The  Bam  earthquake  of  26  December  2003  (Mw6.5)  occurred  at 01:56:56  (GMT,  05:26:56  local  time)  around  the  city  of  Bam  in  the  southeast  of  Iran.  The  Bam  earthquake  of  26/12/2003  (Mw6.5)  has  
demolished the city of Bam, having a population of about 100000 at the time of the earthquake. The Bam fault  -  which  was  mapped  before  the  event  on  the  geological  maps  -  has  been  reactivated  during  the  26/12/2003  earthquake.  It  seems  that  a  length  of  about  10km  (at  the surface)  of  this  fault  has  been  reactivated, where it passed exactly from the east of the city of Bam.  The fault has a slop towards the west and the foci of the event was located closed to the residential area (almost beneath the city of Bam). This caused  a  great  damage  in  the macroseismic  epicentral  zone;  however  the  strong  motions  have  been  attenuated  very  rapidly, specially  towards  the  east-and  west  (fault  normal)  direction.  The  vertical  directivity  effects  caused  the  amplification  of  the  low  frequency  motions  in  the  fault-normal  direction  as  well as the greater amplitude of the motion on the vertical direction.