Particle velocity is the velocity of a particle in the ground as a vibration
disturbance passes by. Not to be confused with propagation velocity which
is the travel velocity of the vibration. Whenever a material is vibrated,
its particles experience displacement, velocity and acceleration.
The modern blasting seismograph directly measures particle velocity, usually
given in units of in/sec or mm/sec. The measurement is made in three
mutually perpendicular directions called the radial (longitudinal), vertical and
transverse. Each vibration will have a greatest amount of particle
velocity on each of the three channels. The peak particle velocity is the
largest of these three values. |