Approximately, what are the dominant frequencies for reflections in Figure 6.19a that arrive at the right side of the section at about 0.6, 1.2, and 1.8 s?
Resolution is discussed in problem 6.18 where it is shown that the resolvable thickness is .
Measuring peak-to-peak time intervals for several cycles on an enlarged figure, we get periods of about 20, 30, and 40 ms, or frequencies of 50, 33, and 25 Hz, for the three reflections.
If the velocities at these reflectors are 2.0, 3.0, and 5.0 km/s, respectively, what are the resolvable thicknesses?
Resolvable thicknesses are about . This yields thicknesses of 10, 23, and 50 m, respectively.
|Previous section||Next section|
|Dependence of resolvable limit on frequency||Causes of high-frequency losses|
|Previous chapter||Next chapter|
|Geometry of seismic waves||Characteristics of seismic events|
Also in this chapter
- Characteristics of different types of events and noise
- Horizontal resolution
- Reflection and refraction laws and Fermat’s principle
- Effect of reflector curvature on a plane wave
- Diffraction traveltime curves
- Amplitude variation with offset for seafloor multiples
- Ghost amplitude and energy
- Directivity of a source plus its ghost
- Directivity of a harmonic source plus ghost
- Differential moveout between primary and multiple
- Suppressing multiples by NMO differences
- Distinguishing horizontal/vertical discontinuities
- Identification of events
- Traveltime curves for various events
- Reflections/diffractions from refractor terminations
- Refractions and refraction multiples
- Destructive and constructive interference for a wedge
- Dependence of resolvable limit on frequency
- Vertical resolution
- Causes of high-frequency losses
- Ricker wavelet relations
- Improvement of signal/noise ratio by stacking