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(Ss)  euly  jeaes,  AByy-OM{
            119                                                             SQ   ~~   N   )®   NV   })   ©   during   the  middle  of  the   ‘is


            Waveform                            Primary  Events   Phase   In   =—  Muttiple   out  of Phase   of  two  primary   traces,  the   time.  the  same   completely  removed   the  water  bottom  at   Studies  in   of  Petroleum



           Seismic               Correction                    diagram   the  gathered   On   arriving  at about   ¢   x   occurs  at  2.5  s  in   of  the  section   Tectonic  Structure,  of  the  American  Association


                                 Tyo   x=                      Raypath  up  the  two  primary  reflections  in  phase,  while  miss-aligning   multiple  was  not   reflection   side  time  section  from  Middle  America  Trench.  From  The  Middle  American  Trench,  by
                                 6)  After                      the  shallower  interface.  b)                 the  left   Convergent  Margin


                                                    Zt,        multiple  reflections.  a)   the  deep  primary  reflection   water  bottom   ‘
                                                       1st  Primary   2nd  Py   Multiple   vs.   from   line       time,  or  5.0  s.  Similarly,  on   Seismic  Images  of Modern  1986.  Reprinted  by  permission
                                                       ‘   rimary


                                Correction                     of primary   reflection  multiple   than  moveout   will       Water  bottom  multiple  on  stacked  seismic  section.  The  it  overprints  deeper  primary  events.  The   the  travel   Huene,  ©



                                Tyo   a                       Discrimination   a  surface                     at  twice
                             1/4                                  has  more  normal  Proper  stacking  velocity  selection
                                Before
                             UM                               5.18                                            the  multiple  2.25  s,  the  multiple  at  4.5  s.  Unmigrated  B.  P.  Collins  and  J.  S.  Watkins,  p.  31,  in   No.  26.,  ed.  by  R.  von
                                b)                              reflections  and   the  multiple.                    Geologists. Tulsa,  Oklahoma.
                                                    2ty       FIGURE   multiple   c)                       5.19   processing,  so  that   section,  with


                                                                                                           FIGURE   Geology











                                                                         water-     pro-   is   seismic   5.20a),   strong   the   1)   source;   seis-   and   energy,   begin   those
           Analysis                                             reflections.  a)   the   is   traces   energy   a   (Fig.   a   the   the   by   acquisition   seismic   that   2)   and   phase).


           Waveform   xySS                                               example   5.19).   seismic   on   Seismic   encountered;   reflections   generate   seismic  trace  are:   of  spectra   encountered   the   generate   those   1)   phase);   (zero



           And                                                     the  primary  reflection.   An   (Fig.   observed   materials.   is   no   have   would   individual   and‘phase   are   through   sources.   to   section:   (minimum   half  after
           Processing,                                                   event.  primary   profiles   Z   (waveforms)   Earth   of   properties   would   materials   of  an   that  Earth   introduced   other   and   used  sources   seismic   final   event   and  event



           Acquisition,                                         diagrams  and  shotpoint  gathers  for  primary  and  multiple  (surface)  multiple,  resulting  in  an  event  distinct  from  the  primary  reflection.  multiple,  resulting  in  interference  with   the   as   marine   on   patterns   thicknesses   acoustical   medium   different  vastly   appearance   frequency   the   on   the  within   varieties,   cultural   from   of  artificial   the   on   reflected   the   of



           Reflection:   Multiple                                        dip  apparent   observed  commonly   interference   and  compositions   of  differing  material   homogeneous   a   separating   5.20b).   the  determine   dependent   impedance   many   of   noise   as   well   as   kinds  many   represented   are   of   time   the   at   the   at   pulse


           Seismic   118   5  Chapter   Long-Path   a)          Raypath   5.17  FIGURE   Long-path   (“peg-leg”)  b)  Short-path   the   twice   and   time   multiple  bottom   WAVEFORM  SEISMIC   and  Amplitudes   to   clues   vide   a   when  reflected   from  resulting   trace   interface   an   while   (Fig.  reflection   that  Factors   signal,  seismic   input   acoustic   in  changes   2)   3)   and   signal;   mic   procedures  processing   signal  seismic   Input   are   the
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