Experimental techniques have been developed to study the propagation of large-amplitude, one-dimensional shear and compression waves in shocked solids of geophysical interest. Shear wave velocities and amplitudes can be directly measured along with the usual measurements on longitudinal waves. Although shear wave amplitude measurements do not approach the quality of the compression wave data, shear wave velocities can be measured to a precision of better than two percent. Experimental measuremetns to 90 kbar compressive shock stresses are reported in Al2O3. Within experimental scatter (¿2%), our shear wave velocity data are in good agreement with the extrapolation of the ultrasonic measurements. The longitudinal measurements are in good agreement with earlier work. The experimental developments reported here are expected to be important to high pressure geophysics applications because they provide a direct measure of the shear modulus in the shocked state. The shear modulus is not only a more sensitive indicator of the solid state than the longitudinal modulus but in conjunction with the longitudinal wave data can provide the mean stress-volume relations for comparison with static data.