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在两口深井中进行的地震测量试验证明,横波比一般认为的重要得多。波的测试是按照现在称为“垂直地震剖面”的方法沿垂直线记录的。得到了下面几点成果:(1)证明横波(S波)可直接由井中炸药爆炸产生或者由纵波(S波)产生。(2)证明S波后面会引起P波。S波产生的证据是相当确实的。假如我们说在炮点邻近只有P波形成,那末,某些S波则在半径10～100英尺内形成。我们称这些波为直接S波或“源S波”。还有一些S波是在离开炸药震源几百英尺或几千英尺的界面上由P波能量转换为S波能量而形成。S波转换为P波的证据与P波转换为S波的波的证据相比不太明显。在炮点附近形成的源S波具有长周期的特点,周期数受炮点附近的地层控制。出现较晚的PS转换波与形成它们的P波相似。一次反射与多次反射或转换波的互相干涉在井的深部点上将形成复杂的信号,在这些点上需要从波的传播方向来鉴别上行波和下行波。
Seismic measurements conducted in two deep wells have shown that shear waves are much more important than what is generally believed. The wave test is recorded along a vertical line in what is now called a “vertical seismic profile.” The following results are obtained: (1) It has been proved that shear wave (S wave) can be generated directly from explosives in well or from longitudinal wave (S wave). (2) Prove that S waves will cause P waves behind. The evidence of S wave generation is quite certain. If we say that only P-wave formation occurs in the vicinity of the shot, some S-waves are formed within a radius of 10 to 100 feet. We call these waves direct S waves or “source S waves.” Still other S waves are formed from P-wave to S-wave energy at interfaces hundreds or thousands of feet away from the explosives source. Evidence of S-wave conversion to P-wave is less pronounced than evidence of P-wave conversion to S-wave. The source S wave formed near the shot has the characteristics of long period and the number of cycles is controlled by the formation near the shot. The PS transitions occurring later are similar to the P waves forming them. Interference between one reflection and multiple reflections or converted waves creates complex signals at deep points in the well where the up and down waves need to be identified from the direction of propagation of the waves.