Which waves cause a particle motion that is back and forth in a direction parallel to the wave motion?

Which waves cause a particle motion that is back and forth in a direction perpendicular to the wave motion? Which waves are called compression waves because they compress and extend the material they pass through?



Also, does anyone know any good sites where you can learn about earthquakes?Which waves cause a particle motion that is back and forth in a direction parallel to the wave motion?Read all about waves.

Mainly there are 4 types of waves generated by earthquakes. 1. Primary wave or compression wave. The speed of this wave will be in the order of 13 to 17 km per second the fastest of all waves. This wave will travel through all mediums like solids, semisolids and liquids. This will make the particles of the earth to expand and compress .The strength of this wave will be about one tenth of secondary wave. Therefore we may not feel it. Somebody may feel giddiness. Only the instruments will sense these waves. It will move the particles in the direction of its propagation.. 2. Secondary wave travels about half of the speed of primary wave. The correct ratio is 1.7 :1 This causes the earth to move in perpendicular to the direction of its propagation. The shaking will be felt by human. This wave will not travel through liquids. This is also called body waves. The above 2 waves are generated from the point called focus. That is the point where the earthquake starts. Therefore these waves are called body waves. 3. Love wave the name of the person found the wave. This is generated at the surface of the earth due to reflection and refraction of the body waves. This will generate only lateral movements. This will cause the waters to move in sideways. The water in small tanks and ponds will spill out and will become muddy. 4. Rayleigh wave most dangerous of all .These waves comes at last which generates rolling movement of the earth. These two waves are called surface waves. The shaking during earthquake will be about 1mm to 70 mm for ordinary earthquakes and it may go up to 240 mm in extraordinary cases. The Richter scale 3 will shake the earth for 0.1 mm if it is measured at a distance of 100 km from epicenter. This shaking will increase by ten fold for each Richter scale and reduce by inverse square of distance.Which waves cause a particle motion that is back and forth in a direction parallel to the wave motion?P-Waves are compression waves. The direction of the particle displacement is the same as the direction of wave propagation.



S-Waves are shear waves. The direction of the particle displacement is perpendicular to the wave motion.



A good place to start learning about quakes is from the USGS Quake web site. http://earthquake.usgs.gov/