Translations:Seismic tomography - book/4/en

What is the first step in tomography? The first step is data gathering: Seismic traveltimes for various source/receiver positions are measured (Figure 7). This procedure is time-consuming because often a geophysicist must pick a multitude of events from the seismic data manually to determine the required traveltimes. For well-behaved seismic data, computer tracking programs can make the picks automatically, thereby greatly decreasing the effort expended by the geophysicist. However, even with good data, the traveltimes resulting from automatic picking programs have to be inspected visually for quality control.