Seismology and seismics

Description

This course covers the basic uses of seismic waves for imaging Earth structure. Starting from the properties of elastic waves (wave-speeds and polarization), the course explores Snell’s law and reflection and refraction coefficients with applications to both refraction seismic prospecting and reflection seismic prospecting. The course also gives an overview of standard reflection seismics processing steps (deconvolution, normal move-out correction, migration).

Compétences requises

Continuum mechanics

Compétences visées

By the end of this course the student should be able to:

·        Use the polarization of seismic waves to predict how they will be recorded on 3-component seismometers.

·        Use the ray parameter to determine the path of a seismic wave through a layered medium.

·        Predict the first-arrival travel-time curve for a layered medium.

·        Determine the seismic velocity and thicknesses of layers in a layered medium from a first-arrival travel-time curve.

·        Predict the amplitudes and polarizations of a zero-offset reflection profile for a layered medium.

·        Interpret zero-offset reflection profiles in terms of Earth structure.

·        Predict the normal move-out for common mid-point gathers of a reflection seismic survey.

·        Understand the methods used to remove the influence of the seismic pulse on reflection seismic data.

·        Understand the methods used to remove diffraction artefacts from reflection seismic data.

Syllabus

Seismic waves; Polarization; Snell’s law; Refraction; Reflection; Ray-parameter; Travel-time curves; Delay times; Reflection coefficients; Normal move-out; Migration. 

Bibliographie

·        Peter M. Shearer. Introduction to seismology. Cambridge University Press

·        Seth Stein & Michael Wysession. An introduction to Seismology, Earthquakes, and Earth structure. Blackwell Publishing

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