Shown below is an example seismic record section. Offset increases from right to left. The way in which the ground motion is plotted is a little different from what we are used to looking at. In these plots, we have filled in all of those portions of the trace that are above zero with black. Plots of this type are called variable area plots. We do this because it makes it much easier to correlate similar features in the ground motion from trace to trace.
Using the left mouse button, you may select what you think are the times of arrivals on each trace. If you do not like one particular selection, you may click and drag it to a new location. If you do not like any of your selections, you may push the clear all button to erase all of your picks. After you have made your selection, bush the display my picks button to display the picks that I have made. Note that I do not know for sure that my picks are correct. These are just the times, given my experience picking first arrivals, that I would choose.