the
fault plane (5 NW, 34 W), the dip of the fault plane is 34°. Thrust faults are defined as
having a dip that is less than or equal to 45°, and therefore the fault is termed a
dip-slip
thrust fault.
2.2
In Fig. 2.21, the hanging wall block has moved downward with respect to the
foot wall block. The fault is thus termed a
normal fault.
2.3
From Fig. 2.14, the maximum displacement recorded by the seismograph is 14.9
cm. Assuming this displacement represents the trace data from a standard Wood-Anderson
seismograph and that the instrument is exactly 100 km from the epicenter, then
A
14.9
cm
149 mm. Using Eq. (2.1) with
A
0
0.001 mm gives
M
L
log
A
A
0
log
149
___
_____
0.001
5.2
2.4
Circumference of the earth
4.0
10
7
m (360°)
Distance to seismograph
1200 km
1.2
10
6
m
1.2
10
6
________
4.0
10
7
(360°)
10.8°
Using Eq. (2.2) and
A
15.6 mm
15,600
m gives
M
s
log
A
1.66 log
2.0
log 15,600
1.66 log 10.8
2.0
7.9
2.5
Use Eq. (2.3)
M
0
A
f
D
E.1
