# Magnitudes of seismic wave parameters

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Series | Geophysical References Series |
---|---|

Title | Problems in Exploration Seismology and their Solutions |

Author | Lloyd P. Geldart and Robert E. Sheriff |

Chapter | 2 |

Pages | 7 - 46 |

DOI | http://dx.doi.org/10.1190/1.9781560801733 |

ISBN | ISBN 9781560801153 |

Store | SEG Online Store |

## Problem 2.8

The magnitudes of period , wavelength , wavenumber , frequency , and angular frequency are important in practical situations. Calculate , , and for 15 and 60 Hz for the following velocity situations:

- weathering, 100 and 500 m/s (minimum and average values);
- water, 1500 m/s;
- sands and shales, 2000 (poorly consolidated) and 3300 m/s;
- limestone, 4300 (porous) and 5500 m/s;
- salt, 4600 m/s;
- anhydrite, 6100 m/s.

### Solution

The period equals , so s for Hz and s for Hz. Also, , . Using these equations we get the values of and in Table 2.8a.

For Hz | For Hz | ||||||
---|---|---|---|---|---|---|---|

(km/s) | (s) | (m) | (s) | (m) | |||

Weathering (min.) | 0.1 | 0.067 | 7 | 0.7 | 0.017 | 2 | 4 |

Weathering (avg.) | 0.5 | 0.067 | 30 | 0.2 | 0.017 | 8 | 0.8 |

Water | 1.5 | 0.067 | 100 | 0.063 | 0.017 | 25 | 0.25 |

Poorly consolidated sandstone-shales at 0.75 km | 2.0 | 0.067 | 130 | 0.047 | 0.017 | 33 | 0.19 |

Tertiary clastics at 3.00 km | 3.3 | 0.067 | 220 | 0.029 | 0.017 | 55 | 0.11 |

Porous limestone | 4.3 | 0.067 | 290 | 0.022 | 0.017 | 72 | 0.088 |

Dense limestone | 5.5 | 0.067 | 370 | 0.017 | 0.017 | 92 | 0.069 |

Salt | 4.6 | 0.067 | 310 | 0.020 | 0.017 | 77 | 0.082 |

Anhydrite | 6.1 | 0.067 | 410 | 0.015 | 0.017 | 100 | 0.062 |

## Continue reading

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Sum of waves of different frequencies and group velocity | Potential functions used to solve wave equations |

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Introduction | Partitioning at an interface |

## Also in this chapter

- The basic elastic constants
- Interrelationships among elastic constants
- Magnitude of disturbance from a seismic source
- Magnitudes of elastic constants
- General solutions of the wave equation
- Wave equation in cylindrical and spherical coordinates
- Sum of waves of different frequencies and group velocity
- Potential functions used to solve wave equations
- Boundary conditions at different types of interfaces
- Boundary conditions in terms of potential functions
- Disturbance produced by a point source
- Far- and near-field effects for a point source
- Rayleigh-wave relationships
- Directional geophone responses to different waves
- Tube-wave relationships
- Relation between nepers and decibels
- Attenuation calculations
- Diffraction from a half-plane