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Green's functions for a volume source in an elastic half-space.
Evgenia A Zabolotskaya1, Yurii A Ilinskii, Todd A Hay
1Applied Research Laboratories, The University of Texas at Austin, Austin, Texas 78713-8029, USA.
The Journal of the Acoustical Society of America
|March 20, 2012
Summary
This study derives Green's functions for elastic waves from shallow buried sources. The findings are crucial for seismo-acoustic detection of buried objects using surface and bulk wave analysis.
Area of Science:
- Geophysics
- Acoustics
- Wave Propagation
Background:
- Elastic waves are generated by volume sources in homogeneous isotropic half-spaces.
- Shallow burial depths produce comparable surface (Rayleigh) and bulk (longitudinal, transverse) waves.
- Understanding wave generation is key for detecting buried objects.
Purpose of the Study:
- Derive Green's functions for elastic waves from shallow buried sources.
- Analyze the contributions of surface and bulk waves.
- Provide a foundation for seismo-acoustic detection applications.
Main Methods:
- Green's function derivation using Rayleigh wave eigenmode expansion.
- Green's function derivation using angular spectrum decomposition.
- Numerical analysis of the Green's function in the time domain.
Main Results:
- Two distinct approaches yield consistent Green's functions for Rayleigh waves.
- Angular spectrum method separates contributions from bulk and Rayleigh waves.
- Numerical analysis validates the Green's function for various burial depths and receiver distances.
Conclusions:
- The derived Green's functions accurately model elastic wave propagation from shallow sources.
- The methods are applicable to seismo-acoustic detection of land mines and buried objects.
- This work enhances the understanding of wave phenomena in geophysical contexts.
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