TYPES OF SEISMIC WAVES
● Seismologists identified four types of seismic waves: P-waves, S-waves,
L-waves, and R-waves.
● P- and S-waves are classified as body waves since these waves travel
across Earth's interior.
● Surface waves, the L- and R-waves, are waves that travel and are felt on
the surface/crust alone. Surface waves are actually the vibrations that we
feel when an earthquake strikes. Each of these seismic waves has its
distinct characteristics.
BODY WAVES
● P-waves, also called primary waves, are the first to be recorded by a
seismograph because they are high-frequency seismic waves. They travel
in all types of medium: solid, liquid, and gas. P-waves are compressional
waves that affect rock masses by moving them back and forth or by
alternate compression and decompression. P-waves cause relatively
small displacements of the ground since the direction of their propagation
is angled mostly within Earth's interior.
● S-waves, also called secondary waves, are shear waves of high frequency
and the second to be detected by a seismograph. They travel only in solid
medium. When S-waves pass through the ground, rock masses move
perpendicular to the direction of the waves. S-waves produce the most
damage to buildings, highways, and other infrastructures. Just like
P-waves, S-waves travel within Earth's interior.
SURFACE WAVES