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Cannot find origin time in SAC header

Q: I requested some sac files using Wilber II. I noticed that the time
following the "KZTIME" header in the sac file is different from the origin
time of the event that I requested. There are no other headers indicating
the origin time. May you please let me know why this is happening and how
do I verify that this is the actual sac file for the event that I
requested.

A: I pulled up one of your SAC data files to look at the header. SAC shows the following:

SAC> read 1994.153.17.48.43.9891.II.WRAB.00.LHZ.D.SAC
SAC> listhdr

FILE: 1994.153.17.48.43.9891.II.WRAB.00.LHZ.D.SAC - 1
-------------------------------------------------

       NPTS = 2944
          B = 1.000000e-04
          E = 2.942998e+03
     IFTYPE = TIME SERIES FILE
      LEVEN = TRUE
      DELTA = 9.999994e-01
       IDEP = UNKNOWN
     DEPMIN = -2.952368e+06
     DEPMAX = 2.598185e+06
     DEPMEN = 1.062373e+04
    OMARKER = 1730
     KZDATE = JUN 02 (153), 1994
     KZTIME = 17:48:43.989
      KSTNM = WRAB
      CMPAZ = 0.000000e+00
     CMPINC = 0.000000e+00
       STLA = -1.993360e+01
       STLO = 1.343600e+02
       STEL = 3.660000e+02
       STDP = 1.000000e+02
       EVLA = -1.047700e+01
       EVLO = 1.128350e+02
       EVDP = 1.840000e+04
      KHOLE = 00
       DIST = 2.534725e+03
         AZ = 1.169120e+02
        BAZ = 2.912198e+02
      GCARC = 2.277521e+01
     LOVROK = TRUE
      NVHDR = 6
      SCALE = 1.243780e+10
      NORID = 0
      NEVID = 0
     LPSPOL = FALSE
     LCALDA = TRUE
     KCMPNM = LHZ
     KNETWK = II
        MAG = 7.800000e+00

   The hypocenter SEED blockette looks like the following, which is the source of event information that goes into the SAC header:
07101041994,153,18:17:34.0200~01-10.4770000112.8350000018.400107.80MW~010240282SOUTH OF JAWA, INDONESIA~

   What you're looking for is the OMARKER field, which is apparently the same as field 'O' in the older SAC manual I am looking at. This is the number of seconds for the event origin time relative to the reference time, which is KZTIME. The event is listed as being at 18:17:34 and the station reference time is 17:48:44 (rounded up), a difference of 28 minutes, 50 seconds. This equates to the value of 1730 seconds indicated in OMARKER.

   You will find the other event information under, EVLA, EVLO, EVDP, DIST, AZ, BAZ, and MAG.