ytvågor

Ytvågor, commonly referred to in English as surface waves, are waves that propagate along and are concentrated near the interface between two media. They are characterized by motion that decays with distance from the boundary into each medium and by a propagation speed that depends on the properties of the boundary and media.

In fluids such as oceans, surface gravity waves arise from gravitational restoring forces, with short-wavelength capillary waves stabilized by surface tension. The dispersion relation for gravity-capillary waves links phase speed to wavelength and depth; in shallow water, the speed approximates sqrt(g h).

In geophysics, surface waves travel along the Earth’s surface and along interfaces within the crust. Love waves involve horizontal shear motion, while Rayleigh waves combine longitudinal and vertical motion in an elliptical path. They typically transport significant energy and may dominate ground shaking in earthquakes at certain sites.

Electromagnetic surface waves can exist at metal-dielectric or other interfaces, including surface plasmon polaritons, which confine light to subwavelength scales and enable sensing and nanophotonic devices. These waves rely on boundary conditions for the electromagnetic field and material permittivity.

Ytvågor are studied across disciplines to understand wave propagation, coastal dynamics, subsurface imaging, and nondestructive testing. They are measured with instruments suited to the domain, such as buoys and radar for water waves, seismographs for Earth waves, and optical or near-field probes for optical surface waves.