SEISMIC
DOWNHOLE AND CROSSHOLE SURVEYS
In order to develop detailed layer velocity
information so that engineering parameters such as
shear modulus and Poisson's ratio may be
calculated, down hole or cross hole surveys may be
performed.
These surveys employ the use of
down hole geophones and either down hole or
surface hammers, depending on the application.
Energy generated at the source propagates to the
geophone in the form of compression or shear waves
which are recorded and stored on a seismograph on
the surface.
