Plate tectonics provides the unifying kinematic framework explaining seismicity, volcanism, and mountain building through the interaction of rigid lithospheric plates over the asthenosphere. First conceptualized through Alfred Wegener's Continental Drift hypothesis (1912) and formalized through seafloor spreading observations, lithospheric boundaries are classified into divergent, convergent, and transform margins. Earthquakes occur when accumulated elastic strain along faults is abruptly released; the underground point of rupture is the hypocentre (focus), directly below the epicentre on Earth's surface. Energy propagates as seismic waves: primary (P) waves are longitudinal body waves that pass through solids and liquids, secondary (S) waves are transverse shear waves that cannot penetrate liquid outer cores, and surface waves (Love and Rayleigh waves) cause structural damage. Volcanism occurs predominantly along convergent subduction zones, divergent mid-ocean ridges, and intra-plate mantle plumes (hotspots). The Circum-Pacific Belt, known as the Pacific Ring of Fire, concentrates over 75% of active terrestrial volcanoes and 90% of global earthquakes, characterized by explosive composite stratovolcanoes and deep oceanic trenches.
High-yield conceptual summaries for competitive exams and rapid revision.
Plate tectonics unifies lithospheric dynamics along divergent (constructive), convergent (destructive), and transform (conservative) plate boundaries.
Seismic energy originates at the focus (hypocentre), located vertically beneath the surface epicentre where seismic shaking is recorded first.
Body waves comprise P-waves (compressional, fastest, travel through solids/liquids) and S-waves (shear, slower, pass only through solids).
S-wave shadow zones (beyond 103° from epicentre) provided geophysicists empirical proof of Earth's liquid outer core.
The Pacific Ring of Fire accounts for roughly 90% of global earthquakes and 75% of active volcanoes along oceanic trench subduction zones.
Showing 25 Curated Questions182 Total in Bank
1ID: GK-DMGT-00064
hardEarthquake Seismic Zones, BIS Codes & Tsunamis
The deadly 1993 Latur (Killari) earthquake in Maharashtra was significant in Indian seismology because it revealed high seismic vulnerability in which geologic setting?
Verified Explanation
The 30 September 1993 Killari (Latur) earthquake (Mw 6.2) occurred within the peninsular shield, which was historically categorized as a seismically stable continental region (Zone I). This event led to the re-evaluation of peninsular seismic hazard and the elimination of Zone I in Indian codes.
2ID: GK-DMGT-00119
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
In October 2005, a devastating earthquake of magnitude Mw 7.6 struck near Muzaffarabad and caused severe casualties in Jammu & Kashmir. Along which geological fault structure did this rupture occur?
Verified Explanation
The 2005 Kashmir earthquake (Mw 7.6) was caused by a major rupture along the Balakot-Bagh Fault in the sub-Himalayan northwest syntaxial bend. It caused massive landslides, building collapses, and killed over 80,000 people across the region.
3ID: GK-DMGT-00122
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
Which premier engineering institute in India developed and deployed the early regional Earthquake Early Warning (EEW) system in Uttarakhand using real-time seismic sensor telemetry?
Verified Explanation
The Department of Earthquake Engineering at IIT Roorkee, funded by the Uttarakhand State Disaster Management Authority (USDMA), designed and operationalized the Uttarakhand Earthquake Early Warning System (UEEWS) with sensor networks providing critical seconds of advance alert based on P-wave detection.
4ID: GK-DMGT-00124
hardEarthquake Seismic Zones, BIS Codes & Tsunamis
In August 1950, which colossal earthquake with a magnitude of Mw 8.6 struck the Assam-Tibet border region, causing massive river damming and altering the course of the Brahmaputra River?
Verified Explanation
The 1950 Assam-Tibet earthquake (Mw 8.6) is the largest recorded instrumented intra-continental collision earthquake in the Himalayas. It generated massive rockslides that dammed the Subansiri and Dihang rivers; their subsequent breaches unleashed catastrophic secondary floods across Upper Assam.
5ID: GK-DMGT-00129
hardEarthquake Seismic Zones, BIS Codes & Tsunamis
Why did the 1897 Great Shillong Plateau Earthquake (Mw ~8.1) become a landmark event in global seismology studied by R.D. Oldham?
Verified Explanation
Richard Dixon Oldham's seminal 1899 memoir on the 1897 Assam (Shillong) earthquake analyzed seismograms from worldwide stations, establishing the first empirical proof that earthquake vibrations propagate as three distinct wave types: primary (P), secondary (S), and surface waves.
6ID: GK-DMGT-00296
easyEarthquake Seismic Zones, BIS Codes & Tsunamis
Which mobile application was developed by the National Centre for Seismology (NCS) to provide instant real-time earthquake epicentre and magnitude alerts to citizens?
Verified Explanation
The 'BhooKamp' mobile application was launched by the National Centre for Seismology (NCS), Ministry of Earth Sciences. It disseminates real-time earthquake parameters (origin time, epicentre, depth, magnitude) to citizens and disaster managers across India.
7ID: GK-DMGT-00300
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
The devastating 1993 Killari earthquake in Maharashtra (Magnitude 6.2) was classified as what type of unusual seismic event occurring within a stable intraplate region?
Verified Explanation
The September 30, 1993 Killari (Latur) earthquake (Mw 6.2) was a classic Stable Continental Region (SCR) intraplate earthquake. Occurring within the stable Peninsular Indian shield (previously considered seismically quiescent), it prompted a comprehensive revision of India's seismic zonation map.
8ID: GK-DMGT-00304
hardEarthquake Seismic Zones, BIS Codes & Tsunamis
Which Indian seismic zone encompassed the epicentre of the January 26, 2001 earthquake (Mw 7.7) that struck the Kachchh region of Gujarat?
Verified Explanation
The epicentre of the 2001 Bhuj earthquake (Mw 7.7 near Chobari, Bhachau taluka) lies squarely in Seismic Zone V, the highest hazard zone. The Kachchh rift basin is an active intraplate fault system characterized by major faults such as the Kutch Mainland Fault (KMF) and Katrol Hill Fault.
9ID: GK-DMGT-00305
hardEarthquake Seismic Zones, BIS Codes & Tsunamis
Which BIS standard establishes guidelines for earthquake-resistant design and construction of masonry and earthen buildings in India?
Verified Explanation
IS 4326: 2013 is the Bureau of Indian Standards code for 'Earthquake Resistant Design and Construction of Buildings'. It provides engineering detailing for masonry structures, timber construction, plinth bands, lintel bands, roof bands, and vertical reinforcement at corners and jambs.
10ID: GK-DMGT-00295
easyEarthquake Seismic Zones, BIS Codes & Tsunamis
What soil mechanics phenomenon occurs during earthquake shaking when saturated, loosely packed granular soil temporarily loses its shear strength and behaves like a liquid?
Verified Explanation
Soil liquefaction occurs when saturated loose cohesionless sandy soils experience cyclic seismic shaking, leading to an increase in pore water pressure and sudden loss of effective shear strength. This causes heavy structural settlement, foundation tilting, and sand boils during major earthquakes.
11ID: GK-DMGT-00055
easyEarthquake Seismic Zones, BIS Codes & Tsunamis
Which scale measures the intensity of an earthquake based on observable ground damage, structural collapse, and human perception rather than total energy released?
Verified Explanation
While the Richter and Moment Magnitude scales measure the intrinsic energy released by an earthquake, the Modified Mercalli Intensity (MMI) scale (ranging from I to XII in Roman numerals) measures the physical effects, destruction, and intensity observed at specific surface locations.
12ID: GK-DMGT-00058
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
What is the specific Zone Factor (Z) value assigned to Seismic Zone IV in BIS IS 1893:2016 for calculating earthquake design forces?
Verified Explanation
As per IS 1893:2016, the Zone Factors (Z) representing Maximum Considered Earthquake (MCE) peak ground acceleration are: Zone II = 0.10, Zone III = 0.16, Zone IV = 0.24, and Zone V = 0.36.
13ID: GK-DMGT-00060
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
The catastrophic December 2004 Indian Ocean Tsunami was triggered by a 9.1–9.3 magnitude megathrust earthquake along which tectonic subduction zone?
Verified Explanation
The 26 December 2004 earthquake occurred along the Sunda Trench (Sumatra-Andaman subduction zone) where the Indo-Australian Plate subducts beneath the Burma Microplate. The sudden vertical seafloor displacement of several meters triggered tsunami waves across the entire Indian Ocean.
14ID: GK-DMGT-00061
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
The devastating 2001 Bhuj earthquake in Gujarat (Mw 7.7), which occurred on Republic Day, was situated in which seismic hazard zone?
Verified Explanation
The Kutch region of Gujarat, including Bhuj, is located in Seismic Zone V (the highest seismic risk zone in India). The 26 January 2001 earthquake was caused by intraplate thrust faulting along the Kutch Mainland Fault and South Wagad Fault system.
15ID: GK-DMGT-00070
hardEarthquake Seismic Zones, BIS Codes & Tsunamis
During the 2004 Indian Ocean megathrust earthquake, Indira Point on Great Nicobar Island underwent what major geophysical alteration?
Verified Explanation
The 2004 Sumatra-Andaman earthquake caused massive co-seismic crustal deformation across the Andaman and Nicobar archipelago. Great Nicobar Island experienced substantial co-seismic subsidence (over 4.25 meters), causing the Indira Point lighthouse base to be permanently submerged in seawater.
16ID: GK-DMGT-00116
easyEarthquake Seismic Zones, BIS Codes & Tsunamis
Which Indian government organization under the Ministry of Earth Sciences is the nodal agency for monitoring earthquake activity and maintaining the National Seismological Network across India?
Verified Explanation
The National Centre for Seismology (NCS), an attached office of the Ministry of Earth Sciences (MoES), operates the National Seismological Network comprising over 150 digital telemetry stations to detect, locate, and disseminate earthquake parameters in real time.
17ID: GK-DMGT-00117
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
Which Bureau of Indian Standards (BIS) code specifically lays down guidelines for 'Improving Earthquake Resistance of Low Strength Masonry Buildings' across rural and semi-urban India?
Verified Explanation
IS 13828:1993 specifies earthquake-resistant construction features for low-strength masonry buildings (such as unburnt mud blocks, random rubble stone masonry, and unreinforced clay brick walls), including horizontal seismic bands at plinth, lintel, and roof levels.
18ID: GK-DMGT-00175
easyEarthquake Seismic Zones, BIS Codes & Tsunamis
The severe December 1967 earthquake of magnitude 6.3 in Maharashtra is historically recognized in global seismology as a classic textbook example of which phenomenon?
Verified Explanation
The 1967 Koyna earthquake (M 6.3) occurred following the impoundment of the Shivajisagar reservoir behind the Koyna Dam in Maharashtra. It is considered one of the largest and most well-documented cases of Reservoir-Induced Seismicity (RIS) in stable intraplate peninsular India.
19ID: GK-DMGT-00179
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
Which great earthquake in June 1819 caused an ~80-km long, 6-meter high natural earthen wall/scarp known as the 'Allah Bund' to form across the Rann of Kutch?
Verified Explanation
The June 16, 1819 Rann of Kutch earthquake (Mw ~7.8) created a massive 80-km long, 6-meter high fault scarp that dammed the Puran River. The local inhabitants named this sudden tectonic uplift 'Allah Bund' (Mound of God).
20ID: GK-DMGT-00183
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
Within how many minutes of an undersea tsunamigenic earthquake occurring in the Indian Ocean can the Indian Tsunami Early Warning Centre (ITEWC) at INCOIS Hyderabad generate its initial advisory bulletin?
Verified Explanation
The Indian Tsunami Early Warning Centre (ITEWC) at INCOIS is engineered with high-speed automated seismic analysis software (Earthworm / SeisComP3) and pre-computed tsunami propagation scenario databases that allow dissemination of warning advisories within 10 minutes of an earthquake.
21ID: GK-DMGT-00184
hardEarthquake Seismic Zones, BIS Codes & Tsunamis
In geotechnical earthquake engineering, what safety ratio between Cyclic Resistance Ratio (CRR) and Cyclic Stress Ratio (CSR) determines the Factor of Safety (FS) against soil liquefaction?
Verified Explanation
The Factor of Safety against liquefaction is evaluated as FS=CSRCRR, where CRR represents the capacity of the soil to resist liquefaction and CSR represents the earthquake-induced cyclic shear stress. An FS<1.0 indicates that liquefaction is triggered.
22ID: GK-DMGT-00185
hardEarthquake Seismic Zones, BIS Codes & Tsunamis
What geologic term describes a subterranean thrust fault that does not rupture or show visible displacement on the surface of the Earth, making it invisible to surface geological mapping until an earthquake occurs?
Verified Explanation
A 'Blind Thrust Fault' is a thrust fault that terminates within subsurface rock strata before reaching the surface. Because it produces no surface fault scarp, it is difficult to detect before an earthquake occurs, as seen in catastrophic events like Northridge (1994) or Killari (1993).
23ID: GK-DMGT-00231
easyEarthquake Seismic Zones, BIS Codes & Tsunamis
Which Indian Standard code published by the Bureau of Indian Standards covers the earthquake resistant design and construction of masonry buildings?
Verified Explanation
IS 4326 ('Earthquake Resistant Design and Construction of Buildings - Code of Practice') specifically regulates the seismic safety, masonry bond detailing, and continuous horizontal reinforced bands (plinth, lintel, and roof bands) in masonry structures.
24ID: GK-DMGT-00236
easyEarthquake Seismic Zones, BIS Codes & Tsunamis
Which great earthquake in Indian history (M ~8.0+) led geologist Richard Dixon Oldham to identify and distinguish P-waves, S-waves, and surface waves in seismograms?
Verified Explanation
The 12 June 1897 Great Assam Earthquake was meticulously surveyed by Richard Dixon Oldham of the Geological Survey of India. His seminal 1899 memoir on this earthquake provided the world's first clear identification of the three main seismic wave types (P, S, and surface waves).
25ID: GK-DMGT-00243
mediumEarthquake Seismic Zones, BIS Codes & Tsunamis
Which massive 1950 earthquake (M 8.6), one of the largest continental collision events in recorded history, caused massive landslides that dammed the Subansiri and Dihang rivers in Northeast India?
Verified Explanation
The 15 August 1950 Assam-Tibet earthquake (Mw 8.6) occurred in the eastern Himalayan syntaxis. It generated immense landslides that dammed the Subansiri, Dibang, and Dihang rivers. Days later, the Subansiri landslide dam burst, causing catastrophic secondary flooding.