Fig. 10
From: Earthquakes in Switzerland and surrounding regions during 2012
Displacement seismograms of the ML 4.2 earthquake of Zug recorded at two accelerographs in the city of Lucerne. Epicentral distance to both stations is about 21 km, distance between stations is about 1.6 km. To stabilize the double integration of the original accelerograms, the signals where filtered with a 0.5 Hz, 4th order, zero-phase high-pass Butterworth filter and detrended with a second order polynomial. Note the impulsive unilateral signal pulse of the S-phase on the two horizontal components at station SLUB (right), situated on hard rock, compared to the long duration reverberations of the S-phase at station SLUW (left), situated on unconsolidated sediments near the lake shore. Note also the amplification by a factor of 2 of the peak displacement (given below each trace in mm) at station SLUW compared to station SLUB