Seiche

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Definition of Seiche:
Harbour seiches are resonant (or near-resonant) standing oscillations in a semi-enclosed water body caused by incoming long-period waves (periods typically in the range 200-2000 s).
This is the common definition for Seiche, other definitions can be discussed in the article


Notes

  • Incoming waves can be strongly amplified if the period is close to the harbour resonance period, causing damage to ships and moorings.
  • Long-period waves can be generated by nonlinear interaction of random short waves with a peaked frequency distribution (see Infragravity waves), generated mainly in shallow water and reflected from adjacent coasts.
  • Long-period waves can also be generated by meteorological effects, in particular strong wind speed fluctuations during storms, related to the passage of a cold front[1].
  • Other generation mechanisms include deep-sea internal waves, seismic activity, or tsunamis[2].
  • Seiches occur also in closed basins, such as lakes, often induced by strong fluctuations in the wind field.


Relates articles

Harbor resonance
Proudman resonance and meteo tsunamis


References

  1. De Jong, M.P.C. and Battjes, J.A. 2004. Low-frequency seawaves generated by atmospheric convection cells. J. Geophys. Res. 109(C1), C01011
  2. Giese, G.S. and Chapman, D.C. 1993. Coastal seiches. Oceanus 36: 38-46