U.S. DEPARTMENT OF THE INTERIOR / U.S. GEOLOGICAL SURVEY
                                
                                
        U.S. GEOLOGICAL SURVEY DIGITAL DATA SERIES DDS-13
                                
              International Phase of Ocean Drilling
                Seismic Line 1 Demultiplexed Data
               Cape Hatteras to Mid-Atlantic Ridge
                                
                            DISC ¯14

Demultiplexed Seismic Data

     Each file of seismic data is the disc-image of a SEG-Y
format tape output during the demultiplexing of the original
field data.  The data were written to tape using the 32 bit IBM
floating point format (Barry, and others, 1975).  As the data
were copied bit-for-bit to the CD-ROM file, this format was
preserved.  Each file of sesimic data is named IPD{number}, where
{number} is the first shotpoint in the file.  NOTE: FFID
indicates the Field File Identification Number assigned each shot
as it was recorded.

             file:  ¯IPD8695.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯132102260
   traces in file:  ¯24265
      first trace:  ¯592/44 FFID/trace
       last trace:  ¯92/20 FFID/trace


             file:  ¯IPD8948.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯9688476
   traces in file:  ¯1779
      first trace:  ¯98/21 FFID/trace
       last trace:  ¯135/23 FFID/trace


             file:  ¯IPD8967.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯132162144
   traces in file:  ¯24276
      first trace:  ¯135/24 FFID/trace
       last trace:  ¯641/11 FFID/trace

                             1


             file:  ¯IPD9220.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯48025124
   traces in file:  ¯8821
      first trace:  ¯641/12 FFID/trace
       last trace:  ¯844/48 FFID/trace

             file:  ¯IPD9229.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯130980796
   traces in file:  ¯24059
      first trace:  ¯813/1 FFID/trace
       last trace:  ¯334/11 FFID/trace

             file:  ¯IPD9556.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯132510560
   traces in file:  ¯24340
      first trace:  ¯334/12 FFID/trace
       last trace:  ¯841/15 FFID/trace

                             2


Observer Logs

     The following files are digitized versions of the original
observer's log sheets.  Each file is named OB{number}.{format},
where {number} is the first shot point on the page, and {format}
is the graphic format of the file: PCX, TIF, or GIF.  No {format}
extension is shown with the file names given below.

OB8681
OB8731
OB8781
OB8831
OB8881
OB8931
OB8981
OB9031
OB9081
OB9131
OB9231
OB9271
OB9321
OB9371
OB9421
OB9471
OB9521
OB9571
OB9621
OB9671
OB9721
OB9771



REFERENCE

Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended
     standards for digital tape formats: Geophysics, v. 40, p.
     344-352.



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