# Earthquake Engineering Questions and Answers – Fault Rupture Parameters

This set of Earthquake Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Fault Rupture Parameters”.

1. How many earthquakes were studied by Wells and Coppersmith to find the correlations of fault rupture parameters?
a) 55
b) 125
c) 216
d) 333

Explanation: Wells and Coppersmith studied 216 worldwide past earthquakes to find the correlations between the fault rupture parameters and judge the future earthquake possibility in an area. On the basis of these earthquakes they derived a relationship between moment magnitude and fault rupture parameters.

2. Which of the following is a fault rupture parameter?
a) Displacement
b) Shear force
c) Density
d) Height

Explanation: Out of the options available, only displacement is a fault rupture parameter. Average surface displacement and maximum surface displacement are the 2 types of displacements whose relation with moment magnitude is determined. Other fault rupture parameters are Rupture length, rupture width and rupture area.

3. Maximum surface displacement per event is double the average surface displacement per event.
a) False
b) True

Explanation: As per the study carried out by Wells and Coppersmith, the average surface displacement per event is around 50% of the maximum surface displacement. Therefore, the maximum surface displacement per event is double the average surface displacement per event.

4. Which of the following is true for average surface displacement Da?
a) It gives the average displacement along the length of rupture
b) It gives the maximum displacement along the length of rupture
c) It gives the average displacement along the height of rupture
d) It gives the maximum displacement along the height of rupture

Explanation: The average surface displacement Da denotes the average displacement along the length of rupture. The relation between moment magnitude and average surface displacement is as follows,
MW = 0.82 log(Da) + 6.93 ± 0.39
Where, MW is the moment magnitude and Da is the average surface displacement.

5. Who gave the relationship between fault rupture parameters and moment magnitude?
a) Campbell and Cornell
b) Richter and Freeman
c) Newmark and Hall
d) Wells and Coppersmith

Explanation: Based on the 216 past earthquake data, a correlation between fault rupture parameters and moment magnitude MW was given by Wells and Coppersmith. The fault rupture parameters included surface rupture length, rupture area, down-dip rupture with and displacements. Other authors who worked on these relationships were Tocher and Slemmons.

6. The relation between moment magnitude and which of the following parameter is not available?
a) Down-dip rupture width
b) Rupture area
c) surface rupture length
d) Surface rupture depth

Explanation: Relations between moment magnitude and various fault rupture parameters like rupture area, down-dip rupture width, surface rupture length, maximum surface displacement and average surface displacement is available. There is no relation between the moment magnitude and rupture depth.

7. What is the ratio of subsurface rupture length to the surface rupture length?
a) 1
b) 0.75
c) 1.25
d) 1.33

Explanation: After studying the fault rupture parameters it was concluded that the surface rupture length is equal to 75% of the subsurface rupture length. This was the conclusion of study conducted by Wells and Coppersmith. Therefore, the ratio of subsurface rupture length to the surface rupture length is 1.33.

8. Slip is initiated at which point on the fault plane?
a) Epicenter
b) Hypocenter
c) Site
d) Hanging wall

Explanation: Hypocenter is the point at which the earthquake originates. It is the point at which the slip is instigated on the fault plane. Epicenter is the point on the earth’s surface exactly above the hypocenter. Site is the location under consideration. When the rocks slip past each other in faulting, the upper block along the fault plane is known as hanging wall.

Sanfoundry Global Education & Learning Series – Earthquake Engineering.