Which is faster for distant stations, direct or critically refracted waves?
Animation shows the race between the direct seismic wave vs. the deeper, longer-path critically refracted seismic wave. Graph records the arrival times.
Using the same seismic ray paths, the animation below adds a graph to see how data recorded show the distance transition of first arrival wave paths. Seismic stations light up BLUE when hit by direct wave, and RED when hit by the critically refracted wave.