1. Which seismic wave phase reflects directly off the outer surface of Earth's liquid outer core before returning to the surface?
Correct Answer: a) PcP wave
Explanation:
The 'c' in PcP signifies a reflection at the core-mantle boundary (Gutenberg discontinuity) back up to the surface.
2. A compressional seismic wave that refracts into the outer core and re-emerges into the mantle is designated as a:
Correct Answer: a) PKP wave
Explanation:
The letter 'K' (from German 'Kern', core) denotes a wave traveling through Earth's liquid outer core.
3. Which seismic wave phase originates as a shear wave, travels through the outer core as a compressional wave, and exits as a shear wave?
Correct Answer: a) SKS wave
Explanation:
An SKS wave converts from S to P upon entering the liquid outer core (where shear waves cannot travel) and converts back to S upon re-entering the mantle.
4. The 2001 Kunlun earthquake in Tibet set a world record for the longest strike-slip surface rupture mapped by satellite radar. What was its rupture length?
Correct Answer: a) Over 400 kilometers
Explanation:
On November 14, 2001, an 7.8 Mw earthquake ruptured over 426 km of the left-lateral Kunlun Fault across the northern Tibetan Plateau.
5. The 1906 San Francisco earthquake ruptured roughly how many kilometers of the Northern San Andreas Fault?
Correct Answer: a) 477 kilometers
Explanation:
The April 18, 1906 San Francisco earthquake ruptured approximately 477 km (nearly 300 miles) of the northern San Andreas Fault zone.
6. The 1857 Fort Tejon earthquake ruptured roughly how many kilometers of the southern San Andreas Fault?
Correct Answer: a) 350 kilometers
Explanation:
The January 9, 1857 earthquake (~7.9 Mw) ruptured roughly 350 km of the southern San Andreas Fault between Parkfield and Wrightwood.
7. What is the primary factor limiting the maximum potential earthquake magnitude along a specific fault zone?
Correct Answer: a) Total fault rupture surface area and rock rigidity
Explanation:
Seismic moment ($M_0 = \mu A D$) depends directly on fault rigidity ($μ$), fault rupture area ($A$), and average displacement ($D$).
8. The 1999 İzmit earthquake in Turkey ruptured along which major plate boundary fault system?
Correct Answer: a) North Anatolian Fault Zone
Explanation:
The August 17, 1999 magnitude 7.6 quake ruptured a 120-km section of the right-lateral strike-slip North Anatolian Fault.
9. Which historic 1923 earthquake devastated the metropolitan region of Tokyo and Yokohama in Japan?
Correct Answer: a) Great Kantō Earthquake
Explanation:
Striking on September 1, 1923, the Great Kantō earthquake (7.9 Mw) destroyed Tokyo and Yokohama, causing immense firestorms.
10. The 1960 Valdivia Earthquake in Chile is historically notable as the:
Correct Answer: a) Most powerful earthquake instrumentally recorded, registering magnitude 9.5
Explanation:
Occurring on May 22, 1960, the Valdivia earthquake registered a record 9.5 on the Moment Magnitude Scale.
11. The 1556 Shaanxi earthquake in Ming Dynasty China holds which historical distinction?
Correct Answer: a) Deadliest earthquake in recorded human history (~830,000 casualties)
Explanation:
The January 23, 1556 Shaanxi earthquake killed an estimated 830,000 people, largely due to the collapse of artificial cave dwellings (yaodongs).
12. Which tectonic subduction zone was responsible for the catastrophic 2004 Indian Ocean earthquake and tsunami?
Correct Answer: a) Sunda Megathrust
Explanation:
The 2004 megathrust quake occurred along the Sunda Trench off northern Sumatra, where the Indo-Australian plate subducts beneath the Sunda plate.
13. The 2011 Great East Japan Earthquake (Tōhoku) reached what magnitude on the Moment Magnitude Scale?
Correct Answer: a) 9.0 – 9.1
Explanation:
The March 11, 2011 Tōhoku megathrust earthquake off Sendai measured 9.0–9.1 Mw, triggering powerful tsunami waves across East Japan.
14. Which Caribbean country experienced a devastating magnitude 7.0 earthquake on January 12, 2010, centered near Léogâne?
Correct Answer: a) Haiti
Explanation:
The 2010 Haiti earthquake caused massive destruction in Port-au-Prince and surrounding towns, claiming over 200,000 lives.
15. The 1755 Lisbon earthquake occurred on which significant religious holiday in Europe?
Correct Answer: a) All Saints' Day (November 1)
Explanation:
Striking on All Saints' Day morning, church candles lit throughout Lisbon ignited firestorms following the structural collapse.
16. The 1964 Great Alaska Earthquake occurred on which holiday, earning it the name 'Good Friday Earthquake'?
Correct Answer: a) Good Friday (March 27)
Explanation:
The 9.2 Mw megathrust earthquake struck Prince William Sound, Alaska, on Good Friday, March 27, 1964.
17. The October 8, 2005 Kashmir earthquake (magnitude 7.6) had its epicenter near which capital city of Azad Jammu and Kashmir?
Correct Answer: a) Muzaffarabad
Explanation:
The 2005 Kashmir earthquake epicenter was located directly northeast of Muzaffarabad, causing widespread loss of life.
18. The 1976 Tangshan earthquake, which resulted in an official death toll exceeding 240,000, occurred in which country?
Correct Answer: a) China
Explanation:
On July 28, 1976, an 7.5 Mw earthquake struck the industrial city of Tangshan in Hebei Province, China.
19. The 1995 Great Hanshin earthquake, which killed over 6,000 people, is more commonly named after which major Japanese port city?
Correct Answer: a) Kobe
Explanation:
Striking on January 17, 1995, the Kobe earthquake (6.9 Mw) severely damaged infrastructure across the Hanshin metropolitan region.
20. The 2015 Gorkha earthquake (magnitude 7.8) severely impacted which Himalayan nation?
Correct Answer: a) Nepal
Explanation:
On April 25, 2015, a 7.8 Mw thrust earthquake struck central Nepal, causing widespread damage in Kathmandu.
21. In February 2023, two powerful earthquakes (magnitudes 7.8 and 7.5) caused catastrophic destruction across which two nations?
Correct Answer: a) Turkey and Syria
Explanation:
On February 6, 2023, twin strike-slip ruptures along the East Anatolian Fault Zone devastated southern Turkey and northern Syria.
22. The famous 1811–1812 intraplate earthquakes occurred along which seismic zone in the central United States?
Correct Answer: a) New Madrid Seismic Zone
Explanation:
A series of intense earthquakes centered near New Madrid, Missouri, temporarily reversed the flow direction of the Mississippi River.
23. The 1692 earthquake in Jamaica famously submerged two-thirds of which pirate port city into the sea?
Correct Answer: a) Port Royal
Explanation:
On June 7, 1692, earthquake shaking and soil liquefaction caused large portions of Port Royal to sink into Kingston Harbour.
24. The Modified Mercalli Intensity (MMI) Scale measures an earthquake based on which observational criteria?
Correct Answer: a) Perceived shaking intensity, structural damage, and localized surface effects
Explanation:
MMI rates local shaking effects on humans, objects, and buildings using Roman numerals ranging from I to XII.
25. The 1985 Mexico City earthquake caused severe structural damage 350 km from its epicenter due to ground wave amplification in:
Correct Answer: a) Soft clay sediments of the ancient Lake Texcoco lakebed
Explanation:
Deep soft clay deposits under Mexico City trapped and amplified incoming low-frequency seismic waves, causing severe structural resonance.
26. The 1988 Spitak earthquake (magnitude 6.8) occurred in which former Soviet Republic?
Correct Answer: a) Armenia
Explanation:
On December 7, 1988, a devastating earthquake struck northern Armenia (then Armenian SSR), destroying the town of Spitak.
27. The 1908 Messina earthquake and tsunami destroyed towns bordering which body of water between Sicily and mainland Italy?
Correct Answer: a) Strait of Messina
Explanation:
On December 28, 1908, an 7.1 Mw earthquake devastated Messina in Sicily and Reggio Calabria on the Italian mainland.
28. The 1999 Chi-Chi earthquake, also called the '921 Earthquake', struck central region of which territory?
Correct Answer: a) Taiwan
Explanation:
Striking on September 21, 1999 (921 local date code), a 7.7 Mw thrust earthquake caused major destruction across central Taiwan.
29. The 1970 Ancash earthquake in Peru triggered a massive rock-ice avalanche off which mountain peak, burying the city of Yungay?
Correct Answer: a) Mount Huascarán
Explanation:
Shaking dislodged a massive glacier-rock debris sheet from Mt. Huascarán, which swept down the valley and buried Yungay.
30. The 2001 Gujarat earthquake in India, which occurred on India's Republic Day (January 26), had its epicenter in which district?
Correct Answer: a) Kutch (Kachchh)
Explanation:
The 7.7 magnitude intraplate earthquake was centered in the Kutch district of Gujarat near Bhuj.
31. What soil failure phenomenon occurs when water-saturated sand loses shear strength and behaves like a liquid during strong ground shaking?
Correct Answer: a) Soil liquefaction
Explanation:
Liquefaction occurs when cyclic shaking increases pore water pressure in loose, saturated soils, turning them into a fluid slurry.
32. The 2010 Maule earthquake (magnitude 8.8), one of the largest recorded in South American history, occurred in which nation?
Correct Answer: a) Chile
Explanation:
On February 27, 2010, an 8.8 Mw megathrust earthquake ruptured off central Chile, triggering tsunamis across the Pacific.
33. The 1989 Loma Prieta earthquake interrupted Game 3 of the Major League Baseball World Series in which region?
Correct Answer: a) San Francisco Bay Area
Explanation:
The October 17, 1989 earthquake hit Northern California during live coverage of the World Series between San Francisco and Oakland.
34. The 2003 Bam earthquake severely damaged the 2,000-year-old mud-brick Arg-e Bam citadel in which nation?
Correct Answer: a) Iran
Explanation:
On December 26, 2003, a 6.6 Mw earthquake destroyed the historic adobe city of Bam in southeastern Iran.
35. Which 1971 Southern California earthquake prompted major updates to hospital construction safety laws and state building codes?
Correct Answer: a) San Fernando (Sylmar) Earthquake
Explanation:
The February 9, 1971 Sylmar quake caused collapse at Olive View Hospital, leading to the California Hospital Seismic Safety Act.
36. The 2011 Christchurch earthquake, which caused severe destruction in the city center, was an aftershock sequence of which earlier 2010 quake?
Correct Answer: a) Darfield (Canterbury) Earthquake
Explanation:
The February 22, 2011 Christchurch quake (6.2 Mw) occurred as an aftershock of the September 4, 2010 Darfield event (7.1 Mw).
37. Which seismic wave is a compressional body wave that travels fastest through both solid rock and liquid media?
Correct Answer: a) P-wave (Primary)
Explanation:
Primary (P) waves are compressional body waves that travel fastest through materials and propagate in solids, liquids, and gases.
38. Which type of body wave moves rock particles side-to-side perpendicular to the direction of wave travel and cannot pass through liquids?
Correct Answer: a) S-wave (Secondary)
Explanation:
Secondary (S) waves are shear waves that oscillate perpendicular to propagation and cannot transmit through liquid media.
39. The 1935 Quetta earthquake, which killed over 30,000 people, occurred in which modern-day country?
Correct Answer: a) Pakistan
Explanation:
On May 31, 1935, a magnitude 7.7 earthquake destroyed Quetta, capital of British India's Balochistan province (now Pakistan).
40. The 1994 Northridge earthquake in Southern California occurred on what type of unmapped fault structure?
Correct Answer: a) Blind thrust fault
Explanation:
The Northridge earthquake occurred on a blind thrust fault that does not breach or break the ground surface directly.
41. What is the underground point within the Earth where an earthquake rupture originates?
Correct Answer: a) Hypocenter (or Focus)
Explanation:
The hypocenter (or focus) is the point of initial fault slip deep underground; the epicenter is the point directly above it on the surface.
42. The 1700 Cascadia earthquake was dated precisely to January 26, 1700 using written tsunami arrival logs from which country?
Correct Answer: a) Japan
Explanation:
Japanese samurai and village records recorded an 'orphan tsunami' on Jan 26, 1700, linked to the Pacific Northwest megathrust quake.
43. The 1946 Aleutian Islands earthquake generated a killer tsunami that caused vast destruction in Hilo in which US state?
Correct Answer: a) Hawaii
Explanation:
The April 1, 1946 tsunami hit Hilo, Hawaii, leading to the creation of the Pacific Tsunami Warning Center.
44. Which historic Japanese earthquake in 1855 struck the feudal capital city of Edo (modern-day Tokyo)?
Correct Answer: a) Ansei Edo Earthquake
Explanation:
The November 11, 1855 Ansei Edo earthquake destroyed large parts of Edo, killing over 7,000 residents.
45. The 1975 Haicheng earthquake in China holds what distinction in seismological history?
Correct Answer: a) First successfully predicted earthquake that led to timely city evacuation
Explanation:
Chinese scientists issued an evacuation order hours before the 7.3 Mw quake based on foreshocks and unusual groundwater/animal signs.
46. The 1964 Niigata earthquake in Japan became a classic engineering case study due to widespread structural damage from:
Correct Answer: a) Soil liquefaction
Explanation:
Extreme soil liquefaction in Niigata caused intact reinforced concrete apartment buildings to tip over into liquefied soil.
47. The 1933 Long Beach earthquake prompted California to enact which law mandating seismic safety standards for public schools?
Correct Answer: a) Field Act
Explanation:
Enacted in 1933 following school building collapses, the Field Act mandated earthquake-resistant design standards for public schools.
48. Which 1883 volcanic island explosion generated massive seismic tremors and a global ocean tsunami in the Sunda Strait?
Correct Answer: a) Krakatoa
Explanation:
The cataclysmic eruption of Krakatoa in August 1883 generated sea waves and seismic disturbances recorded around the globe.
49. The 1999 İzmit earthquake in Turkey ruptured along which specific segment of the North Anatolian Fault Zone?
Correct Answer: a) Marmara / İzmit Segment
Explanation:
The August 17, 1999 event ruptured the western extension of the North Anatolian Fault Zone near İzmit and the Gulf of İzmit.
50. The 2008 Sichuan earthquake (Wenchuan earthquake) in China occurred along which major fault zone at the margin of the Sichuan Basin?
Correct Answer: a) Longmenshan Fault
Explanation:
On May 12, 2008, a 7.9 Mw thrust earthquake ruptured the Longmenshan Fault at the western margin of the Sichuan Basin.
51. The 1857 Fort Tejon earthquake ruptured the southern portion of which famous California transform fault?
Correct Answer: a) San Andreas Fault
Explanation:
The 1857 event ruptured roughly 350 km of the southern San Andreas Fault, with horizontal displacement reaching up to 9 meters.
52. Which European capital was devastated by a combination of earthquake, fires, and tsunami on November 1, 1755?
Correct Answer: a) Lisbon
Explanation:
The Great Lisbon earthquake destroyed the Portuguese capital, profoundly shaping Enlightenment philosophy and science.
53. The time difference between P-wave and S-wave arrival times at a seismograph station is primarily used to determine:
Correct Answer: a) Distance from the station to the earthquake epicenter
Explanation:
Because P-waves travel faster than S-waves, the time lag between their arrival times grows proportionally with distance to the seismic source.
54. The 1952 Kamchatka earthquake (magnitude 9.0) generated a destructive tsunami that wiped out which Soviet town?
Correct Answer: a) Severo-Kurilsk
Explanation:
On November 4, 1952, a 9.0 Mw megathrust quake generated tsunamis that destroyed Severo-Kurilsk in the Kuril Islands.
55. The 1972 Nicaragua earthquake, which destroyed downtown Managua, prompted relief efforts by which baseball legend who died in a plane crash delivering aid?
Correct Answer: a) Roberto Clemente
Explanation:
Pittsburgh Pirates star Roberto Clemente died on December 31, 1972, when his aid plane crashed en route to relief efforts in Managua.
56. The 1905 Kangra earthquake, which killed over 20,000 people, occurred in which northern Indian state?
Correct Answer: a) Himachal Pradesh
Explanation:
On April 4, 1905, a magnitude 7.8 earthquake hit the Kangra valley region of present-day Himachal Pradesh.
57. The 1931 Hawke's Bay earthquake (Napier earthquake) stands as the deadliest natural disaster in which southern hemisphere nation?
Correct Answer: a) New Zealand
Explanation:
On February 3, 1931, a magnitude 7.8 earthquake devastated the towns of Napier and Hastings on the North Island of New Zealand.
58. On the Richter local magnitude scale, each integer increase represents a factor increase in measured ground wave amplitude of:
Correct Answer: a) 10-fold
Explanation:
The Richter scale is logarithmic; each whole number increase corresponds to a 10-fold increase in measured seismograph amplitude.
59. An earthquake of magnitude 8 releases approximately how much more total seismic energy than an earthquake of magnitude 6?
Correct Answer: a) 1,000 times more energy
Explanation:
Each integer magnitude step releases $\approx 31.6$ times more energy. A 2-unit magnitude difference corresponds to $31.6 \times 31.6 \approx 1,000$ times more energy.
60. The high seismicity across Greece and the Aegean Sea is primarily caused by the subduction of which tectonic plate?
Correct Answer: a) African Plate subducting beneath the Aegean Sea microplate
Explanation:
The African Plate converges northward, subducting beneath the Hellenic Arc in the Eastern Mediterranean.
61. The 2009 L'Aquila earthquake in central Italy led to a notable legal case involving members of which profession?
Correct Answer: a) Seismologists and risk evaluation scientific advisors
Explanation:
Italian scientists were initially convicted of manslaughter over public risk messaging prior to the L'Aquila quake (later mostly acquitted on appeal).
62. The 1976 Guatemala earthquake (magnitude 7.5) ruptured which transform fault separating the Caribbean and North American plates?
Correct Answer: a) Motagua Fault
Explanation:
The February 4, 1976 earthquake ruptured over 230 km of the Motagua left-lateral strike-slip fault across Guatemala.
63. The 1707 Hōei earthquake in Japan triggered a volcanic eruption of which iconic peak 49 days later?
Correct Answer: a) Mount Fuji
Explanation:
The 1707 megathrust quake altered magma pressure beneath Mount Fuji, triggering its last historical eruption (Hōei Eruption) in Dec 1707.
64. Which 1966 California earthquake led to the establishment of long-term fault monitoring experiments along the San Andreas Fault?
Correct Answer: a) Parkfield Earthquake
Explanation:
The 1966 Parkfield quake prompted the USGS Parkfield Experiment to study characteristic recurring earthquakes along the fault segment.
65. The 2002 Denali earthquake in Alaska (7.9 Mw) ruptured beneath which critical engineering structure without causing a breach?
Correct Answer: a) Trans-Alaska Pipeline System (TAPS)
Explanation:
Specialized earthquake sliders and flexible supports allowed 14 feet of lateral offset beneath the pipeline without tearing the steel pipe.
66. What instrument is designed specifically to measure ground acceleration changes during major earthquake shaking?
Correct Answer: a) Accelerograph
Explanation:
Accelerographs record ground acceleration over time, providing engineers with Peak Ground Acceleration (PGA) data.
67. The 1948 Ashgabat earthquake, which killed an estimated 110,000 people, destroyed the capital of which Soviet Republic?
Correct Answer: a) Turkmenistan
Explanation:
On October 6, 1948, a magnitude 7.3 earthquake destroyed Ashgabat, capital of the Turkmen SSR.
68. The 1963 Skopje earthquake destroyed over 80% of the capital of present-day North Macedonia, which was then part of:
Correct Answer: a) Yugoslavia
Explanation:
On July 26, 1963, a magnitude 6.1 earthquake destroyed Skopje, leading to an international reconstruction initiative in Yugoslavia.
69. Tectonic plate boundaries where plates slide horizontally past one another are classified as:
Correct Answer: a) Transform boundaries
Explanation:
Transform boundaries involve horizontal strike-slip motion as tectonic plates scrape horizontally past each other.
70. The 1990 Manjil-Rudbar earthquake (magnitude 7.4), which killed over 40,000 people, occurred in which country?
Correct Answer: a) Iran
Explanation:
On June 21, 1990, a major earthquake struck northern Iran in Gilan and Zanjan provinces.
71. The 2016 Kaikōura earthquake in New Zealand was scientifically notable because it:
Correct Answer: a) Ruptured at least 21 distinct fault lines in a single complex sequence
Explanation:
The 7.8 Mw Kaikōura earthquake involved a complex fault rupture cascade propagating across 21 separate onshore and offshore fault lines.
72. The 1927 Gulang earthquake (magnitude 7.6) caused extensive loess landslides in which Chinese province?
Correct Answer: a) Gansu
Explanation:
On May 22, 1927, a 7.6 magnitude quake struck Gansu Province, China, triggering massive landslides across loess hills.
73. The 1356 Basel earthquake stands as the strongest historic seismic event recorded in which region of Europe?
Correct Answer: a) Central Europe (North of the Alps)
Explanation:
On October 18, 1356, an earthquake centered near Basel, Switzerland, destroyed the city and surrounding castles.
74. The planar zone of dipping seismicity that traces a subducting oceanic slab plunging into the mantle is called the:
Correct Answer: a) Wadati-Benioff Zone
Explanation:
Named after Kiyoo Wadati and Hugo Benioff, this zone outlines hypocenters marking subducting oceanic lithosphere.
75. The 1993 Latur (Killari) earthquake in Maharashtra, India, was significant because it occurred in a region considered to be:
Correct Answer: a) A stable intraplate continental shield (Deccan Traps)
Explanation:
The 6.2 Mw Latur quake struck a region of the Deccan Craton previously considered low risk for severe earthquakes.
76. Which seismic isolation engineering technique decouples a building structure from ground shaking using elastomeric bearings?
Correct Answer: a) Base isolation
Explanation:
Base isolation places flexible bearings or pads between a building foundation and superstructure to absorb horizontal ground motion.
77. The Taipei 101 skyscraper in Taiwan contains which iconic engineering device suspended inside to absorb structural sway during quakes?
Correct Answer: a) Tuned Mass Damper (660-tonne pendulum)
Explanation:
A massive 660-tonne steel sphere suspended between the 87th and 92nd floors acts as a tuned mass damper against wind and seismic sway.
78. The 1966 Tashkent earthquake led to major Soviet urban redesign and reconstruction in the capital of which country?
Correct Answer: a) Uzbekistan
Explanation:
On April 26, 1966, a shallow 5.2 Mw earthquake destroyed central Tashkent, leading to a Soviet effort to rebuild the Uzbek capital.
79. Smaller seismic events occurring in the same fault region following a main earthquake are known as:
Correct Answer: a) Aftershocks
Explanation:
Aftershocks are lower-magnitude earthquakes occurring along or near the original rupture plane as stress readjusts.
80. The 1693 Sicily earthquake prompted extensive rebuilding across south-eastern Sicily in which architectural style?
Correct Answer: a) Sicilian Baroque
Explanation:
Reconstruction of 56 ruined towns following the 1693 Val di Noto earthquake created the distinctive Sicilian Baroque architectural tradition.
81. The 2018 Sulawesi earthquake in Indonesia caused extreme destruction in Palu city due to rapid flow-slide:
Correct Answer: a) Soil liquefaction
Explanation:
On September 28, 2018, shaking triggered massive flow liquefaction in Palu districts like Balaroa and Petobo, sliding whole neighborhoods downhill.
82. The 1920 Haiyuan earthquake, which killed over 200,000 people due to landslides, occurred in which region of China?
Correct Answer: a) Ningxia
Explanation:
On December 16, 1920, a ~7.8 magnitude earthquake hit Ningxia, triggering loess landslides that buried whole villages.
83. The 1929 Grand Banks earthquake off Newfoundland broke twelve submarine telegraph cables due to what phenomenon?
Correct Answer: a) Submarine turbidity currents (underwater sediment avalanches)
Explanation:
Earthquake shaking dislodged continental slope sediments, creating a fast-moving density current that severed seabed cables.
84. The Pacific 'Ring of Fire' accounts for approximately what percentage of the world's earthquakes?
Correct Answer: a) 90%
Explanation:
Approximately 90% of global earthquakes occur along the Pacific Ring of Fire, a belt of oceanic trenches and plate boundaries.
85. The boundary separating Earth's crust from the underlying mantle is named after which Croatian meteorologist and seismologist?
Correct Answer: a) Andrija Mohorovičić
Explanation:
Andrija Mohorovičić identified the seismic velocity jump in 1909 that marks the crust-mantle boundary (the Moho).
86. The 1977 Vrancea earthquake (magnitude 7.5) caused structural collapses in Bucharest, the capital city of:
Correct Answer: a) Romania
Explanation:
On March 4, 1977, an intermediate-depth earthquake in the Vrancea zone collapsed dozens of high-rise structures in Bucharest.
87. The 1945 Balochistan earthquake (magnitude 8.1) generated a destructive tsunami in the Arabian Sea along the coast of modern-day:
Correct Answer: a) Pakistan
Explanation:
On November 27, 1945, a subduction earthquake in the Makran Trench generated a tsunami that struck Pasni and Ormara in Pakistan.
88. The 2021 Haiti earthquake (magnitude 7.2) occurred along which microplate boundary fault system?
Correct Answer: a) Enriquillo-Plantain Garden Fault Zone
Explanation:
The August 14, 2021 earthquake struck the Tiburon Peninsula along the Enriquillo-Plantain Garden fault zone west of Port-au-Prince.
89. The existence of an S-wave shadow zone beyond 104 degrees from an earthquake epicenter demonstrates that Earth's outer core is:
Correct Answer: a) Liquid
Explanation:
Because shear S-waves cannot transmit through liquids, their complete blockage beyond ~104° proves the outer core is fluid.
90. The 1906 Valparaíso earthquake in Chile struck in the same calendar year as which major US earthquake disaster?
Correct Answer: a) 1906 San Francisco Earthquake
Explanation:
Both the San Francisco quake (April 1906) and the Valparaíso quake (August 1906) occurred along Pacific margin fault systems in 1906.
91. The 2017 Puebla earthquake in Mexico (magnitude 7.1) occurred on the exact 32nd anniversary of which historic earthquake?
Correct Answer: a) 1985 Mexico City Earthquake
Explanation:
On September 19, 2017, central Mexico was struck by a 7.1 Mw earthquake on the anniversary of the 1985 disaster.
92. A 'tsunami earthquake' is defined in seismology as an earthquake that:
Correct Answer: a) Generates a disproportionately large tsunami relative to its moderate ground-shaking intensity on land
Explanation:
Tsunami earthquakes rupture slowly along shallow subduction zones, causing weak land shaking while displacing huge sea water volumes.
93. The 1950 Assam–Tibet earthquake (magnitude 8.6) holds the record as the largest instrumentally recorded earthquake caused by:
Correct Answer: a) Continental collision (Indo-Eurasian plate convergence)
Explanation:
On August 15, 1950, a magnitude 8.6 quake occurred in the Eastern Himalayas, making it the largest recorded continental convergence event.
94. The JMA Seismic Intensity Scale (Shindo) used in Japan measures ground shaking on a scale ranging from:
Correct Answer: a) 0 to 7
Explanation:
The Japan Meteorological Agency measures localized ground shaking intensity from 0 (unfelt) to 7 (severe structural failure).
95. The 1940 Imperial Valley earthquake in California yielded the first high-quality strong-motion recording from which instrument?
Correct Answer: a) El Centro Accelerograph
Explanation:
The May 18, 1940 El Centro record provided the first clear accelerogram of near-fault ground shaking for structural engineers.
96. The 1960 Agadir earthquake, which destroyed a third of the city's population, occurred in which North African nation?
Correct Answer: a) Morocco
Explanation:
On February 29, 1960, a magnitude 5.7 shallow earthquake devastated Agadir, Morocco, killing over 12,000 people.
97. What structural fault movement occurs under tensional tectonic forces when the hanging wall drops down relative to the footwall?
Correct Answer: a) Normal fault
Explanation:
Normal faults occur in extensional tectonic environments where the hanging wall block moves downward relative to the footwall.
98. Reverse or thrust faults occur under which principal stress state in the Earth's crust?
Correct Answer: a) Compressional stress
Explanation:
Compression forces push crustal blocks together, driving the hanging wall upward relative to the footwall along reverse or low-angle thrust faults.
99. The 1959 Hebgen Lake earthquake in Montana triggered a massive landslide that dammed the Madison River, forming which new body of water?
Correct Answer: a) Quake Lake (Earthquake Lake)
Explanation:
The August 17, 1959 quake dislodged 37 million cubic yards of rock, damming the Madison River to create Earthquake Lake.
100. Sir Richard Dixon Oldham identified the three primary seismic wave groups (P, S, and Surface waves) while analyzing records of which 1897 earthquake?
Correct Answer: a) 1897 Assam Earthquake
Explanation:
Oldham's 1899 analysis of the June 12, 1897 Assam earthquake proved that seismic disturbances travel as distinct P, S, and surface wave arrivals.
101. The Alpine Fault is a major active transform fault line running through the South Island of which country?
Correct Answer: a) New Zealand
Explanation:
The Alpine Fault forms the transform boundary between the Pacific and Indo-Australian plates through New Zealand's South Island.
102. The 1855 Wairarapa earthquake uplifted land around Wellington harbor in New Zealand by up to how many meters?
Correct Answer: a) 2 meters (6 feet)
Explanation:
The 1855 Wairarapa quake (~8.2 Mw) raised the Wellington shoreline by up to 2 meters, exposing new coastal flats.
103. Transverse surface waves that vibrate ground side-to-side in a horizontal plane without vertical displacement are called:
Correct Answer: a) Love waves
Explanation:
Love waves are surface waves that move ground horizontally perpendicular to the direction of wave travel.
104. Surface waves that cause ground particles to move in a vertical rolling elliptical orbit are classified as:
Correct Answer: a) Rayleigh waves
Explanation:
Rayleigh waves roll along the ground surface in elliptical motion, causing both vertical and horizontal displacement.
105. Earthquakes that occur deep within continental plate interiors far from active plate boundaries are termed:
Correct Answer: a) Intraplate earthquakes
Explanation:
Intraplate earthquakes occur in the interior of tectonic plates (e.g. New Madrid, Charleston) rather than along plate margins.
106. The Juan de Fuca Plate subducts beneath the North American Plate along which major Pacific Northwest subduction zone?
Correct Answer: a) Cascadia Subduction Zone
Explanation:
The Cascadia Subduction Zone stretches from Northern California to Vancouver Island, where the Juan de Fuca plate subducts eastward.
107. Elastic Rebound Theory, formulated by Harry Fielding Reid after the 1906 San Francisco earthquake, explains that earthquakes are caused by:
Correct Answer: a) The sudden release of elastic strain energy accumulated in deformed rock along a fault
Explanation:
Reid showed that tectonic forces slowly deform rocks elastically until stress exceeds fault strength, snapping rocks back to release seismic energy.
108. The 1746 Lima–Callao earthquake destroyed the capital of Peru and generated a tsunami that wiped out which adjacent port city?
Correct Answer: a) Callao
Explanation:
On October 28, 1746, an ~8.6 magnitude subduction quake struck Lima; the resulting tsunami inundated Callao.
109. The main cause of destructive tsunamis during subduction earthquakes is the:
Correct Answer: a) Rapid vertical displacement of the seafloor displacing the overlying water column
Explanation:
When the overriding subduction plate springs upward during fault slip, it vertically displaces thousands of cubic kilometers of ocean water.
110. The 1886 Charleston earthquake was the largest historical earthquake recorded in which US region?
Correct Answer: a) Southeastern United States
Explanation:
On August 31, 1886, an estimated 6.9–7.3 magnitude intraplate quake hit Charleston, South Carolina.
111. The 1989 Cypress Street Viaduct double-deck highway collapse occurred in which California city during the Loma Prieta quake?
Correct Answer: a) Oakland
Explanation:
The upper deck of the Interstate 880 Cypress Viaduct in Oakland collapsed onto the lower deck, causing 42 fatalities.
112. The 1509 Constantinople earthquake in the Ottoman Empire was historically referred to by citizens as:
Correct Answer: a) The Lesser Judgment Day
Explanation:
The September 1509 earthquake destroyed walls, towers, and mosques in Istanbul, earning the historical title 'Küçük Kıyamet'.
113. The 1958 Lituya Bay earthquake in Alaska triggered the highest recorded tsunami run-up in history (524 meters / 1,720 feet) due to:
Correct Answer: a) An earthquake-triggered massive rockslide into a confined fjord
Explanation:
A 7.8 Mw quake dislodged 40 million cubic yards of rock into Gilbert Inlet, creating a giant wave splash up the opposing mountain slope.
114. An instrument that uses an invar rod or wire stretched across a fault line to measure slow non-seismic fault slip is called a:
Correct Answer: a) Creepmeter
Explanation:
Creepmeters continuously measure localized horizontal surface fault displacement along creeping fault zones.
115. The 1989 Newcastle earthquake (magnitude 5.6) was a rare deadly event in which stable intraplate continent?
Correct Answer: a) Australia
Explanation:
On December 28, 1989, a magnitude 5.6 intraplate quake struck Newcastle, New South Wales, Australia, killing 13 people.
116. The 1994 Bolivia deep earthquake occurred at a mantle depth of roughly:
Correct Answer: a) 640 kilometers
Explanation:
On June 9, 1994, an 8.2 Mw earthquake occurred within the subducted Nazca slab 647 km beneath Bolivia.
117. The Wasatch Fault Zone is an active normal fault network running along the western base of the Wasatch Range in which US state?
Correct Answer: a) Utah
Explanation:
The Wasatch Fault runs adjacent to Salt Lake City and the Wasatch Front urban corridor in Utah.
118. The Gutenberg-Richter relation $\log_{10} N = a - bM$ expresses the statistical relationship between earthquake magnitude ($M$) and:
Correct Answer: a) The total number of earthquakes (N) occurring of magnitude M or greater
Explanation:
The Gutenberg-Richter law quantifies earthquake frequency-magnitude distributions across regions over time.
119. Omori's Law in seismology models which temporal characteristic of earthquake sequences?
Correct Answer: a) The rate of decay of aftershocks over time following a main shock
Explanation:
Omori's Law states that aftershock frequency decreases roughly hyperbolically with elapsed time after the mainshock.
120. Earthquake activity resulting directly from human industrial operations like deep wastewater disposal or reservoir filling is known as:
Correct Answer: a) Induced seismicity
Explanation:
Induced seismicity refers to earthquakes triggered by human activities that modify fluid pore pressures or subsurface stresses.
121. The surge in earthquake frequency in Oklahoma between 2009 and 2016 was primarily caused by:
Correct Answer: a) Deep underground disposal of oil and gas production wastewater
Explanation:
High-volume fluid injection into deep disposal formations increased pore fluid pressures along ancient basement faults in Oklahoma.
122. The 1967 Koynanagar earthquake (magnitude 6.6) in India is a famous global example of seismic activity induced by:
Correct Answer: a) Reservoir impoundment behind the Koyna Dam
Explanation:
Filling the Koyna Reservoir increased pore pressure and crustal loading, inducing a magnitude 6.6 earthquake in 1967.
123. The Basin and Range Province of western North America is characterized structurally by which dominant faulting style?
Correct Answer: a) Extensional normal faulting
Explanation:
Tectonic stretching across the Basin and Range creates alternating tilted fault blocks bounded by active normal faults.
124. The 1918 Puerto Rico earthquake generated a destructive tsunami in which marine passage?
Correct Answer: a) Mona Passage
Explanation:
On October 11, 1918, a 7.1 Mw earthquake in the Mona Canyon generated tsunami waves that struck western Puerto Rico.
125. In earthquake structural engineering, a 'soft story' building failure refers to:
Correct Answer: a) Structural collapse of a ground floor containing wide openings (like garages or storefronts) lacking lateral shear rigidity
Explanation:
Soft-story structures have ground levels with minimal shear walls that collapse laterally when subjected to horizontal shaking.
126. Following the 1755 Lisbon earthquake, the Marquis of Pombal introduced wooden anti-seismic building frames known as:
Correct Answer: a) Gaiola pombalina (Pombaline cage)
Explanation:
Engineers developed symmetrical three-dimensional timber cages embedded within masonry walls to resist seismic forces during Lisbon's reconstruction.
127. The 1906 San Francisco fire burned uncontrollably for three days primarily because:
Correct Answer: a) Earthquake ground movement severed municipal water main pipelines
Explanation:
Ruptured supply pipelines coming into the city left firefighters without water pressure to combat spread of urban fires.
128. Deep-water ocean buoys deployed globally to detect tsunami wave passage in real time belong to the network known as:
Correct Answer: a) DART (Deep-ocean Assessment and Reporting of Tsunamis)
Explanation:
DART stations use seafloor pressure sensors linked to surface buoys to measure millimeter sea-level variations caused by passing tsunamis.
129. Standing wave oscillations generated in enclosed or semi-enclosed bodies of water like lakes or reservoirs by distant earthquake waves are termed:
Correct Answer: a) Seiches
Explanation:
Seiches are standing waves set in motion inside lakes or bays when low-frequency seismic waves pass through the basin.
130. The 1980 Mount St. Helens eruption in Washington state was immediately triggered by a magnitude 5.1 earthquake that caused a massive:
Correct Answer: a) Sector collapse landslide of the mountain's north flank
Explanation:
Shaking dislodged the unstable bulged north face of Mt. St. Helens, unleashing a giant landslide that uncapped the lateral blast.
131. Continuous, low-frequency rhythmic seismic vibrations recorded near active volcanoes caused by underground magma movement are called:
Correct Answer: a) Volcanic tremors (harmonic tremors)
Explanation:
Harmonic tremors are sustained seismic signals generated by the flow of magma or volcanic fluids through conduit networks.
132. The 2006 Pingtung earthquakes off southern Taiwan severed submarine fiber-optic telecommunication cables by triggering:
Correct Answer: a) High-velocity underwater turbidity currents
Explanation:
Ground shaking dislodged submarine canyon sediments, creating high-speed density currents that broke multiple seabed cables.
133. What primary geological phenomenon creates the volcanism and associated seismicity of the Hawaiian Islands?
Correct Answer: a) Mantle plume (Hotspot)
Explanation:
The Hawaiian island chain is formed as the Pacific Plate moves over a stationary mantle plume or hotspot.
134. Peak Ground Acceleration (PGA) is an engineering parameter measured as a fraction or percentage of:
Correct Answer: a) Acceleration due to gravity (g)
Explanation:
PGA measures peak ground acceleration experienced during shaking relative to Earth's standard gravitational acceleration ($1g \approx 9.8\text{ m/s}^2$).
135. The 2008 Iwate-Miyagi Nairiku earthquake in Japan recorded an extraordinary peak vertical ground acceleration reaching:
Correct Answer: a) 4.3g
Explanation:
A station at West Ichinoseki recorded a peak vertical ground acceleration vector of $4.3g$ ($4,278\text{ cm/s}^2$), launching loose surface objects upward.
136. Earthquake Early Warning (EEW) systems provide advance alert seconds before destructive shaking arrives by detecting fast-moving:
Correct Answer: a) P-waves
Explanation:
EEW networks detect the initial, faster P-wave and transmit electronic alerts at light speed before slower, damaging S-waves and surface waves arrive.
137. The USGS-operated real-time earthquake early warning system deployed across California, Oregon, and Washington is named:
Correct Answer: a) ShakeAlert
Explanation:
ShakeAlert is the official automated early warning system covering the US West Coast.
138. Mexico City's SASMEX early warning system can issue public alerts up to 60 seconds in advance because the major earthquake epicenters lie far away along the:
Correct Answer: a) Middle America Trench
Explanation:
Subduction quakes occur over 300 km away on the Pacific coast, allowing electronic warnings to outrun seismic waves traveling toward Mexico City.
139. The term 'blind zone' in Earthquake Early Warning system operations refers to the area:
Correct Answer: a) Directly surrounding the epicenter where seismic waves arrive before the alert can be processed and broadcast
Explanation:
Near the hypocenter, the time gap between P- and S-wave arrivals is too short for electronic networks to issue alerts prior to shaking.
140. Drowned western red cedar 'ghost forests' along the Washington and Oregon coasts were created by co-seismic subsidence during which Cascadia earthquake?
Correct Answer: a) 1700 Cascadia Earthquake
Explanation:
Coastal land dropped abruptly during the January 1700 subduction quake, submerging coastal cedar forests in saltwater.
141. Static stress change calculations following an earthquake rely on which physical metric to estimate potential hazard changes on nearby faults?
Correct Answer: a) Coulomb Failure Stress Change (\Delta\text{CFF})
Explanation:
Seismologists calculate $\Delta\text{CFF}$ to determine whether stress changes pushed adjacent faults closer to or further from failure.
