Related Experiment Video
Updated: Jun 21, 2026
08:54
Measurements of Waves in a Wind-wave Tank Under Steady and Time-varying Wind Forcing
Published on: February 13, 2018
Phase statistics of seismic coda waves.
D Anache-Ménier1, B A van Tiggelen, L Margerin
1Laboratoire de Physique et de Modélisation des Milieux Condensés, Université Joseph Fourier/CNRS, BP 166, 38042 Grenoble, France.
Physical Review Letters
|August 8, 2009
Summary
Seismic coda phase fluctuations follow universal power-law decays, matching Gaussian statistics. This analysis helps estimate the mean free path of Rayleigh waves, crucial for understanding seismic wave propagation.
Area of Science:
- Seismology
- Wave Propagation Physics
Background:
- Seismic coda waves contain valuable information about Earth's subsurface structure.
- Understanding seismic wave scattering is key to interpreting earthquake recordings.
Purpose of the Study:
- To analyze phase fluctuation statistics in earthquake seismic coda.
- To compare observed distributions with theoretical statistical models.
- To estimate the mean free path of seismic waves.
Main Methods:
- Deployment of a temporary seismic experiment at Pinyon Flats Observatory, California.
- Statistical analysis of seismic coda phase fluctuations.
- Measurement of the phase derivative correlation function.
Main Results:
- Observed distributions of spatial phase derivatives exhibit universal power-law decays.
- Exponents of these power laws accurately agree with circular Gaussian statistics.
- The correlation function provided an estimate for the mean free path of Rayleigh waves.
Conclusions:
- Seismic coda phase fluctuations are well-described by universal statistical laws.
- Circular Gaussian statistics accurately model these phenomena.
- The study provides a method for estimating the mean free path of Rayleigh waves from coda analysis.
Related Concept Videos
01:10Wave Parameters
The simplest mechanical waves are associated with simple harmonic motion and repeat themselves for several cycles. These simple harmonic waves can be modeled using a combination of sine and cosine functions. Consider a simplified surface water wave that moves across the water's surface. Unlike complex ocean waves, in surface water waves, water moves vertically, oscillating up and down, whereas the disturbance of the wave moves horizontally through the medium. If a seagull is floating on the...
01:17Standing Waves
Sometimes waves do not seem to move; rather, they just vibrate in place. Unmoving waves can be seen on the surface of a glass of milk kept in a refrigerator, which is one example of standing waves. Vibrations from the refrigerator motor create waves on the milk that oscillate up and down but do not seem to move across the surface. These waves are formed or created by the superposition of two or more identical moving waves in opposite directions. The waves move through each other, with their...
01:03Modes of Standing Waves - I
A close look at earthquakes provides evidence for the conditions appropriate for resonance, standing waves, and constructive and destructive interference. A building may vibrate for several seconds with a driving frequency matching the building's natural frequency of vibration; this produces a resonance that results in one building collapsing while the neighboring buildings do not. Often, buildings of a certain height are devastated, while other taller buildings remain intact. This phenomenon...
01:16Shock Waves
While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the source's speed through it. When this condition is breached, a shock wave occurs.
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
01:28Standing Waves in a Cavity
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
01:04Modes of Standing Waves: II
The starting point for expressing the modes of standing waves is understanding the boundary conditions that the waves must follow. The boundary conditions are derived from the physical understanding of how the standing waves are sustained, that is, how the vibrating particles of the medium behave at the boundaries imposed on them.
For a tube open at one end and closed at the other filled with air, the modes are such that there is always an antinode at the open end and a node at the closed end.
For a tube open at one end and closed at the other filled with air, the modes are such that there is always an antinode at the open end and a node at the closed end.