Långperiodvågor

Långperiodvågor, also known as long-period waves, are a type of oceanic wave characterized by their lengthy periods, typically ranging from minutes to hours. These waves are distinct from shorter-period wind-generated waves and are often associated with more distant or significant energy sources. In meteorology, the term can refer to atmospheric waves with similar long periods.

The generation of långperiodvågor can stem from various phenomena. Seiches, standing waves within a confined body of water like a lake or harbor, are a common example. Tsunamis, generated by underwater earthquakes or volcanic eruptions, also exhibit very long periods and are a form of långperiodvågor. In coastal areas, the interaction of shorter waves with bathymetry can also create longer-period infragravity waves.

The effects of långperiodvågor can be substantial, particularly in harbors and along coastlines. They can cause significant water level fluctuations, leading to increased mooring forces on vessels and potentially inundating low-lying areas. Their long periods mean they can penetrate far into harbors and influence the dynamics of enclosed water bodies. Understanding and predicting these waves are crucial for coastal engineering, maritime safety, and tsunami warning systems.