Editing Wave (section)

=== Propagation===

Wave propagation is any of the ways in which waves travel. With respect to the direction of the [[oscillation]] relative to the propagation direction, we can distinguish between [[longitudinal wave]] and [[transverse wave]]s.

[[Electromagnetic wave]]s propagate in [[vacuum]] as well as in material media. Propagation of other wave types such as sound may occur only in a [[transmission medium]].

==== Reflection of plane waves in a half-space  ====
{{further|Reflection coefficient}}
The propagation and reflection of plane waves—e.g. Pressure waves ([[P wave]]) or [[S-wave|Shear waves (SH or SV-waves)]] are phenomena that were first characterized within the field of classical [[seismology]], and are now considered fundamental concepts in modern [[seismic tomography]]. The analytical solution to this problem exists and is well known. The frequency domain solution can be obtained by first finding the [[Helmholtz decomposition]] of the displacement field, which is then substituted into the [[wave equation]]. From here, the [[Wave equation#Plane-wave eigenmodes|plane wave eigenmodes]] can be calculated.{{citation needed|date=May 2023}}{{clarify|Unintelligible to the ordinary reader|date=May 2023}}

==== SV wave propagation ====
[[File:SV wave propagation.gif|thumb|upright=1.4|The propagation of SV-wave in a homogeneous half-space (the horizontal displacement field)]]
[[File:SV wave propagation y.gif|thumb|upright=1.4|The propagation of SV-wave in a homogeneous half-space (The vertical displacement field){{clarify|date=May 2023}}]]
The analytical solution of SV-wave in a half-space indicates that the plane SV wave reflects back to the domain as a P and SV waves, leaving out special cases. The angle of the reflected SV wave is identical to the incidence wave, while the angle of the reflected P wave is greater than the SV wave. For the same wave frequency, the SV wavelength is smaller than the P wavelength. This fact has been depicted in this animated picture.<ref>The animations are taken from {{cite web
 | url = https://sites.google.com/a/utexas.edu/babakpoursartip/research
 | title = Topographic amplification of seismic waves
 | last = Poursartip
 | first = Babak
 | year = 2015
 | department = UT Austin
 | access-date = 2023-02-24
 | archive-date = 2017-01-09
 | archive-url = https://web.archive.org/web/20170109184014/https://sites.google.com/a/utexas.edu/babakpoursartip/research
 | url-status = dead
}}</ref>

==== P wave propagation ====
Similar to the SV wave, the P incidence, in general, reflects as the P and SV wave. There are some special cases where the regime is different.{{clarify|unintelligible to the ordinary reader|date=May 2023}}