| 摘要 |
<p>Title of the Invention SEISMIC EXPLORATION USING COMPRESSIONAL AND SHEAR WAVES SIMULTANEOUSLY In a method of seismic exploration using sweptfrequency signals, compressional and shear waves are emitted simultaneously. Typically the waves are generated by swinging-weight vibrators acting through a single baseplate. If the frequency of the shear vibration is onehalf that of the compressional vibration, the downward vertical forces can be phased to minimize the horizontal slippage of the baseplate. The sensitive axis of the geophones is inclined to the vertical for detecting both compressional waves and shear waves. For defined ranges of sweep rate, separate compressional and shear records are obtained by cross-correlating the geophone signal separately against the vertical and horizontal emissions.</p> |
