1. What is a massive sea wave triggered primarily by an undersea earthquake called?
Correct Answer: b) Tsunami
Explanation:
A tsunami is a series of large ocean waves generated by sudden vertical displacement of the seafloor, most commonly caused by submarine earthquakes.
2. What is the principal primary cause of tsunamis worldwide?
Correct Answer: b) Underwater earthquakes
Explanation:
Subduction-zone earthquakes that rupture the sea bottom are responsible for more than 80% of all recorded tsunamis globally.
3. In which year did a catastrophic tsunami strike the Makran coastal areas of Balochistan, Pakistan?
Correct Answer: c) 1946
Explanation:
The Makran subduction zone earthquake and its deadly associated tsunami occurred in late November 1945 and continued into early 1946, devastating coastal settlements along Balochistan and Karachi.
4. From which language is the word 'Tsunami' derived?
Correct Answer: b) Japanese
Explanation:
The word 'Tsunami' comes from Japanese, combining 'tsu' (harbor) and 'nami' (wave), meaning 'harbor wave'.
5. On 26th December 2004, a massive undersea earthquake and tsunami devastated 12 countries, with its epicenter located off the coast of:
Correct Answer: a) Sumatra (Indonesia)
Explanation:
The catastrophic 2004 Indian Ocean earthquake (magnitude 9.1–9.3) had its epicenter off the western coast of northern Sumatra, Indonesia.
6. In which ocean did the massive undersea mega-thrust earthquake of December 2004 occur?
Correct Answer: b) Indian Ocean
Explanation:
The December 26, 2004 earthquake occurred along the subduction boundary beneath the Indian Ocean, triggering pan-oceanic tsunamis.
7. What are the smaller earthquakes that follow the main shock in the same general region called?
Correct Answer: c) Aftershocks
Explanation:
Aftershocks are secondary earthquakes that occur in the same area as the larger mainshock as the ruptured crust adjusts to the stress displacement.
8. On which date was the historic city of Quetta devastated by a massive earthquake that killed over 30,000 people?
Correct Answer: a) 31 May 1935
Explanation:
The 1935 Quetta earthquake struck Balochistan on 31 May 1935, nearly destroying the entire city and killing tens of thousands.
9. The largest earthquake recorded in the 20th century (and in recorded history) occurred on May 22, 1960, at which location?
Correct Answer: a) Valdivia, Chile
Explanation:
The 1960 Great Chilean earthquake at Valdivia registered a record magnitude of 9.5 on the moment magnitude scale.
10. On which continent did the largest recorded earthquake of the 20th century (Valdivia, 1960) occur?
Correct Answer: c) South America
Explanation:
The Valdivia earthquake occurred along the southern Chilean subduction zone on the South American continent.
11. What was the recorded magnitude on the Richter scale / moment magnitude scale of the catastrophic earthquake that hit northern Pakistan on 8th October 2005?
Correct Answer: b) 7.6
Explanation:
The Kashmir earthquake of October 8, 2005, had an official moment magnitude of 7.6, causing massive devastation across Azad Kashmir and Khyber Pakhtunkhwa.
12. Which country dispatched the largest contingent of medical personnel and field hospitals to Pakistan following the 8th October 2005 earthquake?
Correct Answer: a) Cuba
Explanation:
Cuba sent over 2,400 medical doctors and paramedical personnel along with 30-plus fully equipped field hospitals to treat earthquake victims in Pakistan.
13. Which former US President visited Pakistan as the United Nations Special Envoy for South Asian Earthquake Relief after the 2005 disaster?
Correct Answer: a) George H. W. Bush (Bush Senior)
Explanation:
Former US President George H. W. Bush (Bush Senior) was appointed by the UN Secretary-General as the UN Special Envoy for Pakistan Earthquake Relief.
14. What is the point beneath Earth's surface where an earthquake's rupture begins called?
Correct Answer: b) Hypocenter (Focus)
Explanation:
The hypocenter or focus is the exact underground location along a fault plane where seismic energy is first released.
15. What is the point on Earth's surface directly vertically above the hypocenter of an earthquake called?
Correct Answer: a) Epicenter
Explanation:
The epicenter is the geographical point on the Earth's surface lying directly above the subterranean focus.
16. What instrument is used to detect, measure, and record the ground motions produced by seismic waves?
Correct Answer: b) Seismograph (Seismometer)
Explanation:
A seismograph is an instrument that detects and records vibrations caused by seismic waves travelling through the Earth.
17. What is the physical graphical record of ground motion produced by a seismograph called?
Correct Answer: a) Seismogram
Explanation:
The paper chart or digital data recording of seismic wave signals is termed a seismogram.
18. The science that deals with the study of earthquakes and the propagation of elastic seismic waves through the Earth is called:
Correct Answer: b) Seismology
Explanation:
Seismology is the branch of geophysics devoted to the scientific investigation of earthquakes and mechanical wave transmission through planetary interiors.
19. Which seismic wave travels the fastest and is always the first to arrive at a seismic recording station?
Correct Answer: b) Primary wave (P-wave)
Explanation:
Primary (P) waves are compressional longitudinal body waves that propagate faster than all other seismic wave types through rock.
20. Secondary waves (S-waves) are shear waves that can travel through which states of matter?
Correct Answer: a) Solids only
Explanation:
S-waves propagate via perpendicular shear motion, which fluids (liquids and gases) cannot support because they lack shear strength.
21. Which type of seismic waves cause the most destructive horizontal and vertical surface ground displacement during an earthquake?
Correct Answer: a) Surface waves (Love and Rayleigh waves)
Explanation:
Surface waves travel along the Earth's crust with large amplitudes and longer durations, making them the primary cause of structural damage.
22. The Richter magnitude scale, developed by Charles Richter in 1935, is mathematically based on what type of scale?
Correct Answer: b) Logarithmic scale
Explanation:
The Richter scale is base-10 logarithmic, meaning each whole number increase represents a tenfold increase in measured wave amplitude.
23. For each whole-number increase in earthquake magnitude on a moment/Richter scale, approximately how much more seismic energy is released?
Correct Answer: b) 32 times
Explanation:
A magnitude increase of 1.0 corresponds to an approximate 31.6-fold (roughly 32 times) increase in the amount of total energy released.
24. Which scale measures the observed intensity and damage effects of an earthquake on people, structures, and the natural landscape?
Correct Answer: a) Modified Mercalli Intensity (MMI) scale
Explanation:
The Modified Mercalli Intensity scale evaluates earthquake severity qualitatively using Roman numerals from I (not felt) to XII (total destruction).
25. What is the maximum rating on the Modified Mercalli Intensity (MMI) scale?
Correct Answer: b) XII
Explanation:
The Mercalli scale ranges from Roman numeral I (imperceptible) up to XII (complete catastrophic devastation).
26. Which modern scale is universally preferred by seismologists to measure large-magnitude earthquakes based on total fault slip area and displacement?
Correct Answer: a) Moment Magnitude Scale (Mw)
Explanation:
The Moment Magnitude scale (Mw) calculates the seismic moment directly from fault area, slip distance, and rock rigidity without saturating on large events.
27. Which major earthquake zone circles the Pacific Ocean basin and accounts for over 80% of the world's largest earthquakes?
Correct Answer: c) Circum-Pacific Belt (Ring of Fire)
Explanation:
The Circum-Pacific seismic belt (Pacific Ring of Fire) is home to extensive subduction zones responsible for the vast majority of seismic and volcanic events.
28. Which seismic belt extends from the Mediterranean through the Middle East, Iran, Pakistan, and the Himalayas into Southeast Asia?
Correct Answer: a) Alpide / Alpine-Himalayan Belt
Explanation:
The Alpide belt is created by the ongoing continental collision of the African, Arabian, and Indian plates with Eurasia, generating about 15% of global earthquakes.
29. What is the phenomenon where water-saturated sandy soil temporarily loses its strength and behaves like a liquid during strong seismic shaking?
Correct Answer: a) Soil liquefaction
Explanation:
Liquefaction occurs when cyclic seismic stresses increase pore-water pressure in unconsolidated sediment, causing buildings to sink or tilt.
30. Which famous transform fault in California marks the boundary between the Pacific Plate and the North American Plate?
Correct Answer: a) San Andreas Fault
Explanation:
The San Andreas Fault is a right-lateral strike-slip fault that extends roughly 1,200 km through California.
31. The Great San Francisco Earthquake that triggered widespread citywide fires occurred in which year?
Correct Answer: b) 1906
Explanation:
On April 18, 1906, an estimated 7.9 magnitude earthquake ruptured the San Andreas Fault, destroying San Francisco largely through post-quake fires.
32. The 1923 Great Kanto earthquake destroyed Tokyo and Yokohama on which continent?
Correct Answer: a) Asia (Japan)
Explanation:
The Great Kanto earthquake struck the main Japanese island of Honshu on September 1, 1923, resulting in more than 140,000 deaths.
33. The deadliest earthquake in human history in terms of total fatalities is believed to have struck Shaanxi, China, in which year?
Correct Answer: a) 1556
Explanation:
The 1556 Shaanxi earthquake in Ming dynasty China resulted in an estimated 830,000 deaths, mostly due to the collapse of loess cave dwellings (yaodongs).
34. The 1976 Tangshan earthquake, one of the deadliest 20th-century seismic catastrophes, occurred in which country?
Correct Answer: a) China
Explanation:
The Tangshan earthquake struck Hebei province, China, on July 28, 1976, causing an official death toll of approximately 242,000.
35. The historic 1755 Lisbon earthquake, which sparked major philosophical debates during the European Enlightenment, struck which country?
Correct Answer: a) Portugal
Explanation:
The Great Lisbon earthquake occurred on All Saints' Day (November 1, 1755), destroying Lisbon through shaking, tsunamis, and fire.
36. On March 11, 2011, a colossal 9.0–9.1 magnitude earthquake struck northeastern Japan, triggering the meltdown at which nuclear power facility?
Correct Answer: a) Fukushima Daiichi
Explanation:
The Great East Japan (Tohoku) earthquake and tsunami flooded the backup generators at Fukushima Daiichi nuclear plant, triggering core meltdowns.
37. What is the tectonic mechanism responsible for the ongoing uplift and severe seismicity of northern Pakistan and the Himalayas?
Correct Answer: a) Collision of the Indian Plate with the Eurasian Plate
Explanation:
The northward collision of the Indian tectonic plate into the Eurasian plate at ~4-5 cm/year generates intense crustal stresses and major Himalayan earthquakes.
38. The city of Muzaffarabad was located near the epicenter of which catastrophic historical earthquake?
Correct Answer: a) 8th October 2005 Kashmir Earthquake
Explanation:
Muzaffarabad, the capital of Azad Jammu and Kashmir, was situated just 19 km from the epicenter of the 2005 magnitude 7.6 earthquake.
39. Which active geological fault line in northern Pakistan ruptured during the October 8, 2005 earthquake?
Correct Answer: a) Balakot-Bagh Fault (Main Boundary Thrust zone)
Explanation:
The 2005 earthquake ruptured the Balakot-Bagh fault segment over a length of approximately 75 kilometers.
40. The prominent left-lateral transform fault running through western Pakistan and eastern Afghanistan is known as the:
Correct Answer: a) Chaman Fault
Explanation:
The Chaman Fault System is a major active transform fault accommodating relative motion between the Indian and Eurasian plates.
41. The Makran Subduction Zone in the northern Arabian Sea forms the convergent boundary between the Eurasian Plate and the:
Correct Answer: a) Arabian Plate
Explanation:
In the Makran region off the coast of Pakistan and Iran, the oceanic crust of the Arabian plate subducts northward beneath Eurasia.
42. In September 2013, an earthquake of magnitude 7.7 struck which district in southwestern Balochistan, creating a temporary mud island in the Arabian Sea?
Correct Answer: a) Awaran
Explanation:
The September 24, 2013 Awaran earthquake triggered a mud volcano that formed a transient offshore island named 'Zalzala Koh' near Gwadar.
43. In December 1974, a destructive magnitude 6.2 earthquake struck which town along the Karakoram Highway in northern Pakistan?
Correct Answer: a) Pattan (Hunza-Hazara region)
Explanation:
The 1974 Pattan earthquake destroyed the town of Pattan in Khyber Pakhtunkhwa, killing over 5,000 people.
44. Which authority was established by the Government of Pakistan specifically for rehabilitation and reconstruction following the 2005 earthquake?
Correct Answer: a) ERRA (Earthquake Reconstruction and Rehabilitation Authority)
Explanation:
ERRA was established in 2005 to plan, coordinate, and execute long-term post-earthquake rebuilding in affected areas.
45. The catastrophic earthquake of January 12, 2010 (magnitude 7.0) devastated which Caribbean capital city, killing over 200,000 people?
Correct Answer: a) Port-au-Prince (Haiti)
Explanation:
The 2010 Haiti earthquake struck near the densely populated capital Port-au-Prince with extreme shallow focus destruction.
46. In February 2023, massive twin earthquakes of magnitude 7.8 and 7.5 caused widespread destruction in southern Türkiye and northern:
Correct Answer: a) Syria
Explanation:
The Kahramanmaraş earthquakes on February 6, 2023, caused massive casualties across southern Türkiye and northern Syria.
47. Which major strike-slip fault system in Anatolia ruptured during the February 2023 Turkish-Syrian earthquake disaster?
Correct Answer: a) East Anatolian Fault Zone
Explanation:
The 2023 earthquakes ruptured segments of the East Anatolian Fault and related branches at the junction of the Anatolian and Arabian plates.
48. Which fault zone running across northern Türkiye was responsible for the devastating 1999 İzmit (Kocaeli) earthquake?
Correct Answer: a) North Anatolian Fault (NAF)
Explanation:
The North Anatolian Fault is a major right-lateral strike-slip fault running parallel to the Black Sea coast.
49. The January 2001 Gujarat (Bhuj) earthquake that killed roughly 20,000 people occurred on which national holiday in India?
Correct Answer: a) Republic Day (26th January)
Explanation:
The Bhuj intraplate earthquake (Mw 7.7) occurred on the morning of Indian Republic Day, January 26, 2001.
50. In April 2015, a magnitude 7.8 earthquake named the Gorkha earthquake devastated which Himalayan country?
Correct Answer: a) Nepal
Explanation:
The Gorkha earthquake struck central Nepal on April 25, 2015, destroying historic monuments in Kathmandu and triggering avalanches on Everest.
51. The second-largest earthquake ever instrumentally recorded was the 1964 Great Alaska earthquake, which had a magnitude of:
Correct Answer: a) 9.2
Explanation:
The Prince William Sound (Good Friday) earthquake struck Alaska on March 27, 1964, with a magnitude of 9.2.
52. In December 2003, a shallow magnitude 6.6 earthquake destroyed the ancient adobe citadel of Arg-e Bam in which country?
Correct Answer: a) Iran
Explanation:
The 2003 Bam earthquake in southeastern Iran killed over 26,000 people and destroyed the world's largest adobe building complex.
53. What is an earthquake that occurs within the interior of a tectonic plate, away from plate boundaries, called?
Correct Answer: a) Intraplate earthquake
Explanation:
Intraplate earthquakes (such as the New Madrid 1811-1812 quakes or Bhuj 2001) occur within stable continental interiors.
54. The elastic-rebound theory, explaining how energy builds up through strain and is released as an earthquake, was formulated by:
Correct Answer: a) Harry Fielding Reid
Explanation:
Reid proposed the elastic rebound theory after studying crustal displacement following the 1906 San Francisco earthquake.
55. What is the boundary between the Earth's crust and the underlying mantle, discovered via seismic wave refraction, called?
Correct Answer: a) Mohorovičić discontinuity (Moho)
Explanation:
Croatian seismologist Andrija Mohorovičić discovered the crust-mantle boundary (Moho) in 1909 based on sudden increases in seismic wave velocities.
56. Which seismic discontinuity marks the boundary between the solid mantle and the liquid outer core?
Correct Answer: a) Gutenberg discontinuity
Explanation:
Beno Gutenberg identified the core-mantle boundary at a depth of ~2,900 km, where S-waves cease and P-waves refract sharply.
57. Who discovered in 1936 that the Earth possesses a solid inner core using seismic P-wave reflections?
Correct Answer: a) Inge Lehmann
Explanation:
Danish seismologist Inge Lehmann analyzed seismograms of New Zealand earthquakes to prove the existence of Earth's solid inner core.
58. The seismic shadow zone for S-waves extends beyond which angular distance from an earthquake epicenter?
Correct Answer: a) 103° to 180°
Explanation:
Because S-waves cannot travel through the liquid outer core, an S-wave shadow zone exists on the opposite side of Earth from 103° to 180°.
59. The P-wave shadow zone on Earth's surface occurs between which epicentral angular distances?
Correct Answer: a) 103° and 142°
Explanation:
P-waves are strongly refracted downward upon entering the liquid core, creating a shadow zone on the surface between 103° and 142°.
60. What is the dipping planar zone of seismicity produced by an oceanic plate subducting beneath a continental plate called?
Correct Answer: a) Wadati-Benioff zone
Explanation:
The Wadati-Benioff zone is a band of shallow to deep-focus earthquakes tracing the path of a down-going subducting tectonic slab.
61. Deep-focus earthquakes occur at depths between 300 km and approximately what maximum depth in the mantle?
Correct Answer: a) 700 km
Explanation:
Earthquakes rarely occur deeper than ~700 km because mantle rock behaves plastically under extreme temperatures and pressures.
62. What is a cluster of small earthquakes occurring in a localized area over a short period without a distinct main shock called?
Correct Answer: a) Earthquake swarm
Explanation:
An earthquake swarm is a sequence of seismic events where no single earthquake is identifiable as the main shock, often linked to volcanic or hydrothermal fluid movement.
63. What are slow, long-period seismic slip events along a fault that release energy without generating high-frequency shaking called?
Correct Answer: a) Slow slip events (Silent earthquakes)
Explanation:
Slow slip events release significant tectonic stress over days or months without producing noticeable destructive ground shaking.
64. Earthquakes caused by human activities such as deep wastewater injection, hydraulic fracturing, or reservoir impoundment are termed:
Correct Answer: a) Induced seismicity
Explanation:
Induced seismicity refers to earthquakes triggered by human actions that alter pore fluid pressure or stress states along subsurface faults.
65. Which large dam in Maharashtra, India, was associated with a deadly induced earthquake of magnitude 6.3 in December 1967?
Correct Answer: a) Koyna Dam
Explanation:
The 1967 Koyna earthquake is one of the classic global examples of Reservoir-Triggered Seismicity (RTS).
66. In structural engineering, installing flexible rubber-and-steel bearing pads beneath building columns to decouple structures from ground motion is known as:
Correct Answer: a) Base isolation
Explanation:
Base isolation decouples a building's superstructure from its substructure, mitigating the transmission of horizontal ground acceleration.
67. A heavy spherical suspended mass installed inside skyscrapers (such as Taipei 101) to counter seismic and wind vibrations is called a:
Correct Answer: a) Tuned mass damper
Explanation:
A tuned mass damper oscillates in opposition to structural sway, reducing peak vibration amplitudes during windstorms and earthquakes.
68. What is the recommended personal safety drill during sudden earthquake shaking indoors?
Correct Answer: a) Drop, Cover, and Hold On
Explanation:
The standard emergency protocol is to Drop to the floor, take Cover under sturdy furniture, and Hold On until shaking stops.
69. Why is standing in a doorway no longer recommended as primary earthquake safety protocol in modern homes?
Correct Answer: a) Modern interior doorways are not structurally reinforced and the swinging door can cause injuries
Explanation:
Modern doorways are no stronger than other parts of a house and do not shield against flying or falling debris.
70. Which international system operates automated deep-ocean pressure sensors (tsunameters) anchored to the seabed to detect tsunamis in real time?
Correct Answer: a) DART (Deep-ocean Assessment and Reporting of Tsunamis)
Explanation:
The DART network uses bottom pressure recorders and surface buoys to transmit acoustic sea-height data via satellites for early warnings.
71. In open deep ocean water, a tsunami wave travels at speeds comparable to a commercial jetliner, roughly:
Correct Answer: a) 700 to 800 km/h
Explanation:
In water depths of 4,000 meters, tsunami waves travel at $\sqrt{gd} \approx 200\text{ m/s}$ (over 720 km/h), but with very small open-ocean wave heights.
72. What is the phenomenon called where a tsunami wave slows down and grows dramatically in height as it enters shallow coastal water?
Correct Answer: a) Wave shoaling
Explanation:
As the wave encounters shallow depths, its front slows while energy compresses, dramatically increasing wave amplitude (shoaling).
73. What natural coastal warning sign frequently precedes the arrival of the first large tsunami wave crest?
Correct Answer: a) Sudden dramatic receding of the sea water from the shoreline (drawback)
Explanation:
If the trough of a tsunami wave reaches shore first, the sea recedes rapidly, exposing the seafloor before the massive crest strikes.
74. The 1908 Messina earthquake and tsunami, Europe's most devastating historical earthquake disaster, struck which country?
Correct Answer: a) Italy (Sicily and Calabria)
Explanation:
The December 28, 1908 Messina earthquake (magnitude 7.1) and tsunami killed between 75,000 and 100,000 people in southern Italy.
75. Which magnitude 8.8 earthquake struck central Chile in February 2010, shifting regional coastal geography and triggering Pacific-wide tsunami alerts?
Correct Answer: a) 2010 Maule earthquake
Explanation:
The February 27, 2010 Maule earthquake ruptured approximately 500 km of the Nazca-South American plate boundary.
76. The 2008 Wenchuan earthquake (magnitude 7.9) caused catastrophic damage and massive landslides in which province of southwestern China?
Correct Answer: a) Sichuan
Explanation:
The Sichuan earthquake struck along the Longmenshan Fault on May 12, 2008, killing over 87,000 people.
77. Which major earthquake fault zone crosses southern New Zealand, accommodating horizontal and vertical plate motion across the Southern Alps?
Correct Answer: a) Alpine Fault
Explanation:
The Alpine Fault is a right-lateral strike-slip fault that runs almost the entire length of New Zealand's South Island.
78. The 2011 Christchurch earthquake in New Zealand (magnitude 6.2) was particularly destructive because:
Correct Answer: a) It occurred at an extremely shallow depth directly beneath the city with severe liquefaction
Explanation:
Despite moderate magnitude, the February 22, 2011 quake caused extreme ground accelerations directly under Christchurch.
79. Which earthquake scale categorizes earthquake size based on the peak ground acceleration (PGA) measured by strong-motion accelerographs?
Correct Answer: a) Shindo Scale (JMA Seismic Intensity Scale in Japan)
Explanation:
Japan's Meteorological Agency (JMA) Shindo scale measures local seismic intensity from 0 to 7 based on instrumental ground acceleration.
80. What is the study of prehistoric earthquakes preserved in rock strata, sediments, and archaeological records called?
Correct Answer: a) Paleoseismology
Explanation:
Paleoseismology investigates ancient geologic fault trenches, offset strata, and liquefaction sand blows to reconstruct historic seismic recurrence intervals.
81. A segment of an active fault that has not slipped or produced a major earthquake in an unusually long time compared to adjacent segments is called a:
Correct Answer: a) Seismic gap
Explanation:
A seismic gap is a fault zone segment known to be seismically active but currently locked, indicating high potential for future ruptures.
82. What are mysterious luminous phenomena reported in the sky or along ground surfaces before or during strong earthquakes called?
Correct Answer: a) Earthquake lights (EQL)
Explanation:
Earthquake lights are unusual atmospheric electrical luminous glows thought to be caused by piezoelectric discharges or charge release in stressed rocks.
83. Which geological feature along the Jordan Rift Valley forms a major active plate boundary fault line?
Correct Answer: a) Dead Sea Transform
Explanation:
The Dead Sea Transform fault accommodates strike-slip motion between the African and Arabian tectonic plates.
84. The 1811–1812 New Madrid earthquakes, which famously caused church bells to ring on the US East Coast and temporarily reversed the Mississippi River, occurred in:
Correct Answer: a) Central United States (Missouri/Tennessee region)
Explanation:
The New Madrid seismic zone is an ancient intraplate rift system capable of producing powerful widespread earthquakes in the US midwest.
85. Which 1989 earthquake occurred during a live broadcast of the World Series in San Francisco?
Correct Answer: a) Loma Prieta earthquake
Explanation:
The magnitude 6.9 Loma Prieta earthquake struck on October 17, 1989, collapsing a section of the Bay Bridge and Cypress Viaduct.
86. The 1994 Northridge earthquake (magnitude 6.7) in the Los Angeles area was notable because it occurred on a previously unknown:
Correct Answer: a) Blind thrust fault
Explanation:
A blind thrust fault does not reach the surface, making it invisible until it ruptures during a major earthquake.
87. Which 1995 earthquake in Japan killed over 6,000 people and led to massive updates in Japanese building codes and seismic infrastructure?
Correct Answer: a) Great Hanshin (Kobe) earthquake
Explanation:
The Kobe earthquake struck the Kansai region on January 17, 1995, causing immense damage to port facilities and highways.
88. The 1985 Mexico City earthquake (magnitude 8.0) caused disproportionate devastation despite having an epicenter 350 km away because:
Correct Answer: a) The soft lakebed clay sediments under the city amplified seismic waves through resonance
Explanation:
Ancient lake sediments underlying Mexico City dramatically resonated with the 2-second period seismic waves, destroying tall buildings.
89. Which is the most seismically active country in Europe, experiencing the highest frequency of earthquakes?
Correct Answer: a) Greece
Explanation:
Greece sits at the complex convergent junction of the African, Eurasian, and Aegean Sea microplates, making it Europe's most seismic nation.
90. Which earthquake-induced hazard occurs when shaking triggers high-speed downward movements of rock, mud, and debris on steep slopes?
Correct Answer: a) Seismic landslides / rockfalls
Explanation:
Earthquakes frequently destabilize mountain slopes, causing massive landslides that can bury villages and block rivers to form landslide lakes.
91. What is a lake created when an earthquake-triggered landslide dam blocks a river valley called?
Correct Answer: a) Landslide-dammed lake (Quake lake)
Explanation:
Attabad Lake in Hunza, Pakistan (2010) and Tangjiashan Lake in Sichuan, China (2008) are famous examples of landslide-dammed quake lakes.
92. What dangerous hazard arises when a natural landslide dam created by an earthquake suddenly fails and bursts?
Correct Answer: a) Outburst flood (Flash flood)
Explanation:
The catastrophic breaching of a landslide dam releases huge volumes of impounded water downstream as an outburst flood.
93. Which type of fault is created primarily by crustal tension where the hanging wall drops down relative to the footwall?
Correct Answer: a) Normal fault
Explanation:
Normal faults occur in divergent or extensional tectonic settings where crustal pulling pulls rock blocks downward.
94. Which type of fault is formed by compressional tectonic forces where the hanging wall moves up relative to the footwall?
Correct Answer: a) Reverse fault (Thrust fault if dip < 45°)
Explanation:
Compressional stresses push the hanging wall upward over the footwall in reverse and thrust faults.
95. A fault where rock blocks on either side slide horizontally past each other is classified as a:
Correct Answer: a) Strike-slip fault
Explanation:
Strike-slip faults (like the San Andreas and Chaman faults) accommodate lateral horizontal crustal movement.
96. What is the ratio of seismic shear-wave velocity (Vs30) in the upper 30 meters of soil used for in modern building codes?
Correct Answer: a) Site classification and ground motion amplification estimation
Explanation:
Vs30 is the primary parameter used globally to classify soil stiffness and evaluate site-specific seismic amplification factors.
97. Which automated early warning system sends alerts seconds before destructive S-waves arrive based on initial P-wave detection?
Correct Answer: a) Earthquake Early Warning (EEW) System (e.g., ShakeAlert)
Explanation:
EEW systems detect rapid P-waves near the epicenter and transmit electronic warnings to distant cities before the slower, destructive S-waves arrive.
98. Which satellite remote-sensing technique compares radar images before and after an earthquake to map millimeter-scale ground deformation?
Correct Answer: a) InSAR (Interferometric Synthetic Aperture Radar)
Explanation:
InSAR uses phase differences in satellite radar signals to create high-precision ground surface displacement interferograms.
99. The Rann of Kutch earthquake of 1819 in Sindh/Gujarat famously created an 80-km-long natural dam/scarp locally known as:
Correct Answer: a) Allah Bund (Dam of God)
Explanation:
The 1819 earthquake created a major 3 to 6-meter-high tectonic ridge called 'Allah Bund' across the Indus River delta.
100. The 1950 Assam-Tibet earthquake (magnitude 8.6) is the largest known earthquake caused by:
Correct Answer: a) Continental-continental plate collision (Himalayas)
Explanation:
The 1950 earthquake at the eastern Himalayan syntaxis is the largest recorded non-subduction continental collision event.
101. Which agency in Pakistan is officially responsible for seismic monitoring and earthquake data dissemination?
Correct Answer: a) Pakistan Meteorological Department (PMD / National Seismic Monitoring Centre)
Explanation:
The National Seismic Monitoring Centre of the PMD monitors and reports seismic and tsunami activity across Pakistan.
102. What is the primary factor determining whether an undersea earthquake will generate a dangerous tsunami?
Correct Answer: a) Significant vertical displacement of the seafloor (shallow dip-slip faulting)
Explanation:
Tsunamis require sudden vertical displacement of the ocean water column, which occurs during dip-slip thrust fault ruptures.
103. Which major subduction zone in the Pacific Northwest of the United States has a history of magnitude 9.0 earthquakes (last striking in January 1700)?
Correct Answer: a) Cascadia Subduction Zone
Explanation:
The Cascadia subduction zone off the coast of Washington and Oregon ruptured in a giant magnitude ~9.0 earthquake on January 26, 1700, sending an 'orphan tsunami' to Japan.
104. How did Japanese historical records help determine the exact date and hour of the 1700 Cascadia earthquake in North America?
Correct Answer: a) By recording the precise arrival of an 'orphan tsunami' that had no local shaking in Japan
Explanation:
Japanese port records documented an unexpected tsunami on January 27, 1700, enabling scientists to calculate the exact timing of the trans-Pacific Cascadia megaquake.
105. What is the term for a standing wave or rhythmic oscillation in an enclosed body of water (such as a lake or bay) triggered by seismic waves?
Correct Answer: a) Seiche
Explanation:
A seiche is a resonant sloshing wave in a lake, reservoir, or swimming pool caused by passing long-period seismic waves from distant earthquakes.
106. The 1964 Niigata earthquake in Japan became internationally famous among geotechnical engineers for providing classic evidence of:
Correct Answer: a) Massive building collapse due to widespread soil liquefaction
Explanation:
Apartment buildings in Niigata tipped over virtually intact like falling dominoes due to the loss of bearing capacity from liquefaction.
107. In earthquake seismology, what is 'attenuation'?
Correct Answer: a) The decrease in amplitude and energy of seismic waves as they travel away from the source
Explanation:
Attenuation is the gradual loss of seismic wave energy caused by geometric spreading and friction absorption (anelastic attenuation) in rocks.
108. Which of the following materials propagates seismic P-waves with the highest velocity?
Correct Answer: a) Dense, solid peridotite rock in the upper mantle
Explanation:
Seismic wave velocity increases with density and elastic modulus, reaching over 8 km/s in deep mantle peridotite.
109. What is the approximate speed of seismic P-waves through ordinary continental granitic crust?
Correct Answer: a) 5 to 6 km/s
Explanation:
P-waves travel at approximately 5.5 to 6.0 km/second through standard continental crustal granite.
110. What is the approximate speed of seismic S-waves through continental crust?
Correct Answer: a) 3 to 3.5 km/s
Explanation:
S-waves travel at roughly 60% of the speed of P-waves, averaging 3.0 to 3.5 km/second in upper continental crust.
111. How many separate seismograph recording stations are mathematically required at a minimum to locate the epicenter of an earthquake using triangulation?
Correct Answer: a) 3
Explanation:
Triangulation requires distance circles from at least three different seismograph stations to intersect at a unique epicentral point.
112. The time difference between the arrival of P-waves and S-waves ($S - P$ time) at a seismic station is directly proportional to:
Correct Answer: a) The distance from the station to the earthquake hypocenter
Explanation:
Because P-waves travel faster than S-waves, the gap between their arrival times increases with increasing distance from the source.
113. Which seismic wave motion consists of transverse horizontal shear displacement perpendicular to the direction of wave travel?
Correct Answer: a) Love wave
Explanation:
Love waves are horizontally polarized surface shear waves named after British mathematician A. E. H. Love.
114. Which seismic surface wave produces a retrograde elliptical particle motion resembling ocean water waves?
Correct Answer: a) Rayleigh wave
Explanation:
Rayleigh waves cause both vertical and longitudinal motion, producing a retrograde rolling elliptical motion along the surface.
115. What is the primary reason why brick masonry buildings without steel reinforcement perform poorly during earthquakes?
Correct Answer: a) Masonry has high compressive strength but very low tensile and shear strength
Explanation:
Unreinforced masonry easily cracks and crumbles under the lateral shear and tensile bending forces induced by earthquake vibrations.
116. Which construction technique involves adding diagonal steel members to structural frames to resist lateral seismic forces?
Correct Answer: a) Cross-bracing
Explanation:
Cross-bracing forms rigid triangular trusses within building bays, efficiently transmitting lateral earthquake forces to the foundations.
117. The 1990 Manjil-Rudbar earthquake (magnitude 7.4) caused over 40,000 casualties in which country's northern provinces?
Correct Answer: a) Iran
Explanation:
The Manjil-Rudbar earthquake struck Gilan and Zanjan provinces in northern Iran on June 21, 1990.
118. The 1988 Spitak earthquake (magnitude 6.8) devastated northern Armenia, then part of the Soviet Union, largely due to:
Correct Answer: a) Substandard precast-concrete panel construction and poor masonry mortar
Explanation:
Flawed design in Soviet-era prefabricated frame and stone apartment blocks led to catastrophic structural collapse in Spitak and Leninakan.
119. Which 1970 earthquake in Peru triggered a massive glacial ice and rock avalanche from Mount Huascarán, burying the city of Yungay?
Correct Answer: a) 1970 Ancash earthquake
Explanation:
The magnitude 7.9 Ancash offshore earthquake triggered a debris avalanche that buried Yungay in minutes, killing over 20,000 people.
120. What is the primary reason why earthquakes along the Mid-Atlantic Ridge generally cause little direct damage to human populations?
Correct Answer: a) They occur under the deep ocean far from populated coastlines along divergent plate boundaries
Explanation:
Mid-ocean ridge spreading centers generate numerous moderate earthquakes, but their vast distance from land prevents structural damage.
121. Which large volcanic island in the North Atlantic sits directly astride the Mid-Atlantic Ridge and experiences frequent seismic rifting?
Correct Answer: a) Iceland
Explanation:
Iceland is located on the divergent boundary between the North American and Eurasian tectonic plates, experiencing recurrent volcanism and rifting earthquakes.
122. What was the magnitude of the catastrophic earthquake that struck the Japanese port city of Kobe on January 17, 1995?
Correct Answer: a) 6.9
Explanation:
The Great Hanshin earthquake registered a magnitude of 6.9 (Mw) and resulted in more than $100 billion in damage.
123. Which historic city in Uzbekistan was virtually leveled by a shallow magnitude 5.1 earthquake on April 26, 1966, leading to a complete Soviet reconstruction?
Correct Answer: a) Tashkent
Explanation:
The 1966 Tashkent earthquake struck directly beneath the city center at a depth of only 3 to 8 km, leaving 300,000 people homeless.
124. What is the term for a temporary decrease in background seismicity observed in a fault zone prior to some major earthquakes?
Correct Answer: a) Seismic quiescence
Explanation:
Seismic quiescence refers to an unusual period of reduced minor earthquake activity in an active zone, indicating locking and stress accumulation.
125. Can scientists currently predict the exact date, time, and location of future earthquakes with high precision?
Correct Answer: a) No, reliable deterministic short-term earthquake prediction is currently impossible
Explanation:
While seismologists can calculate long-term statistical probabilities for fault zones, precise short-term forecasting remains scientifically impossible.
126. What is the primary scientific purpose of probabilistic seismic hazard analysis (PSHA)?
Correct Answer: a) To estimate the likelihood that ground motion will exceed a certain level at a specific site within a given time period
Explanation:
PSHA generates hazard maps used in national building codes to ensure structures are engineered to withstand expected peak ground accelerations.
127. Which historic Pakistani building was famously constructed using earthquake-resistant 'dhajji dewari' timber-and-masonry framing after the 1935 Quetta disaster?
Correct Answer: a) Quetta Staff College and post-1935 residential bungalows
Explanation:
Following 1935, British engineers introduced strict building codes and timber-laced 'dhajji dewari' construction across Quetta cantonment.
128. The 1934 Nepal-Bihar earthquake (magnitude 8.0) caused major liquefaction and structural collapse in which two countries?
Correct Answer: a) Nepal and India
Explanation:
The January 15, 1934 megaquake caused vast destruction across northern Bihar (Munger and Muzaffarpur) and the Kathmandu Valley in Nepal.
129. The 2002 Denali earthquake in Alaska (magnitude 7.9) famously tested which major infrastructure project that had been specifically engineered to survive fault slip?
Correct Answer: a) Trans-Alaska Pipeline System
Explanation:
The Trans-Alaska Pipeline was built on sliding Teflon supports over the Denali Fault and survived 5.5 meters of horizontal displacement without leaking.
130. Which 1886 earthquake remains the most damaging historical seismic event recorded in the southeastern United States?
Correct Answer: a) Charleston earthquake (South Carolina)
Explanation:
The August 31, 1886 intraplate earthquake in Charleston, South Carolina, killed over 60 people and was felt across much of the eastern US.
131. What is the primary cause of volcanic earthquakes?
Correct Answer: a) Movement of magma and volcanic gases creating stress fractures in surrounding rock
Explanation:
Ascending magma and pressurized gas fracture overlying rock and generate continuous harmonic volcanic tremors.
132. Harmonic tremor (volcanic tremor) recorded on a seismograph is characterized by:
Correct Answer: a) Continuous, rhythmic low-frequency seismic vibrations associated with magma flow
Explanation:
Harmonic tremors produce steady sinusoidal waveforms reflecting subsurface resonance of magma conduit fluids.
133. The 1960 Agadir earthquake (magnitude 5.8) in Morocco was catastrophic (killing a third of the city's population) primarily because:
Correct Answer: a) The shallow epicenter was located directly beneath poorly built unreinforced masonry buildings
Explanation:
The February 29, 1960 Agadir earthquake proved that even moderate-magnitude earthquakes can be lethal if shallow and centered under weak masonry.
134. Which seismic parameter represents the maximum acceleration experienced by a building foundation during ground shaking?
Correct Answer: a) Peak Ground Acceleration (PGA)
Explanation:
PGA measures the rate of change of ground velocity, typically expressed as a fraction of standard gravity ($g$), critical for structural design.
135. What is a 'blind fault' in structural geology?
Correct Answer: a) A fault that does not rupture or show displacement on the Earth's surface
Explanation:
Blind faults terminate beneath overlying sediment layers, leaving no visible surface scarp despite generating major earthquakes.
136. The 1993 Latur (Killari) earthquake in Maharashtra, India (magnitude 6.2) was notable because it occurred in a region previously classified as:
Correct Answer: a) A stable, low-risk continental shield with almost no known historical seismicity
Explanation:
The deadly Latur earthquake occurred within the stable Precambrian Deccan Traps shield, prompting widespread revisions of India's seismic zoning map.
137. What is the phenomenon where two adjacent tectonic plates along a fault zone remain stuck together by friction while continuous stress builds up?
Correct Answer: a) Fault locking (Stick-slip behavior)
Explanation:
Stick-slip friction locks fault surfaces until accumulated shear stress overcomes frictional resistance, releasing stored elastic energy as an earthquake.
138. Continuous, smooth displacement along a fault without generating noticeable earthquakes is known as:
Correct Answer: a) Aseismic fault creep
Explanation:
Aseismic creep occurs when fault surfaces slide gradually and continuously past one another without accumulating elastic strain.
139. The 2001 Arequipa earthquake (magnitude 8.4) in southern Peru occurred along which major subduction zone?
Correct Answer: a) Peru-Chile Trench (Nazca under South America)
Explanation:
The Peru-Chile Trench is one of the world's most active subduction zones, responsible for major South American megathrust earthquakes.
140. Which seismic monitoring network established during the Cold War helped confirm the theory of plate tectonics by mapping global earthquake epicenters?
Correct Answer: a) WWSSN (World-Wide Standardized Seismograph Network)
Explanation:
Originally deployed to detect underground nuclear explosions, the WWSSN precisely mapped narrow bands of global seismicity matching tectonic plate margins.
141. What is the sudden post-earthquake rise in ground water levels or well discharge often attributed to?
Correct Answer: a) Coseismic compression of aquifers and increased rock permeability from fracturing
Explanation:
Earthquake strains squeeze pore spaces in confined aquifers and fracture rock aquitards, altering local groundwater hydrology.
142. The 1927 Jericho earthquake (magnitude 6.3) caused widespread destruction and temporarily halted the flow of which river due to hillside collapse?
Correct Answer: a) Jordan River
Explanation:
The 1927 earthquake along the Dead Sea Transform triggered clay bluffs to collapse into the Jordan River, damming its flow for over 21 hours.
143. Which 1976 earthquake in Guatemala (magnitude 7.5) ruptured 230 km of the Motagua Fault, which separates:
Correct Answer: a) The North American Plate from the Caribbean Plate
Explanation:
The Motagua Fault is a major left-lateral transform boundary separating the North American and Caribbean tectonic plates.
144. What is the primary role of a 'shake table' in civil engineering research facilities?
Correct Answer: a) To subject full-scale building models to simulated real-world earthquake ground motions
Explanation:
Hydraulic shake tables (such as Japan's E-Defense) physically test structural performance and failure modes under realistic 3D seismic accelerations.
145. Which famous Roman amphitheater sustained significant structural collapses from historical earthquakes, including the major 1349 earthquake?
Correct Answer: a) Colosseum in Rome
Explanation:
The southern outer wall of the Colosseum collapsed during the 1349 central Italy earthquake because it was built over unstable alluvial stream sediment.
146. What is the term for the process where a tectonic fault continues to experience subtle, non-violent slip for weeks or months after an earthquake?
Correct Answer: a) Afterslip (Postseismic relaxation)
Explanation:
Afterslip represents stable postseismic frictional sliding on or adjacent to the earthquake rupture plane.
147. The 2009 L'Aquila earthquake (magnitude 6.3) in Italy led to a controversial and internationally debated trial involving:
Correct Answer: a) Seismologists and government officials regarding risk communication and early warning messages
Explanation:
Italian experts were initially convicted (and later acquitted) over allegations of providing overly reassuring risk assessments before the deadly 2009 quake.
148. Which of the following is a primary non-structural earthquake hazard responsible for many residential injuries?
Correct Answer: a) Falling furniture, heavy mirrors, unanchored appliances, and shattered window glass
Explanation:
Unsecured interior contents and falling debris cause a large percentage of non-fatal injuries during moderate-to-strong shaking.
149. In flexible multi-story buildings, the ground floor designed with open parking or large retail windows without shear walls is called a:
Correct Answer: a) Soft story (Soft-story building)
Explanation:
Soft-story structures lack lateral stiffness on the ground level, making them highly vulnerable to pancake collapse during strong seismic shaking.
150. Which historic earthquake on September 8, 2023, struck the High Atlas mountain range in Morocco (magnitude 6.8), causing severe damage to traditional mud-brick mountain villages?
Correct Answer: a) Al Haouz (Marrakesh-Safi) earthquake
Explanation:
The 2023 Al Haouz earthquake struck southwest of Marrakesh, devastating remote stone and adobe settlements across the Atlas Mountains.
151. The 2024 Noto Peninsula earthquake (magnitude 7.5) on January 1, 2024, caused extensive coastal uplift and fires in which country?
Correct Answer: a) Japan
Explanation:
The New Year's Day 2024 earthquake struck Ishikawa Prefecture in Japan, uplifting coastal seafloors by up to 4 meters.
152. In April 2024, a magnitude 7.4 earthquake struck near the city of Hualien on the eastern coast of:
Correct Answer: a) Taiwan
Explanation:
The Hualien earthquake was Taiwan's strongest seismic event in 25 years, demonstrating the high efficacy of modern Taiwanese building codes.
153. What is the study of how geological site conditions modify seismic ground motions at a particular location called?
Correct Answer: a) Local site effects (Site response analysis)
Explanation:
Site effects evaluate how soft soils, topography, and sedimentary basin geometry amplify or alter the frequency of seismic waves.
154. Which of the following is considered an essential component of an emergency household earthquake kit?
Correct Answer: a) At least 3 days of bottled water (1 gallon/person/day), non-perishable food, flashlight, first aid kit, and battery radio
Explanation:
Disaster preparedness guidelines recommend a minimum 72-hour survival kit with potable water, food, first-aid, lighting, and communication devices.
155. What is the primary reason natural gas valves should be shut off immediately following strong earthquake shaking if a leak is suspected?
Correct Answer: a) To prevent post-earthquake gas explosions and major urban conflagrations
Explanation:
Ruptured domestic and municipal gas lines are the leading cause of catastrophic secondary fires following major earthquakes.
156. Which structural retrofitting measure strengthens concrete columns against shear failure during seismic cycles?
Correct Answer: a) Steel or carbon-fiber-reinforced polymer (CFRP) jacketing
Explanation:
Wrapping concrete columns in steel jackets or CFRP composites provides confinement, preventing brittle shear explosion and rebar buckling.
157. What is the term for an earthquake occurring at sea that causes no ground surface rupture on land but triggers a disproportionately large tsunami?
Correct Answer: a) Tsunami earthquake
Explanation:
First identified by Hiroo Kanamori, 'tsunami earthquakes' feature unusually slow fault rupture velocities that generate little high-frequency shaking but displace vast ocean volumes.
158. The 1896 Sanriku earthquake in Japan was a classic 'tsunami earthquake' because:
Correct Answer: a) The shaking felt on shore was mild, yet it generated a catastrophic 38-meter tsunami that killed 22,000 people
Explanation:
Residents did not evacuate because the ground motion felt gentle, leading to immense casualties when the enormous tsunami hit 35 minutes later.
159. Which fault in Pakistan runs along the base of the Margalla Hills near Islamabad?
Correct Answer: a) Main Boundary Thrust (MBT) / Margalla Fault
Explanation:
The Main Boundary Thrust is a major regional fault line separating the Lesser Himalayas from the sub-Himalayan Siwaliks near Islamabad.
160. In the context of earthquake risk reduction, what does 'retrofitting' mean?
Correct Answer: a) Modifying and strengthening existing older structures to make them more resistant to seismic shaking
Explanation:
Seismic retrofitting upgrades the structural capacity of vulnerable existing buildings using braces, shear walls, or isolators.
161. Which international organization coordinates the Global Earthquake Model (GEM) to standardize global seismic hazard and risk assessment?
Correct Answer: a) GEM Foundation
Explanation:
The Global Earthquake Model Foundation is a public-private partnership that develops open-source tools and datasets for earthquake hazard modeling.
162. What is the ultimate primary source of internal heat and energy driving plate tectonics and mantle convection on Earth?
Correct Answer: a) Radiogenic decay of radioactive isotopes (Uranium, Thorium, Potassium) and primordial heat from planetary accretion
Explanation:
Earth's internal heat engine is powered by radioactive decay and residual heat left over from the planet's formation 4.5 billion years ago.
