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 Ż22 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: ŻIPD17465.SGY sample rate: 4000.0 microsec samples per trace: Ż1301 data length: Ż5204 msec bytes per trace: Ż5444 bytes in file: Ż131269328 traces in file: Ż24112 first trace: Ż252/48 FFID/trace last trace: Ż755/15 FFID/trace file: ŻIPD17717.SGY sample rate: 4000.0 microsec samples per trace: Ż1301 data length: Ż5204 msec bytes per trace: Ż5444 bytes in file: Ż132363572 traces in file: Ż24313 first trace: Ż755/16 FFID/trace last trace: Ż261/40 FFID/trace file: ŻIPD17970.SGY sample rate: 4000.0 microsec samples per trace: Ż1301 data length: Ż5204 msec bytes per trace: Ż5444 bytes in file: Ż131301992 traces in file: Ż24118 first trace: Ż261/41 FFID/trace last trace: Ż765/14 FFID/trace 1 file: ŻIPD18222.SGY sample rate: 4000.0 microsec samples per trace: Ż1301 data length: Ż5204 msec bytes per trace: Ż5444 bytes in file: Ż132298244 traces in file: Ż24301 first trace: Ż765/15 FFID/trace last trace: Ż271/27 FFID/trace file: ŻIPD18475.SGY sample rate: 4000.0 microsec samples per trace: Ż1301 data length: Ż5204 msec bytes per trace: Ż5444 bytes in file: Ż131155004 traces in file: Ż24091 first trace: Ż271/28 FFID/trace last trace: Ż773/22 FFID/trace 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. OB17431 OB17481 OB17531 OB17581 OB17631 OB17681 OB17731 OB17781 OB17831 OB17881 OB17981 OB18031 OB18081 OB18131 OB18181 OB18231 OB18281 OB18331 OB18381 OB18431 OB18481 OB18531 OB18581 OB18631 OB18681 2 REFERENCE Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, v. 40, p. 344-352. 3