Earthquake Engineering - Vol 2 | 19. Elements of Seismology by Abraham | Learn Smarter
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19. Elements of Seismology

19. Elements of Seismology

Seismology is essential to understanding earthquakes and ground motion, guiding engineers in designing earthquake-resistant structures. This chapter focuses on the causes of earthquakes, the nature of seismic waves, measurement scales, and the characteristics of ground motion critical for civil engineering applications. It also highlights earthquake risk assessment, recent seismic events, and future trends in earthquake prediction.

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  1. 19
    Elements Of Seismology

    The section explores the fundamentals of seismology, including the causes of...

  2. 19.1
    Causes Of Earthquakes

    This section covers the main causes of earthquakes, including tectonic...

  3. 19.1.1
    Tectonic Movements

    Tectonic movements are the primary cause of most earthquakes, resulting from...

  4. 19.1.2
    Volcanic Activity

    This section discusses earthquakes caused by volcanic activity, highlighting...

  5. 19.1.3
    Induced Seismicity

    Induced seismicity refers to earthquakes that are a result of human...

  6. 19.1.4
    Collapse Earthquakes

    Collapse earthquakes occur due to underground cave-ins or mine collapses,...

  7. 19.2
    Elastic Rebound Theory

    The Elastic Rebound Theory explains how energy accumulated in rocks along a...

  8. 19.3
    Seismic Waves

    This section discusses seismic waves, their types, and their properties,...

  9. 19.3.1

    Body waves are seismic waves that travel through the Earth's interior,...

  10. 19.3.1.a
    Primary (P) Waves

    Primary (P) waves are the fastest type of seismic body waves and can travel...

  11. 19.3.1.b
    Secondary (S) Waves

    Secondary (S) waves are a type of seismic wave that travel slower than...

  12. 19.3.2
    Surface Waves

    Surface waves are seismic waves that travel along the Earth's surface and...

  13. 19.3.2.a

    Love waves are a type of surface seismic wave characterized by horizontal...

  14. 19.3.2.b
    Rayleigh Waves

    Rayleigh waves are a type of surface seismic wave that causes both vertical...

  15. 19.4
    Seismographs And Seismometers

    Seismographs and seismometers are crucial instruments used to detect and...

  16. 19.4.1

    The section elaborates on the essential components of seismographs and...

  17. 19.4.2
    Strong-Motion Seismographs

    Strong-motion seismographs are specialized instruments designed to record...

  18. 19.5
    Earthquake Magnitude And Intensity

    This section covers the concepts of earthquake magnitude and intensity,...

  19. 19.5.1

    This section explains how earthquake magnitude quantifies the energy...

  20. 19.5.2

    This section discusses the concept of earthquake intensity as a qualitative...

  21. 19.6
    Earthquake Zoning And Seismic Hazard Maps

    This section discusses seismic zoning and the creation of seismic hazard...

  22. 19.6.1
    Seismic Zoning

    Seismic zoning is the categorization of geographic regions based on their...

  23. 19.6.2
    Parameters Considered

    This section outlines the primary parameters influencing seismic zoning and...

  24. 19.6.3
    Indian Seismic Zoning Map (Is:1893)

    The Indian Seismic Zoning Map (IS:1893) provides design acceleration values...

  25. 19.7
    Ground Motion Characteristics

    This section discusses the characteristics of ground motion during...

  26. 19.7.1
    Peak Ground Acceleration (Pga)

    Peak Ground Acceleration (PGA) measures the maximum acceleration experienced...

  27. 19.7.2

    This section discusses the significance of the duration of ground motion...

  28. 19.7.3
    Frequency Content

    Frequency content refers to the range of frequencies present in ground...

  29. 19.7.4
    Response Spectrum

    The Response Spectrum is a critical tool for understanding how structures...

  30. 19.8
    Earthquake Recording Networks

    Earthquake recording networks are crucial for monitoring seismic activity...

  31. 19.8.1
    Global Seismographic Network (Gsn)

    The Global Seismographic Network (GSN) is a collaborative network designed...

  32. 19.8.2
    Indian National Seismological Network (Insn)

    The Indian National Seismological Network (INSN), operated by the India...

  33. 19.9
    Plate Tectonics And Indian Context

    This section explores the critical role of plate tectonics in understanding...

  34. 19.9.1
    Plate Boundaries Near India

    This section discusses the interaction between the Indo-Australian Plate and...

  35. 19.9.2
    Indian Earthquake-Prone Regions

    This section describes the regions in India that are highly prone to...

  36. 19.10
    Faults And Focal Mechanisms

    This section discusses the different types of faults and the concept of...

  37. 19.10.1

    This section describes various types of faults in tectonic settings,...

  38. 19.10.2
    Focal Mechanism

    The focal mechanism describes the orientation of a fault and the direction...

  39. 19.11
    Site Effects And Local Soil Conditions

    This section discusses how local soil conditions can amplify seismic waves...

  40. 19.11.1
    Site Amplification

    Site amplification occurs when soft soils amplify seismic waves more than...

  41. 19.11.2
    Liquefaction

    Liquefaction is a phenomenon where saturated soils lose strength and behave...

  42. 19.12
    Earthquake Early Warning Systems (Eews)

    Earthquake Early Warning Systems (EEWS) provide timely alerts of impending...

  43. 19.12.1

    The principle of Earthquake Early Warning Systems (EEWS) relies on detecting...

  44. 19.12.2

    This section discusses the practical applications of Earthquake Early...

  45. 19.13
    Engineering Applications Of Seismology

    This section covers the critical applications of seismology in engineering...

  46. 19.14
    Seismotectonics

    Seismotectonics studies the relationship between earthquakes and tectonic...

  47. 19.14.1
    Definition And Scope

    Seismotectonics is the study of the interplay between earthquakes,...

  48. 19.14.2
    Fault Mapping

    Fault mapping helps identify active faults and their history of movements,...

  49. 19.14.3
    Regional Seismotectonics In India

    This section highlights the key seismotectonic regions of India, including...

  50. 19.15
    Seismic Microzonation

    Seismic microzonation involves subdividing a region into zones with similar...

  51. 19.15.1

    The concept of seismic microzonation involves dividing a region into zones...

  52. 19.15.2
    Parameters Considered

    This section outlines the crucial parameters used in seismic microzonation,...

  53. 19.15.3

    The section discusses the practical applications of seismic microzonation in...

  54. 19.16
    Seismic Hazard Assessment

    Seismic Hazard Assessment evaluates potential ground shaking caused by...

  55. 19.16.1

    This section discusses two primary types of seismic hazard assessments:...

  56. 19.16.2

    This section focuses on the outputs of seismic hazard assessment, including...

  57. 19.17
    Earthquake Recurrence And Return Period

    This section discusses the concepts of earthquake recurrence intervals and...

  58. 19.17.1
    Recurrence Interval

    The recurrence interval is the average time between two large earthquakes on...

  59. 19.17.2
    Gutenberg-Richter Relationship

    The Gutenberg-Richter Relationship quantifies the relationship between the...

  60. 19.18
    Recent Major Earthquakes In India And Their Seismological Analysis

    This section discusses significant earthquakes in India, highlighting their...

  61. 19.18.1
    Bhuj Earthquake (2001)

    The Bhuj Earthquake in 2001, with a magnitude of 7.7, caused significant...

  62. 19.18.2
    Sikkim Earthquake (2011)

    The Sikkim Earthquake of 2011, with a magnitude of 6.9, highlighted the...

  63. 19.18.3
    Nepal-Gorkha Earthquake (2015)

    The Nepal-Gorkha earthquake of 2015, with a magnitude of 7.8, impacted...

  64. 19.19
    Future Trends In Seismology And Earthquake Prediction

    This section discusses emerging trends in seismology, focusing on advanced...

  65. 19.19.1
    Earthquake Forecasting

    Earthquake forecasting involves predicting seismic events based on...

  66. 19.19.2
    Real-Time Seismology

    Real-time seismology involves utilizing advanced technologies like GPS and...

  67. 19.19.3
    Global Collaborations

    This section discusses the importance of global partnerships in seismology...

What we have learnt

  • Seismology is the study of earthquakes and elastic wave propagation.
  • Understanding seismic waves is crucial for assessing ground motion and its effects on structures.
  • Earthquake preparedness includes recognizing the causes and predicting potential seismic hazards.

Key Concepts

-- Elastic Rebound Theory
Describes how energy is stored in rocks along fault lines and released during an earthquake.
-- Magnitude vs. Intensity
Magnitude quantifies energy released at an earthquake's source, while intensity measures effects on people and structures.
-- Seismic Zoning
Classification of regions based on seismic hazard levels to aid in engineering design and urban planning.
-- Liquefaction
A phenomenon where saturated soils lose strength during shaking, potentially leading to structural failures.
-- Response Spectrum
A plot that shows how single-degree-of-freedom systems respond to ground motion based on peak acceleration, velocity, and displacement.

Additional Learning Materials

Supplementary resources to enhance your learning experience.