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components.
                                                                                      given
                                                                             Love
                                                                         waves,  so
       197
                                                                             between
                                                                                      a
                                        Interference  of Love  and  Rayleigh
                                                     Interference  of Love  and  Rayleigh
       Earthquakes
                                                                                      In
                                                                south-southeast
                                                                 arrivals  of
                                                                         Rayleigh
                                                                                      focus.
                                                                   waves.
                                                                           east-west
                                                                             interference
           %
                                                                   Rayleigh)
                                                                                      the
                                                                 to
                                                                         than
                                                                  three  seismometers,  responding
       of
                               Only  Rayleigh
                                                                an  earthquake  located
                                                                                      from
       Characteristics
                                                                           and
                =P
                                                                         faster
                                                                   =
                                                                           north-south
                                                                             to
                                                                                      outward
                                                                   Love,  R
                                                                         slightly
                                                                             due
                                                                             complex,
                                                                   =
                                                                                      radiate
                                                                   (L
                                                                         travel
                             R
                                                                   surface
                                                                           the

                                                                from
                 R)
                                       «<i
                (L,
                                                                           on
                                                                         waves
                                                                paths
           =
                                                                             more
                             S
                                                                                      P-waves
                                                                   shear)  and
                                                          4  1  '  1  '  1
                                                                  of  the
                                \
           Zz
                                                                           initially
           z
                                                                wave
                                                                             is
                                                                         Love
                                                                  from  each
                                                                             pattern
                                                                                   Mechanisms
                                          j.__
                                                                Body  and  surface
                                                                                      occurs,
                             Ff
                                                                           appear
                                                                   S  =
                                                           7
                                                            First  Motion
                                          First  Motion
                                 Up—~
                                           North~_
                                                                         (Fig.  7.12b).
                                First  Motion
                                                                   compressional,
                                                              West
                                                                  of  a  station.  b)  Seismograms
                                                                             wave
                                                                                      earthquake
                                                                           waves
                                                                               waves.
                                             (N)
                                                         (E)
                                                                             surface
                                                           Component
                                               Component
                                     Component
                                   Vertical (Z)
          &
                                                                a)
                                                                                   Focal
                                             North-South
                                                                         wave
                                                                           Love
                                                         East-West
                                                                               Rayleigh
                                                                   =
                                                                7.12
                                                                   body  (P
                                                                                      an
                                                                             later
                                                                         Rayleigh
                                                                           only
                                                                                   Earthquake
                                                                FIGURE
                                                                                      When
                                                                           that
                                                                   the
                              b
                                                                               and
                                                                             The
           &
                                                                           :
                                                                             may
              “
                                             ;
                              :
                                   ;
                                                                                        surface  followed  (compression),   front   in  material  compress   first  might   wave   the  direction,   might   wave   the  direction,  another   In  (dilatation).  material   the   of  stretching  apart   by   seis-   as   station   a   at  Earth   the   from   out  coming  P-waves   first   from  compress.  The   then   and  stretch   the   (dilatation)  downward   or  (compression)  upward
                                                     motion  ata                Figs.  3.8,  3.12).   wave.  compressional   and   body   of   differently  respond   waves   by   taken   an   For   for  (seismograms)   initial   The   7.12.   came  P-wave   the   motions   First   compression   come   have   must   Love   for   Z-component   the
                                                     three  orthogonal  components  of  ground   body  waves  (see  also  horizontal  shear  wave;  P   =   motions  particle   the   seismometers   paths  different   the   motions.  particle  different   recordings   in  illustrated   Fig.   revealing  upward,   that   the  upward.  ground   show   the   that   therefore   wave   the   Z-component)   (no  motion   on  appearing
       Seismology                                                                 particle  motions  for  surface  and   =   of   view  simplified   three  3.  The   to   due  station,   the   as   well   station,   the   of   patterns   the   is  Z-component   pushing   components   E-W   westward;  than   up-down   no   wave  surface   of
       Earthquake                                    Seismographs  measuring  the   Simplified  vertical  shear  wave;  SH   =   shows   a   Chapter   in   arrive   the   at   as  station,   south-southeast   show  would   the   on   compression,   a   as   and   N-S   the   northward   is   there   that   type  only   the
       Chapter 7                                     7.10   seismic  station.   7.11  FIGURE   shear  wave;  SV   7.11   Fig.   explained  waves   waves   mic   the   to   focus   occurring   seismometers   motion)   (first   ground   the   on  P-wave   more  ground   direction.   SSE   Notice   3.12);   (Fig.
       196                                           FIGURE                       =   S
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