Quiz: Qab 3013 - Seismic Wave & Imaging

40 Questions | Total Attempts: 44

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Quiz: Qab 3013 - Seismic Wave & Imaging

Instructions:1. Time given is 40 minutes (considering you have 40 questions to answer). 2. There are 40 questions: 20 MCQ and 20 True/False. 3. Please be honest, and not to google for answer. 4. Good luck, and all the best.


Questions and Answers
  • 1. 
    Why do we need seismic migration / seismic imaging?
    • A. 

      Enhancing velocity information of subsurface.

    • B. 

      Correct apparent reflector position that was obtained in pre-processing data.

    • C. 

      Removing the effect of noise and multiples from the seismic data.

    • D. 

      As a connector to Geology-Geophysics sequence (G&G Link).

  • 2. 
    The following are the information can be obtained from a seismic trace EXCEPT:
    • A. 

      Wavenumber.

    • B. 

      Bulk Modulus.

    • C. 

      Frequency.

    • D. 

      Velocity.

  • 3. 
    What is the TRUE concept of a wave?
    • A. 

      Wave move in plane and only able to travel in a straight line.

    • B. 

      Wave can either be reflected and or refracted only.

    • C. 

      Wave can be attenuated by any factor.

    • D. 

      The wave movement is a process of heat transfer.

  • 4. 
    Which statements is TRUE about Fourier Transform?
    • A. 

      An algorithm used to convert time domain data to Fourier domain.

    • B. 

      An algorithm function that turns frequency data into sinusoidal waves.

    • C. 

      A transform used in engineering for complex number arithmetic.

    • D. 

      Mathematical tool that shows us how to deconstruct the waveform into its sinusoidal components.

  • 5. 
    When a S-wave strikes an interface, the energy will be partitioned into the following wave EXCEPT:
    • A. 

      Reflected Shear wave.

    • B. 

      Transmitted Shear wave.

    • C. 

      Reflected Surface wave.

    • D. 

      Reflected Pressure wave.

  • 6. 
    Which of the following sequence indicate the correct velocity sequence (from fastest toslowest) ?
    • A. 

      Scholte wave > S-wave > Rayleigh wave > Love wave.

    • B. 

      P-wave > S-wave > Love wave > Rayleigh wave.

    • C. 

      P-wave > Love wave > Rayleigh wave > S-wave.

    • D. 

      P-wave > Stoneley wave > S-wave > Scholte wave.

  • 7. 
    The figure shows a seismic activity in an earthquake occurs recently. Identify the seismic events indicate in X
    • A. 

      Surface Waves.

    • B. 

      P-Waves.

    • C. 

      S-Waves.

    • D. 

      Converted Waves.

  • 8. 
    The two figures show two similar shot record but the right figure appears differently due to some external factors affecting seismic wave propagation. Which is the most probable factor influence the shot record in the right figure?
    • A. 

      Absorption.

    • B. 

      Geometrical Spreading.

    • C. 

      Multiples.

    • D. 

      Scattering.

  • 9. 
    Current data acquisition, processing and imaging put high emphasise on acquiring and imaging the seismic data using low frequency seismic signal. Why do we need low frequency signal?
    • A. 

      Better inversion result using Full Waveform Inversion technique.

    • B. 

      Improve seismic resolution of thin beds.

    • C. 

      Enhance seismic image during seismic migration.

    • D. 

      Reduce Fresnel zone for better 3D migration.

  • 10. 
    From acoustic wave equation derivation, several other equations can be derived including:i.   Helmholtz equation.ii.  Dispersion equation.iii. Rayleigh integral equation.iv.  Elastic wave equation.
    • A. 

      I, ii and iv.

    • B. 

      I, ii and iii.

    • C. 

      I, iii and iv. 

    • D. 

      Ii, iii and iv.

  • 11. 
    A diffraction response for a homogeneous single velocity media is:
    • A. 

      Non-Hyperbolic.

    • B. 

      Amplitude decays exponentially from apex.

    • C. 

      Phase is asymmetrical.

    • D. 

      Frequency attenuated with depth.

  • 12. 
    The following is principle of Huygens’ Principle EXCEPT:
    • A. 

      Every point is the source of a secondary wave front.

    • B. 

      These secondary wave front can propagate upward or downward.

    • C. 

      Amplitude & phase in secondary wave front is same as the primary wave front.

    • D. 

      The superposition of these secondary wave front will create a new wave front.

  • 13. 
    A dispersive media is characterized by:
    • A. 

      Velocity changing linearly with depth.

    • B. 

      Interval velocity changing with time.

    • C. 

      Velocity function of frequency.

    • D. 

      Phase change according to velocity.

  • 14. 
    The characteristics of Stoneley wave is given by:
    • A. 

      A type of body wave.

    • B. 

      Found at solid-solid interface.

    • C. 

      Can be derived from Rayleigh wave.

    • D. 

      Have a speed close to P-wave velocity.

  • 15. 
    Diffraction hyperbola for a constant velocity is:
    • A. 

      Same irrespective of depth.

    • B. 

      Narrower as depth increase.

    • C. 

      Broader as depth increase.

    • D. 

      Shorter as depth increase.

  • 16. 
    What is the correct effect to seismic image, if the seismic data acquisition is conducted with a higher fold number?
    • A. 

      Better resolution

    • B. 

      Poor imaging

    • C. 

      Poor resolution

    • D. 

      Better signal to noise ratio

  • 17. 
    Seismic wave propagation is usually affected by absorption phenomenon. What is the consequences of absorption ?
    • A. 

      Delay in phase of seismic signal.

    • B. 

      Wave propagate scattered away from receiver.

    • C. 

      Increase in signal frequency.

    • D. 

      Constant seismic signal amplitude.

  • 18. 
    Choose the correct statement about Evanesecent Wave:
    • A. 

      The wave field imaginary solution cannot be remove through kz solution.

    • B. 

      The evanescent wave energy decay linearly from the source

    • C. 

      The wave field cannot be reconstructed for measurement at far-field.

    • D. 

      The far field wave energy is consider relevant.

  • 19. 
    From an acoustic wave equation, how we can derive a ray tracing signal?
    • A. 

      By taking a Fourier transform from time domain to frequency domain.

    • B. 

      By incorporating imaginary solution to wave equation.

    • C. 

      By taking into account the elastic component of the seismic wave.

    • D. 

      By taking a high frequency approximation to the wave equation.

  • 20. 
    Which one of the following theory is not involved in wave field propagation in a homogenous media?
    • A. 

      Principle of Superposition

    • B. 

      Rayleigh Integral.

    • C. 

      Gauss Theorem

    • D. 

      Green's Function

  • 21. 
    Rayleigh wave can penetrate deep into earth.
    • A. 

      True

    • B. 

      False

  • 22. 
    Fresnel zone is a function of angle of incidence. 
    • A. 

      True

    • B. 

      False

  • 23. 
    Reflection coefficient as a function of angle for a plane wave impinging on a plane reflector obeys Newton’s Law. 
    • A. 

      True

    • B. 

      False

  • 24. 
    Surface wave attenuate in linear with depth.
    • A. 

      True

    • B. 

      False

  • 25. 
    Ultimate vibroseis signal is in zero-phase after correlation with reference signal.
    • A. 

      True

    • B. 

      False

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