jl
jl
The above seismograms were recorded at 20 samples per second from a Geotech KS54000-0103 broadband three component seismometer at 119 meters depth in the Glasnost borehole near Leonard. Leonard is 10,600 kilometers (great circle) from the epicenter. The seismograms were filtered with a 0.0002 to 0.0625 Hertz filter to emphasize long period arrivals. lz is vertical earth velocity. The horizontal earth velocity was recorded in North-South and East-West directions. These traces were rotated (by trigonometry) to show lr and lt. lr (radial) is horizontal motion in the direction of the epicenter. lt (transverse) is horizontal earth velocity ar right angles to the direction of the epicenter. The familiar P (primary, longitudinal, push-pull), and S (transverse, secondary, shake) body waves are clear. Also the LQ (Love), and LR (Rayleigh) surface waves are seen. The analysis software labels the arrivals on all three components, wheither or not a given arrival is seen on all three. ADDED 2008-01-30. Mr. Gerhard Witoseek at LMU-Munich pointed out that marking all arrivals on all traces was somewhat confusing. I used an image editor (open/free Image Magick) to remove inappropriate labels, and also to add some additional phases. Of the surface waves, LQ is seen exclusively on the lt seismogram, and LR is seen exclusively on the lz and lr seismograms. SS is a two segment S wave reflected once from the earth's surface midway between the epicenter and Leonard. SKKP is an S wave converted to a P wave at the core-mantle boundary, then reflected back through the core and passing again through the mantle. The arrival just before LQ ot the lt seismogram is an SKKS arrival. It is not labelled due to the crowding of the other labels.