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 ¯19

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:  ¯IPD14112.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯131367320
   traces in file:  ¯24130
      first trace:  ¯985/1 FFID/trace
       last trace:  ¯487/34 FFID/trace


             file:  ¯IPD14242.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯8365584
   traces in file:  ¯1536
      first trace:  ¯246/1 FFID/trace
       last trace:  ¯277/48 FFID/trace


             file:  ¯IPD14363.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯132080484
   traces in file:  ¯24261
      first trace:  ¯487/35 FFID/trace
       last trace:  ¯993/7 FFID/trace

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             file:  ¯IPD14616.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯131448980
   traces in file:  ¯24145
      first trace:  ¯993/8 FFID/trace
       last trace:  ¯496/8 FFID/trace


             file:  ¯IPD14867.SGY
      sample rate:  4000.0 microsec
samples per trace:  ¯1301
      data length:  ¯5204 msec
  bytes per trace:  ¯5444
    bytes in file:  ¯132145812
   traces in file:  ¯24273
      first trace:  ¯496/9 FFID/trace
       last trace:  ¯41/1 FFID/trace

































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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 for the file names given below.

OB14100
OB14150
OB14200
OB14250
OB14300
OB14350
OB14350G
OB14400
OB14450
OB14500
OB14550
OB14600
OB14650
OB14700
OB14750
OB14800
OB14850
OB14900
OB14950
OB15000
OB15050
OB15100
























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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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