# Earthquake Engineering Questions and Answers – Classification of Earthquakes

This set of Earthquake Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Classification of Earthquakes”.

1. Earthquakes occurring as a result of movement of rocks because of geological changes are called as ____________________
a) Tectonic earthquake
b) Volcanic earthquake
c) Explosive earthquake
d) Collapse earthquake

Explanation: The geological changes under the ground surface result in the movement of tectonic plates which may cause tectonic earthquakes. Depending upon the location of the fault in a tectonic plate, the earthquakes are further classified as interplate and intra-plate earthquake.

2. When the earthquake occurs at the boundary of two tectonic plates it is called as ____________
a) Intraplate earthquake
b) Interplate earthquake
c) Interionic earthquake
d) Teleseismic earthquake

Explanation: When an earthquake occurs at the boundary of two tectonic plates it is called as an interplate earthquake whereas if it occurs in the interior of the plate it is called as an intraplate earthquake.

3. Intensity of interplate earthquake is ____________ intraplate earthquake.
a) More than
b) Less than
c) Same as
d) Independent of

Explanation: In an intraplate earthquake the tectonic plates release seismic stress gradually whereas in an interplate earthquake the tectonic plates release energy suddenly and concentrated at the boundaries. Hence, the stress drop in an intraplate earthquake is more resulting in greater intensity.

4. In intraplate earthquake the stress is concentrated along the boundaries.
a) True
b) False

Explanation: Intraplate earthquake occur as a result of stress concentration in the interior of the plate whereas inter-plate earthquakes occur as a result of stress concentration along the boundaries.

5. The intraplate earthquakes release energy gradually.
a) True
b) False

Explanation: The tectonic plates that result in an intra-plate earthquake are strong and coherent from interior than the boundaries. Hence the seismic energy is transmitted from the interior of the plate towards the exterior boundaries at a very slow rate.

6. The frequency of occurrence of intraplate earthquake is _________ than interplate earthquake.
a) 90% less than
b) 90% more than
c) Same as
d) 30% less than

Explanation: The earth is made up of seven major tectonic plates and several number of minor tectonic plates. The joints between these plates is brittle and cannot sustain larger amount of seismic stress. Hence most of the faults develop across the boundaries than in the interiors, resulting in frequency of occurrence of intraplate earthquake 90% less than inter-plate earthquake.

7. The Bhuj earthquake of 2001 was which type of earthquake?
a) Interplate
b) Intraplate
c) Teleseismic
d) Unidentified

Explanation: The Bhuj earthquake was an intraplate earthquake because the epic- centre was located at a distance of about 400 Km from the plate boundary i.e. in the interior of the Kutch region.

8. In which of these faults the cross moves sideways?
a) Reverse fault
b) Normal fault
c) Transcurrent fault
d) Strike-Strike fault

Explanation: A reverse fault is formed when one block of crust slides above another. A normal fault is formed when two blocks of a crust move apart. Whereas a transcurrent fault occurs when the rocks slide horizontally with little or no vertical movement.

9. Most of the tsunamis are created because of intraplate earthquakes.
a) True
b) False

Explanation: Intraplate earthquakes result in gradual release of stress which results in release of seismic waves over long duration. They have more proximity to the seabed compared to the ground surface. Therefore, intraplate earthquakes are a major cause of Tsunamis.

10. Which of these earthquakes has the lowest frequency and can be picked up only by a seismometer?
a) Iso-seismal earthquake
b) Teleseismic earthquake
c) Local earthquake
d) Regional earthquake

Explanation: Teleseismic earthquakes are the ones which occur at a distance of 500 Km from the epicentre. Their intensity is so small that they can only be detected by seismometers.

Sanfoundry Global Education & Learning Series – Earthquake Engineering.

To practice all areas of Earthquake Engineering, here is complete set of Multiple Choice Questions and Answers.

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