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Weak localization of seismic waves
E Larose1, L Margerin, B A Van Tiggelen
1Laboratoire de Géophysique Interne et Tectonophysique, Observatoire de Grenoble, Université Joseph Fourier and CNRS, BP 53, 38041 Grenoble, France.
Physical Review Letters
|August 25, 2004
Summary
Researchers observed weak seismic wave localization in nature, noting a doubling of energy near the source. This phenomenon, occurring over tens of meters, is linked to the scattering mean-free time and internal earth heterogeneity.
Area of Science:
- Geophysics
- Wave physics
- Seismology
Background:
- Seismic wave propagation is influenced by Earth's heterogeneous structure.
- Understanding wave scattering is crucial for seismic imaging and hazard assessment.
Purpose of the Study:
- To report the first observation of weak seismic wave localization in a natural environment.
- To characterize the spatial extent and temporal dynamics of this phenomenon.
Main Methods:
- Field observation of seismic wave propagation in a natural setting.
- Analysis of seismic energy distribution around a source.
- Correlation of observed phenomena with scattering mean-free time.
Main Results:
- Observed weak localization of seismic waves, characterized by a doubling of seismic energy.
- Localized energy was confined to a region approximately one seismic wavelength wide (tens of meters).
- The onset time of localization was found to be related to the scattering mean-free time.
Conclusions:
- Weak seismic wave localization is a real phenomenon in natural environments.
- The scattering mean-free time is a key parameter in quantifying seismic heterogeneity and wave localization.
- This observation provides new insights into seismic wave propagation and scattering processes.
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