This is the same teleseismic earthquake as before, but recorded at two seismic stations around 300 km apart. There is a distinct time lag between the seismic wave arrival at the two stations, becuase one is closer the the earthquake then the other. (The bottom trace is recorded at the closer station -- see the eariler P-wave arrival relative to the top trace). The two traces are played as two different stereo channels: The bottom trace is the right channel, and the top is the left. Consequently, you hear the teleseism earlier on the right, which gives you the sense that the teleseism is approaching you from the right, travelling leftwards. In contrast, the local earthquakes are at different positions relative to the teleseism. They are closer to the station recording the top trace, so you hear them principally on the left channel, but also, faintly, on the right.
|Teleseism in stereo