Axial Vs on Core Samples of the KTB Pilot Hole VB1

Ultrasonic wave propagation through core samples is studied in a water tank to insure good signal transmission between transducer, rock specimen and receiver and to avoid time - consuming mechanical preparations.
A specifically designed instrumentation was used, which allows to measure the radial p-wave velocity in the plane normal to the core axis and, if the core sample is long enough, also the axial p- and s-wave velocities by common mid-point (CMP) refraction experiments, with water as the upper and the core as the lower layer. By rotating the cores, all measurements are performed for variable azimuths. Computer control of all mechanical and electronical operations, digital 10-bit data aquisition, signal stacking and interactive seismogram evaluation are essential features of the system.
Data are available from the few cores taken below 4000 m. The investigations were carried out on the longest core sample of each cored interval (16 specimens).