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The above seismograms were recorded at 20 samples per second from a Geotech KS54000-0103 seismometer at 119 meter depth in the Glasnost borehole near Leonard (bz), and at 40 samples per second from a Geotech GS-13 seismometer (sz) in the walk-in vault near Leonard. This eight second segment shows clearly three P wave arrivals. Pn was refracted along the top of the upper mantle, Pb was refracted along the top of the crust's lower layer (or second layer, or Basaltic layer), and Pg travelled through the crust's upper layer (or top layer, or Granitic layer). The paths are shown in the diagram below (the diagram was actually scaled for an earthquake to station distance of slightly over 200 km.; the earthquake to station distance of this quake was 284 km.). The three arrivals are very clear in the bz seismogram. In the sz seismogram (which will show frequencies up to 16 Hertz; the bz shows only up to 8 Hertz) there appear to be as many as five to six arrivals. This tells us that the real crust may be more complicated than the simple two layers over a mantle. Also one or more of the arrivals may be reflections.
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The above broad band vertical seismogram (recorded at 20 samples per second from a Geotech KS54000 borehole seismometer at 119 meter depth) shows 150 seconds, including P and S arrivals from the 1995 SEP15 Woods County earthquake. Three P arrivals are seen as in the seismograms at the top of this page, but only one label (Pn) for a P phase is shown.