P04 bathymetry: ASCII navigation and bathymetry data files for the two legs of P04 were obtained from the WOCE CDROM (issued 1997), in National Geophysical Data Center format. WOCE designation: P04E, P04 and P04W EXPOCODE 32MW893-1 (W) 32MW893-2 (C) 32MW893-3 (E) Chief scientist: Leg 1: John Toole, WHOI Leg 2: Esther Brady, WHOI Leg 3: Harry Bryden, WHOI Ship: R/V Moana Wave Ports of call: Leg 1: Palau, Philippines to Majuro, Marshall Islands Leg 2: Majuro, Marshall Islands to Honolulu Leg 3: Honolulu to Punta Arenas, Costa Rica Cruise dates: Leg 1: Feb 6 - Mar 9, 1989 Leg 2: Mar 9 - Mar 24, 1994 Leg 3: Apr 2 to May 19, 1989 "p04e_08020053.txt", "p04c_08020052.txt", "p04w_08020051.txt" are the three original data files, NGDC format (see data format description below). "P04E_bathy_gdc.dat", "P04C_bathy_gdc.dat", "P04W_bathy_gdc.dat" are in Geological Data Center format and include corrected depths at all recorded locations. "P04_bathydist.dat" is the decimated bathymetry file, projected onto straight lines between station positions, used for plotting the vertical sections. "P04_sta_bdep.dat" is the station list, with corrected bottom depths as taken from the P04su.txt file (station summary file) "P04_sta_bpres.dat" is the station list, with corrected bottom pressures for each station, based on the P04su.txt file (station summary file) ----------------------------------------------- Format specifications Format of "p04e_08020053.txt", "p04c_08020052.txt", "p04w_08020051.txt" - see below Format of "P04_bathydist.dat" ist (iii) station number (set to 1) dist (ffffff.f) distance (km) along section lat (dddddd.mm) decimal latitude lon (dddddd.mm) decimal longitude dpt (ddddd.d) depth meters Format of P04_sta_bpres.dat and P04_sta_bdep.dat station (iiii) station number distance (xxxxx.x) km along section latitude (xxx.xxx) longitude (xxxx.xxx) pressure (xxxx.x) dbar OR depth in meters ---------------------------------- Extract from US National Geophysical Data Center document on the MGD77 format THE DATA RECORD The data record presents underway marine geophysical data in a correlative manner. Geophysical data (bathymetry, magnetics, and gravity) and seismic identification (shot-point identification) are presented with a corresponding time and position. Documentation that is variable throughout the survey also is included within each data record. If primary navigation exists at a juncture where no geophysical data are present, this record should be included with the data parameter fields left unused (9s filled). The logical record length is 120 characters. Format Conventions for the Data Record: * . All decimal points are implied. * . Leading zeros and blanks are equivalent. * . Unknown or unused fields are to be 9s filled. * . All "corrections", such as time zone, diurnal magnetics, and Eotvos, are understood to be added (e.g., time-zone correction is the number of hours which must be added to the recorded time to determine GMT). The following is a detailed description of the Data Record.Fields can be of type integer, real or character. Fields that present whole numbers are integers Fields that contain a decimal component are real, and fields that are alphanumeric are character. . Character Length Type Description Nos of Field 1 1 int DATA RECORD TYPE Set to "3" (data record.) 2-9 8 char SURVEY IDENTIFIER Identifier supplied by the contributing organization, else given by NGDC in a manner which represents the data. Identical to that in header record. 10-14 5 real In hundredths of hours. Corrects time (in characters 15-27) to GMT when added: equals zero when time is GMT. Timezone normally falls between -13 and +12 inclusively 15-16 2 int YEAR (e.g. 1972 is represented as 72) 17-18 2 int MONTH (e.g. May is represented as 05) 19-20 2 int DAY Day of month 21-22 2 int HOUR Hour of day 23-27 5 real MINUTES X 1000 28-35 8 real LATITUDE X 100000 + = North; - = South Between -90 and 90 degrees 36-44 9 real LONGITUDE X 100000 + = East; - = West Between -180 and 180 degrees 45 1 int POSITION TYPE CODE Indicates how lat/lon was obtained: 1 = Observed fix 3 = Interpolated 3 = Interpolated 46-51 6 real BATHYMETRY, 2- WAY TRAVELTIME In ten-thousandths of seconds. Corrected for transducer depth and other such corrections, especially in shallow water 52-57 6 real BATHYMETRY, CORRECTED DEPTH In tenths of meters. 58-59 2 int BATHYMETRIC CORRECTION : This code details the procedure use for determining the sound velocity correction to depth 01-55 Matthews' Zones with zone 59 Matthews' Zones, no zone 60 S. Kuwahara Formula 61 Wilson Formula 62 Del Grosso Formula 63 Carter's Tables 88 Other (see Add. Doc.) 99 Unspecified 60 1 int BATHYMETRIC TYPE CODE Indicates how the bathymetric value was obtained 1 - Observed 3 - Interpolated (Header Seq. 12) 9 - Unspecified (Note the full MGD77 format has another 60 bytes which are not used in the WOCE dataset) 10-DEGREE-SQUARE IDENTIFIER CODE A 10-degree-square area can be easily identified by constructing a four-digit number. The components of this number, in order of their construction are described as follows: Quadrant - A one-digit number identifies the quadrant of the world with the following significance to each digit: 1st digit = Quadrant number Qc Code Latitude Longitude 1 North East 3 South East 5 South West 7 North West 10-Degree Square - The next three digits identify a unique 10-degree square; thus the significant digits consist of: 2nd digit = Tens digit of degrees latitude 3rd digit = Hundreds digit of degrees longitude 4th digit = Tens digit of degrees longitude Examples 37 deg 48'S, 4 deg 13'E 3300 21.6 deg S, 14.3 deg W 5201 34 deg 28'N, 143 deg 7314 27'W 75 deg N, 43 deg E 1704 _______________________________________________ NOTES: on reformatting data ASCII bathymetry data file obtained from WOCE cdrom in NGDC's MGD77 format (11/98) reformatted to Talley's 11/30/98 Three legs: p04w, p04c, p04e Input file (ending in .txt) contains: dtyp i1 (data type) ident a8 (identification code) chr f5.2(GMT correction hrs) yr,mo,day all i2 mins f5.0 (X 1000) lat f8.5 (dec degs X 10000) lon f9.5 (dec degs X 10000) ptyp i1 (position type) btime f6.4(bathymetric travel time) dep f6.1(corrected depth) bcor i2 (bathymetric correction type) bcod i1 (bathymetric code) Output file (ending in .dec) contains: 1 (i3) d (f7.1) lat(f10.3) lon(f10.3) dep(f7.1) yday(f10.4)