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Viscoelastic Characterization of Soft Tissue-Mimicking Gelatin Phantoms using Indentation and Magnetic Resonance Elastography
Published on: May 10, 2022
Nondiffuse elastic and anelastic passive imaging.
Francesco Mulargia1, Silvia Castellaro
1Dipartimento di Fisica, Settore di Geofisica, Universita di Bologna, Bologna 40121, Italy. francesco.mulargia@unibo.it
The Journal of the Acoustical Society of America
|March 25, 2010
Summary
Passive acoustic imaging can now undistort wave velocity and track seismic noise sources. This method measures material dissipation, offering insights into geological structures and noise origins.
Area of Science:
- Geophysics
- Acoustics
- Seismology
Background:
- Passive acoustic imaging relies on the source-receiver property between any two points.
- This property is applicable even in nondiffuse wave fields.
Purpose of the Study:
- To develop a method for undistorted passive imaging using statistical mode for wave velocity estimation.
- To determine the azimuth of instantaneous Huygens sources in the noise wavefield.
- To measure the material dissipation constant as a function of frequency.
Main Methods:
- Exploiting the source-receiver property for passive imaging.
- Utilizing the statistical mode for wave velocity estimation.
- Analyzing seismic noise in the Ravenna shore area, North-Central Italy.
Main Results:
- Achieved velocity dispersion curves consistent with independent surveys.
- Identified major firms in Ravenna port as primary seismic noise sources, with rapid source switching.
- Measured a frequency-independent dissipation quality factor (Q) of approximately 20 in the 1-30 Hz range.
Conclusions:
- Passive acoustic imaging is effective for seismic noise analysis, providing accurate velocity and dissipation measurements.
- The method successfully localized seismic noise sources and characterized wave propagation properties.
- This technique offers a valuable tool for geophysical and environmental monitoring.
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