反射地震学是迄今为止最有效的一门地球物理技术。地壳内部的结构能反射来自地表震源的压力波,例如由载重200吨的卡车从地面上开过或海中可控爆破所产生的压力波。地球物理学家们能用灵敏的地音器测到这些反射波并把它们记录到磁带上。如果系统地移动激震源和接收器(在海上把仪器置于船后拖曳是很简单的一种办法),地球物理学家们就可以采集到这些反射波的详细数据。然后,经过计算机处理和绘图,他们就可以画出沿地表的距离对返回时间的关系曲线,并得到地壳上部(一般地表下至少5公里,有时更深些)的部分图像。石油地质学家们利用“地震反射剖面”技 Reflective seismology is by far the most effective geophysical technique. Structures inside the crust can reflect pressure waves from surface sources, such as pressure waves generated by ground-borne or controlled explosions in trucks in a 200-tonne truck. Geophysicists can detect these reflected waves with sensitive microphones and record them on magnetic tape. If you systematically move the source and the receiver (towing the instrument behind the boat at sea is a simple solution), geophysicists can capture detailed data on these reflected waves. Then, after computer processing and plotting, they can plot the distance from the surface to the return time and get partial images of the upper crust (typically at least 5 km and sometimes deeper). Oil geologists use “seismic reflection profile” technique