From Coastal Wiki
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).
- 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.
- Other generation mechanisms include deep-sea internal waves, seismic activity, or tsunamis.
- Seiches occur also in closed basins, such as lakes, often induced by strong fluctuations in the wind field.
- De Jong, M.P.C. and Battjes, J.A. 2004. Low-frequency seawaves generated by atmospheric convection cells. J. Geophys. Res. 109(C1), C01011
- Giese, G.S. and Chapman, D.C. 1993. Coastal seiches. Oceanus 36: 38-46