As part of a program to measure in situ acoustic parameters of sediments, transducers capable of measuring shear-wave speed and attenuation in laboratory sediments have been designed and fabricated. Transducers consisting of an array of ceramic benders have been found to be the most useful in measuring shear-wave parameters of high-porosity laboratory sediments. Measurements of shear-wave speed and attenuation in kaolinite clay sediments have been made using the ceramic bender transducers. These clays exhibit calculated shear moduli as low as 1.7×105 dyn/cm2 with shear-wave speeds from 2 to 40 m/s and attenuations from less than 100 dB/m to more than 500 dB/m.

A new type of shear wave transducer has been developed at Applied Research Laboratories, The University of Texas at Austin (ARL:UT), as part of a program to measure the acoustic parameters of marine sediments. The transducers consist of a ceramic bender element which can be immersed in the medium and has favorable characteristics for the study of the acoustic parameters of unconsolidated sediments.

The compressional wave speed and attenuation and the shear wave speed and attenuation of unconsolidated artificial laboratory sediments have been measured as a function of temperature. No overburden or pore pressure in excess of that found at a few centimeters depth was applied. The compressional wave speed of the sediment was found to vary approximately as would water. Shear wave speed appears to be independent of temperature within the accuracy of the measurement. Attenuation of both types of acoustic waves was also found to be independent of temperature.

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