Practical Seismic Surface Wave Methods

by Dr. Julian Ivanov

*Please note: This course is not available for in-house training.

Duration: One-day

Intended Audience: Entry and Intermediate levels

Prerequisites (Knowledge/Experience/Education required): The course is designed to be followed by anyone with a broad geoscience background: no specific detailed foreknowledge is required, although a familiarity with geophysical terminology (e.g., frequency, Fourier Transform) will be useful.

Summary:
The short course will include: a theoretical overview, raw data samples, data processing examples, and exercises to help evaluate and experience the MASW analysis method. Various practical topics related to MASW data acquisition and analysis will be covered, including, optimum field spread-size determination, dispersion-curve imaging, inversion of Rayleigh-wave dispersion curves, and construction of 2D Vs images. The course will examine case studies, such as, mapping bedrock, mapping fault zones, studying levees, 3D characteristics of seismic properties, earthquake hazard assessment, etc., as a means to help evaluate and appreciate the range of applications currently employing the MASW method. Use of 2D Vs estimates for enhancing static corrections for both Vs and Vp reflection seismic data processing will be discussed. The goal of the short course is to build an understanding of and skill set with the method sufficient that participants can confidently incorporate the MASW method in their work. Attendees will be provided software with a temporary license to use during the short course and options for practice with once back at their office.

Learner Outcomes:

  • Recognize surface wave energy on raw seismic data.
  • Estimate overall dispersion-curve phase velocity, approximate depth of investigation, and 1D shear-wave velocity (Vs) trend from raw data.
  • Construct a dispersion-curve from filtered raw seismic data.
  • Calculate a 1D Vs depth section using approximate inversion method.
  • Compare the estimated approximate 1D Vs results with those obtained using a deterministic inversion algorithm.
  • Appraise raw seismic data for the possibility of the application of muting technique for the purpose of enhancing dispersion curve imaging.
  • Choose optimum spread-size and source-offset field parameters for optimum dispersion curve visualization and defend the choice.
  • Differentiate fundamental-mode from higher modes and defend/argue about it.
  • Select inversion parameters.
  • Select an inversion algorithm approach (i.e., approximate, deterministic, statical) depending on the project requirements.
  • Develop a plan for estimation of optimal field-survey parameters for MASW analysis given required goals and depth of investigation.

Instructor Biography:
Dr. Julian Ivanov