Hence actual particle motion is extremely complex. While the various wave types shown above have been isolated for illustration purposes, all are present to some degree whenever seismic energy is traveling through a solid medium. Many Earth tremors are of such low magnitude they are not noticed by us. When this happens, waves of energy are released and if strong enough, cause the surface of the Earth to tremble noticibly. They are caused when rock breaks or is deformed. Love waves are the most destructive waves in earthquakes because of their high amplitude and transverse particle motion. Seismic waves are mechanical vibrations that occur inside the Earth. While the particle motion is similar to that of shear waves, Love wave amplitude is much higher and decreases rapidly with depth. Love Waves are created when particles vibrate perpendicular to the propagation direction:.At depth, the motion can reverse to prograde. seismic records and estimates the amount of energy released at the source of an. A seismic energy source is used to produce seismic waves that travel through subsurface of the earth and are eventually reflected back by various subsurface. In the near surface, this motion is “retrograde”, meaning that it is counter-clockwise when the propagation is left-to-right. Two main groups of seismic waves are generated during an earthquake: (1). Rayleigh waves are characterized by elliptical motion perpendicular to the surface:.Like body waves, they are characterized by particle motion. Due to its electrodynamical nature, SHock generates high frequency energy pulse, which results in high resolution seismic gathers suitable for very accurate. Surface Waves, as the name implies, travel primarily along the ground surface amplitudes decrease rapidly with depth. ![]() The velocities of both can be measured via seismic refraction. Taken collectively, p- and s-waves are known as “body” waves. Shear Waves (“s” waves) are characterized by particle motion that is perpendicular to the propagation direction:.Compressional Waves (“p” waves) are identical to sound waves – the particle motion is parallel to the propagation direction:.There are four main types of seismic waves, each characterized by its specific particle motion: In a homogeneous medium, the wave front can also be described as a surface of constant phase. ![]() The seismic trace, which is what is recorded by the seismograph, represents particle motion vs. In a homogeneous medium, a surface drawn through points of equal travel time is spherical, as depicted in the animation below. It is the surface connecting points of equal travel time from the source. A seismic wave front emanates from an energy source like ripples on a pond, but in three dimensions.
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