Description of FFB files

This file describes the ISC's Fixed Format Bulletin (.ffb) files, which are available on the ftp site and on the Bulletin CDs. The same format is used for the Catalogue files (again, only on the ftp site or Bulletin CDs), except that phase records are excluded.

Contents


Record Sequence

Within the file the records are in the following sequence:
  • One Header record
  • Agency records
    • These are listed in order of increasing agency number. Numbers 98 and 99 are used internally and are not allocated in this list.
    • All allocated agency codes are included whether used in the current issue of the bulletin or not.
  • Station records
    • These are listed in order of increasing station number, occasionally numbers will be missing where they had been allocated to stations whose locations are not known.
    • Only stations used to prepare this issue of the bulletin are included. The locations are those used at the time of the preparation of the bulletin.
  • Groups of records associated with an event.
    • The events are listed in time order of prime estimate This is the same order as they appear in ISC printed bulletin
    • Each monthly file contains all the events whose prime estimates are within that month.

Each group of records for an event will contain records in the following sequence - The order of the records within an event is the same as in the ISC printed bulletin.

  • Non prime estimates section (optional)
  • Prime estimate section (essential)
  • Station data (optional)

Each estimate section contains records in the following sequence:

EPICENTRE RECORD(FORMAT 1) (optional)
EPICENTRE CONTINUATION RECORD(FORMAT 2) (optional)
EPICENTRE COMMENT(FORMAT 3) (optional)
EPICENTRE COMMENT CONTINUATION RECORD(FORMAT 4) (optional)

The prime estimate must contain a format 1 record. Non-prime estimates must contain either a format 1 or a format 3 record.

Phase data appears in increasing distance of the station from the prime estimate and contains records in the following sequence:


Treatment of times which fall outside the month.

Events in the last few minutes of a month will sometimes have records associated which are from the next month. These may appear in the file with a day number which follows the last day of the month. No special treatment is made for leap seconds on this file when this happens (although it is accounted for in ISC internal files) For example, a phase on 1991/01/01 at 00h 02m 03.1s associated with an event in 1990 December may have its time recorded in the 199012.FFB file as 1990/12/32 00h 02m 04.1s, the additional second being added because 1990 December contained a leap second.

Commands are continued to next line by last non-blank character being a comma.


Precisions

Precisions are an indication of the accuracy to which the parameter is known. The integer value of the precision is the power of ten which contains the last significant digit. That is, a precision of -1 indicates a value significant to one decimal place, while a precision of 0 indicates a value significant to the nearest unit.

Time, latitude and longitude have special extra precisions. A full list of precisions found with time is:

INITIAL PHASE RECORD(FORMAT 5 or 15) (essential)
LATER PHASE RECORD(S)(FORMAT 6) (optional)
PHASE COMMENTS RECORD(S)(FORMAT 7) (optional)
3to nearest 1/10th minute
2to nearest minute
1to nearest ten seconds
0to nearest second
1to 1/10th second
2to 1/100th second

Magnitude is sometimes given with precision 8, indicating that values were originally given as fractions 1/4, 1/2, 3/4.


Record Formats

Each record is described as a sequence of fields. Each field description consists, itself, of a sequence of fields, which are

  1. F
  2. record type
  3. first column number
  4. last column number in field
  5. field type
    Ix Occupies x columns - leading blanks allowed
    Fx Occupies x columns - leading and trailing blanks allowed
    Ax Occupies x columns - characters
  6. Null value
    * fixed value - can be used to identify record type
    - no null value allowed
    b null represented by field filled with blanks
    else null value
  7. values
  8. Comment

  9. Record Format 0: Header

    R  0                        !Header record - format 0
    F  0  1 -2 I2  *  0         !Record category
    F  0  3 -4 I2  -  IR        !Next record category
    F  0  5 -8 I4  -  IY        !Reference year
    F  0  9-10 I2  -  1-12      !Reference month number
    F  0 11-14 I4  -  IY        !Year - repeated
    F  0 15-16 I2  -  1-12      !Month number (repeated)
    F  0 17-19 A3  -  'Apr',    !Month name  'Aug','Dec','Feb','Jan','Jul','Jun','Mar','May','Nov','Oct','Sep'
    F  0 20-21 I2  -  1         !First day number
    F  0 22-23 I2  -  28-31     !Last day number
    F  0 24-25 I2  -  64-98     !Last two digits of creation year
    F  0 26-27 I2  -  1-12      !Creation month number
    F  0 28-29 I2  -  1-31      !Creation day number
    F  0 30-35 I6  -  1-10      !Software version
    F  0 36-38 I3  -  96        !Record length
    


    Record Format 1: Epicentre

    R  1                        !Epicentre - format 1
    F  1  1 -2 I2  *  1         !Record category
    F  1  3 -4 I2  -  IR        !Next record category
    F  1  5 -8 I4  -  IY        !Reference year
    F  1  9-10 I2  -  1-12      !Reference month
    F  1 11-12 I2  b  1-28,29,30,31,32   !Day number
    F  1 13-14 I2  b  0-23      !Hours
    F  1 15-16 I2  b  0-59      !Minutes
    F  1 17-20 F4  b  0-5999    !Seconds*100 (F4.2)
    F  1 21-22 I2  -  -3,-2,-1,0,1,2,3      !Precision of time
    F  1 23-25 I3  -  1-299        !Agency number from 'FIXED'
    F  1 26-26 A1  -  'A',        !Prime estimate flag - A=Prime, B-Z others
    F  1 27-33 I7  -  -900000-900000     !Latitude * 10**4 (F7.4)
                            !Precision of latitude
    F  1 34-35 I2  -  -6,   ! to 1/1000000th degree !!
                      -5,   ! to 1/100000th degree  !!
                      -4,   ! to 1/10000th degree   !!
                      -3,   ! to 1/1000th degree
                      -2,   ! to 1/100th degree
                      -1,   ! to 1/10th degree
                       0,   ! to nearest degree
                       1,   ! to ten degrees !
                       4,   ! degrees, minutes, seconds and tenths of second
                       5,   ! degrees, minutes, seconds
                       6,   ! degrees, minutes and tenths of minutes
                       7,   ! degrees and minutes
                       8    ! fraction of a degree (1/4, 1/2, 3/4)
    F  1 36-43 I8  -   -1800000-1800000     !Longitude * 10**4  (F8.4)
     -1800000 to   1800000  1705968     
                          !  Precision of longitude
    F  1 44-45 I2  -  -6,   ! to 1/1000000th degree !!
                      -5,   ! to 1/100000th degree  !!
                      -4,   ! to 1/10000th degree   !!
                      -3,   ! to 1/1000th degree
                      -2,   ! to 1/100th degree
                      -1,   ! to 1/10th degree
                       0,   ! to nearest degree
                       1,   ! to ten degrees !
                       4,   ! degrees, minutes, seconds and tenths of second
                       5,   ! degrees, minutes, seconds
                       6,   ! degrees, minutes and tenths of minutes
                       7,   ! degrees and minutes
                       8    ! fraction of a degree (1/4, 1/2, 3/4)
    F  1 46-49 I4  b  -100-7700,          ! Depth in kilometres *10 (F4.1)
                      7701-9000
    F  1 50-51 I2  99 -3,-2,-1,0              !    Precision of depth
    F  1 52-55 F4  b  0-99,100-199,200-299,300-399,400-499,500-599,
                      600-699,700-799,800-899,900-999  ! Magnitude one*100 (F4.2)
    F  1 56-59 F4  b  0-999                 !Magnitude one (end of range).  (F4.2)
    F  1 60-61 I2  99 -2,-1,0,8             !Magnitude one precision
                                            ! Type of magnitude 1
    F  1 62-64 A3  -  '   ',
                      '!  ',                ! error
                      '5. ',                ! error
                      'B  ',                ! body wave magnitude (Mb)
                      'C  ',                ! coda length magnitude
                      'D  ',                ! duration magnitude
                      'L  ',                ! Local
                      'N  ',                ! Nuttli
                      'S  ',                ! Surface wave
                      'SZ ',                ! Surface wave on vertical component
                      'W  '                ! Moment
    F  1 65-67 I3  b  0,1-9,   !Number of observations contributing to magnitude one
                      10-19,20-49,50-99,100-199,200-299,300-399,400-999
                      null  1392982
    F  1 68-70 I3  b  0-99,100-999   !Standard error for magnitude one (F3.2)
    F  1 71-72 I2  99 -2--1   !Precision of standard error for magnitude one
    F  1 73-76 I4  b  1-729   !Geographical region number - (prime estimates)
    F  1 77-79 I3  b  1-52    !Seismic region number - (prime estimates)
    F  1 80-83 I4  b  0,1-9,10-99,100-999,1000-9999  !Number of observations
    F  1 84-87 I4  b  0-9, !Standard deviation of one observation*100 (F4.2)
                      10-99,100-999,1000-9999
    F  1 88-89 I2  99 -2,-1  !Precision of standard deviation of one observation
    F  1 90-93 I4  b  1-9,  !Observations contributing to standard deviation
                      10-99,100-999,1000-9999
    


    Record Format 2: Epicentre Continuation

    R  2
    F  2  1 -2 I2  *  2         !Record category
    F  2  3 -4 I2  -  IR        !Next record category
    F  2  5 -8 I4  -  IY        !Reference year
    F  2  9-10 I2  -  1-12      !Reference month
    F  2 11-14 F4  b  0-99,     !Magnitude two (F4.2)
                      100-199,200-299,300-399,400-499,500-599,
                      600-699,700-799,800-899,900-999
                      null   929008
    F  2 15-18 F4  b  0-999     !Magnitude two (end of range) (F4.2)
    F  2 19-20 I2  99 -2--1,0,8   !Magnitude two precision (=99 for null or for rang
                                    !Type of magnitude two
    F  2 21-23 A3  -  '   ',
                      '!  ',                ! error
                      '5. ',                ! error
                      'B  ',                ! body wave magnitude (Mb)
                      'C  ',                ! coda length magnitude
                      'D  ',                ! duration magnitude
                      'L  ',                ! Local
                      'N  ',                ! Nuttli
                      'S  ',                ! Surface wave
                      'SZ ',                ! Surface wave on vertical component
                      'W  '                 ! Moment
    F  2 24-26 I3  b  0,1-9,       !Number of obs. contributing to magnitude two
                      10-99,100-999
    F  2 27-29 I3  b  0-998,999 !Standard error for magnitude two (F3.2)
                      null  1004963
    F  2 30-31 I2  99 -2,0         !Precision of s.e. for magnitude two
    F  2 32-36 I5  b  0-9,      !Standard error for origin time (F5.3)
                      10-99,100-999,1000-9999,10000-99998,99999
    F  2 37-38 I2  99 -6,-5,-4,-3,-2,-1,0       !Precision of s.e. for origin time
    F  2 39-44 I6  b  0-9,             !Standard error latitude (degrees) (F6.4)
                      10-99,100-999,1000-9999,10000-99999,100000-999998,999999
    F  2 45-46 I2  99 -7,-6,-5,-4,-3,-2,-1,0       !Precision of s.e. for latitude
    F  2 47-52 I6  b  0-9,             !Standard error longitude (degrees) (F6.4)
                      10-99,100-999,1000-9999,10000-99999,100000-999998,999999
    F  2 53-54 I2  99 -7,-6,-5,-4,-3,-2,-1,0       !Precision of s.e. for longitude
    F  2 55-58 I4  b  0-9,             !Standard error for depth (km) (F4.1)
                      10-99,100-999,1000-9998,9999
    F  2 59-60 I2  99 -4,-3,-2,-1,0             !Precision of s.e. for depth
    F  2 61-61 A1  -  ' ',             ! Explosion/effects flag:
                      'C',  ! Collapse of nuclear explosion
                      'D',  ! Damaging natural earthquake
                      'F',  ! Felt natural earthquake
                      'H',  ! Chemical explosion
                      'M',  ! Event associated with mining
                      'N',  ! Nuclear explosion or presumed nuclear explosion
                      'R'   ! Rockburst
    F  2 62-64 I3 b  0-999  !Mantissa of explosion charge size in tons (F3.2)
    F  2 65-66 I2 b  -1-10   !Exponent of explosion charge size
    F  2 67-68 I2 99 -3,-2,-1,0,1,3,5      !Precision of explosion charge size
    F  2 69-71 I3 b  1-9,   !Number of pP-P observations
                     10-99,100-999
    F  2 72-75 I4 b  0-9,  !Std. deviation of 1 pP-P observation F4.2
                     10-99,100-999,1000-9998,9999
    F  2 76-80 I5 b -1500--1,     !Depth from pP-P observations (km) F5.2
                     0-9999,10000-19999,20000-29999,30000-39999,40000-69999,
                     70000-77000
    F  2 81-85 I5 b  0-9,  !Std. error of depth from pP-P observations(km) F5.2
                     10-99,100-999,1000-1999,2000-4999,5000-9999,10000-99999
    F  2 86-87 I2 b  0-12   !Maximum intensity
    F  2 88-88 A1 -  ' ','A'        !Intensity scale
    F  2 89-91 I3 b  0-2,   !Distance in degrees to closest observation
                     3-5,6-9,10-89,90-180
    F  2 92-94 I3 b  0-5,6-9,10-89,90-180  !Degrees to most distant observation
    


    Record Format 3: Epicentre Comment

    R  3
    F  3  1 -2 I2  *  3         !Record category
    F  3  3 -4 I2  -  IR        !Next record category
    F  3  5 -8 I4  -  IY        !Reference year
    F  3  9-10 I2  -  1-12      !Reference month
    F  3 11-12 I2  -  1-28,29,30,31          ! Days
    F  3 13-14 I2  -  0-23          !Hours
    F  3 15-16 I2 -   0-59          !Minutes
    F  3 17-20 I4 -   0-5999,6000-6099        !Seconds (F4.2)
    F  3 21-23 I3 -   1-299         !Agency number
    F  3 24-24 A1 -   AZ            !Prime-estimate flag
    F  3 25-96 A72 -  TX            !Comment
    


    Record Format 4: Epicentre Comment Continuation

    R  4
    F  4  1 -2 I2  *  4         !Record category
    F  4  3 -4 I2  -  IR        !Next record category
    F  4  5 -8 I4  -  IY        !Reference year
    F  4  9-10 I2  -  1-12      !Reference month
    F  4 11-12 I2  -  1,2-4,5-9,10-19,20-50      !Serial number (starting at 1)
    F  4 13-96 A84 -  TX        !Comment text
    


    Record Format 5: Initial Phase

    R  5
    F  5  1 -2 I2  *  5         !Record category
    F  5  3 -4 I2  -  IR        !Next record category
    F  5  5 -8 I4  -  IY        !Reference year
    F  5  9-10 I2  -  1-12      !Reference month
    F  5 11-14 A4  -  AS        !Station code
    F  5 15-18 I4  -  1-3000        !Station number
    F  5 19-19 A1 -  ' ','A'        !Network code
                                    ! A Australia
    F  5 20-20 A1 -  ' ',           !Source code
                     '.',
                     '0',
                     '1',
                     '2',
                     '3',
                     '4',
                     '5',
                     '6',
                     '7',
                     '8',
                     '9',
                     'B',
                     'D',
                     'E',
                     'I',
                     'J',           ! Japan Meteorolgical Agency
                     'L',
                     'M',
                     'S',
                     'T',
                     'U',           ! USA  (NEIS)
                     'W'
    F  5 21-21 A1 -  ' ',           ! Format received code
                     '1',           ! ISC format 1
                     '2',           ! ISC format 2
                     '3',           ! ISC format 3
                     'B',           ! Blacknest format ?
                     'F',           ! ISC P=V format
                     'N',           ! NEIS tape format
                     'U'            ! NEIS PDE
    F  5 22-22 A1 - ' ',            ! Local - Teleseismic flag
                    'L',            ! Local
                    'T'             ! Teleseismic
    F  5 23-25 I3 - 0-359           !Azimuth in degrees from epicentre to station
    F  5 26-30 I5 - 0-18000         !Distance in degrees F5.2
    F  5 31-33 I3 - 1-50            !Number of phases in this observation
    F  5 34-35 I2 - 1-28,29,30,31,32            !Days
    F  5 36-37 I2 - 0-23            !Hours
    F  5 38-39 I2 - 0-59            !Minutes
    F  5 40-43 I4 - 0-5999          !Seconds F4.2
    F  5 44-45 I2 99 -3,-2,-1,0,1,2      !Precision of time
    F  5 46-48 I3 999 0-199      !Operator's ID (numerical): see table at end
    F  5 49-56 A8 -         ' ',    !Operator's ID (characters)
    F  5 57-60 I4 - -999,        ! Operator's residual F4.1
                   -998--100,-99--10,-9--1,0,1-9,10-99,100-999,1000-9998,9999
    F  5 61-63 I3 999 0,       !ISC ID (numerical): null as 999
                 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,
                 20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,
                 40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,
                 60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,
                 80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,
                 100,101,102,103,104,105,106,107,108,109,
                 110,111,112,113,114,115,116,117,118,119,
                 120,121,122,123,124,125,126,127,128,129
    F  5 64-67 I4 - -999,         !ISC residual F4.1
                   -998--100,-99--10,-9--1,0,1-9,10-99,100-999,1000-9998,9999
    F  5 68-68 A1 - ' ',    ! Direction of first motion:
                    '+',    ! Short period compression
                    '-',    ! Short period dilatation
                    '1',    ! Long period compression
                    '2',    ! Long period dilatation
                    '3',
                    '4',
                    '5',
                    '6',
                    '7',
                    '?',
                    'A',    ! Compression on short and long period
                    'B',    ! Compression short period, dilatation long period
                    'C',    ! Compression (period unspecified)
                    'D',    ! Dilatation (period unspecified)
                    'E',    ! East
                    'J',    ! Dilatation short period, compression long period
                    'K',    ! Dilatation on short and long period
                    'N',    ! North
                    'R',
                    'U',
                    'W',    ! West
                    '\',
                    'c'
    F  5 69-69 A1 - ' ',    !Instrument type - component is sometimes reported here
                    'B',    ! broad band
                    'E',    ! East-West component!
                    'H',    ! Hilbert transform
                    'N',    ! North-South component!
                    'S',    ! short period
                    'Z',    ! vertical component!
                    'l'
    F  5 70-70 A1 - ' ',    !Component:
                    'D',    ! Down
                    'E',    ! East
                    'H',    ! Horizontal
                    'L',
                    'N',    ! North
                    'P',
                    'R',
                    'S',    ! South
                    'T',    !
                    'U',    ! Up
                    'W',    ! West
                    'Z'     ! Vertical
    F  5 71-71 A1 - ' ',    ! Sharpness:
                    '2',    ! error
                    '9',    ! error
                    'U',    ! error
                    'e',    ! Emergent
                    'i',    ! Impulsive
                    'l'     ! ??
    F  5 72-72 A1 - ' '                     !Signal-to-noise ratio
    F  5 73-75 I3 b -10--1,             !Log A/T (F3.1)
                    0,1-10,11-20,21-30,31-40,41-50,51-60,61-70,71-80,81-90
    F  5 76-77 I2 99 -5,-1,0           !Precision of log A/T
                    ! -5 ???
                    ! -1 to one tenth
                    !  0 to nearest unit
    F  5 78-81 I4 b 0,1-9,          !Mantissa of amplitude (F4.3)
                    10-99,100-999,1000-9999
    F  5 82-83 I2 b 0,1,2,3,4,5,6,7,8,9    !Exponent of amplitude
    F  5 84-85 I2 99 -2,-1,0,1,2,3     !amplitude units
                    ! 0 amplitude in nanometres
                    ! 3 amplitude in micrometres
                    !   any other values are erronoeous
    F  5 86-89 I4 b  0,1-9,10-99,100-999    !Period in seconds (F4.1)
    F  5 90-91 I2 99  -5,-4,-2,-1,0,1       !Precision of period
    F  5 92-93 I2 b -10--1,           !Magnitude (F2.1)
                     0-9,10-19,20-29,30-39,40-49,50-59,60-69,70-79,80-89,90-99
    


    Record Format 6: Later Phase

    R  6
    F  6  1 -2 I2  *  6         !Record category
    F  6  3 -4 I2  -  IR        !Next record category
    F  6  5 -8 I4  -  IY        !Reference year
    F  6  9-10 I2  -  1-12      !Reference month
    F  6 11-12 I2  -  2,3,4,5,6,7,8,9,10-19,20-29,30-39,40-50  !Phase count
    F  6 13-14 I2  b  0-28,29,30,31,32                  !Days
    F  6 15-16 I2  b  0-23                  !Hours
    F  6 17-18 I2  b  0-59                  !Minutes
    F  6 19-22 I4  b  0-5999                !Seconds (F4.2)
    F  6 23-24 I2  99 -3,-2,-1,0,1,2,3,4    !Precision of time
    F  6 25-27 I3 999 0,         !Operator's ID (numerical)
                 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,
                 20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,
                 40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,
                 60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,
                 80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,
                 100,101,102,103,104,105,106,107,108,109,
                 110,111,112,113,114,115,116,117,118,119
    F  6 28-35 A8  -  ' ',   ! Operator's ID (characters)
    2F  6 36-39 I4  -  -999,             !Operator's residual in seconds (F4.1)
                      -998--100,-99--10,-9--1,0,
                            1-9,10-99,100-999,1000-9998,9999
    F  6 40-42 I3 999 0,      !ISC ID (numerical)
                 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,
                 20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,
                 40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,
                 60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,
                 80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,
                 100,101,102,103,104,105,106,107,108,109,
                 110,111,112,113,114,115,116,117,118,119
    F  6 43-46 I4 9999 -999,            !ISC residual in seconds (F4.1)
                       -998--100,-99--50,-49--10,-9--1,0,
                            1-9,10-49,50-99,100-999,1000-9998
    F  6 47-47 A1  -  ' ',            ! Direction of first motion:
                    '+',    ! Short period compression
                    '-',    ! Short period dilatation
                    '1',    ! Long period compression
                    '2',    ! Long period dilatation
                    'A',    ! Compression on short and long period
                    'B',    ! Compression short period, dilatation long period
                    'C',    ! Compression (period unspecified)
                    'D',    ! Dilatation (period unspecified)
                    'J',    ! Dilatation short period, compression long period
                    'K'     ! Dilatation on short and long period
    F  6 48-48 A1 - ' ',    ! Instrument type:
                    'B',    ! broad band
                    'E',
                    'H',    ! Hilbert transform
                    'N',
                    'S',     ! short period
                    'Z'
    F  6 49-49 A1 - ' ',    !Component:
                    'D',    ! down
                    'E',    ! East
                    'H',
                    'L',
                    'N',    ! North
                    'P',
                    'R',    ! radial
                    'S',    ! South
                    'T',    ! tangential
                    'U',    ! up
                    'W',    ! West
                    'X',    ! vertical
                    'Y',    ! vertical
                    'Z'     ! vertical
    F  6 50-50 A1 - ' ',            !Sharpness:
                    'e',            !   Emergent
                    'i'             !   Impulsive
    F  6 51-51 A1  -  ' '           !Signal-to-noise ratio
    F  6 52-54 I3  b  -10--1,0-90   !Log A/T (F3.1)
    F  6 55-56 I2 99  -1            !Precision of log A/T
    F  6 57-60 I4  b  0-999,        !Mantissa of amplitude in millimicrons (F4.3)
                      1000-1999,2000-2999,3000-3999,4000-4999,5000-5999,
                      6000-6999,7000-7999,8000-8999,9000-9998,9999
    F  6 61-62 I2  b  0,1,2,3,4,5,6,7,8,9,10          !Exponent of amplitude
    F  6 63-64 I2 99  -2,-1,0,1,2,3   !Precision of amplitude
    F  6 65-68 I4  b  0-99,      !Period in seconds (F4.1)
                      100-199,200-499,500-999,1000-9999
    F  6 69-70 I2 99  -2,-1,0          !Precision of period
    F  6 71-72 I2  b  0,          !Magnitude (F2.1)
                      10-19,20-29,30-39,40-49,50-59,60-69,70-79,80-89,90-99
    


    Record Format 7: Phase Comments

    R  7
    F  7  1 -2 I2  *  7         !Record category
    F  7  3 -4 I2  -  IR        !Next record category
    F  7  5 -8 I4  -  IY        !Reference year
    F  7  9-10 I2  -  1-12      !Reference month
    F  7 11-12 I2  -  1-5,6-10,11-20   !Count of comment records for this station
    F  7 13-96 A84 -  TX        !Comment
    


    Format 15: Initial Phase Record - 5 Character Codes

    Format 15 is identical to Format 5, except that the fifth character of the station code is appended after all of the other fields, in position 94


    Record Format 90: Agency

    R 90                        !Agency record
    F 90  1 -2 I2  *  90        !Record category
    F 90  3 -4 I2  -  IR        !Next record category
    F 90  5 -8 I4  -  IY        !Reference year
    F 90  9-10 I2  -  1-12      !Reference month
    F 90 11-13 I3  -  1-999     !Agency number
    F 90 14-19 A6  -  AD        !Agency code
    F 90 20-21 I2  -  0-10      !Record number
    F 90 22-96 A75 -  TX        !Name and address lines
    


    Record Format 91: Station

    R 91                        !Station record
    F 91  1 -2 I2  *  91        !Record category
    F 91  3 -4 I2  -  IR        !Next record category
    F 91  5 -8 I4  -  IY        !Reference year
    F 91  9-10 I2  -  1-12      !Reference month
    F 91 11-14 I4  -  1-9999    !Station number
    F 91 15-19 A5  -  TX        !Station code
    F 91 20-22 A3  -  '   '     !Blank
    F 91 23-40 A18 -  TX        !Station name
    F 91 41-61 A21 -  TX        !Geographical or political region
    F 91 62-63 I2  -  0-90      !Latitude degrees
    F 91 64-65 I2  -  0-59      !Latitude minutes
    F 91 66-68 F3  b  0-599     !Latitude seconds*10
    F 91 69-69 A1  -  'N','S'
    F 91 70-72 I3  -  0-179     !Longitude degrees
    F 91 73-74 I2  -  0-59      !Longitude minute
    F 91 75-77 F3  b  0-599     !Longitude seconds*10
     There were some excessively large values (above 599) in the above field.
     The following values were originally present
      SLN was 700 seconds between 196410 and 196611
      PHC was 900 seconds for 196503
      SVW was 600 seconds between 196710 and 196812
    
    F 91 78-78 A1  -  'E','W'
    F 91 79-82 I4  b  -999--100,-99--1,0-6000  !Height above sea level in metres
    F 91 83-83 A1  -  ' ','W'        !W = for world-wide standard stations
    


    Record Format 99: Null

    Null records occur only near the end of a file. Null records originally padded out files to a multiple of a blocking factor. They have been removed from files on ISC CDs.

    R 99                        !Null record
    F 99  1 -2 I2  *  99        !Record category
    F 99  3 -4 I2  -  IR        !Next record category
    F 99  5 -8 I4  -  IY        !Reference year
    F 99  9-10 I2  -  1-12      !Reference month
    


    Numerical Values for Operator Phase IDs

      0 P       37 SSS     74 PN
      1 PP      38 SCS     75 SN
      2 PPP     39 SKS     76 PGPG
      3 PCP     40 SKKS    77 SGSG
      4 PKP     41 SKKKS   78 LR
      5 PKP2    42 SCSPKP  79 LQ
      6 PKPPKP  43 SKSSKS  80 L
      7 PCPPKP  44 SCSP    81 PHASE81
      8 PS      45 SKSP    82 PHASE82
      9 PPS     46 SCP     83 SPP
     10 PCS     47 SP      84 PHASE84
     11 PKS     48 SKP     85 SPECIAL
     12 PKKS    49 SKKP    86 QM
     13 PCSPKP  50 SKPPKP  87 RM
     14 PKPPKS  51 SSP     88 T
     15 PKPSKS  52 PHASE52 89 T(MAX)
     16 PKKP    53 PHASE53 90 NORTH
     17 3PKP    54 PHASE54 91 SOUTH
     18 PKIKP   55 PHASE55 92 EAST
     19 PKP1    56 PHASE56 93 WEST
     20 PKHKP   57 sPKP2   94 UP
     21 PHASE21 58 pPCP    95 DOWN
     22 PSS     59 pPKP    96 E
     23 PHASE23 60 pP      97 I
     24 PHASE24 61 pPP     98 MAXIMUM
     25 PHASE25 62 sP      99 FINAL
     26 PHASE26 63 sPKP   100 S/SKS
     27 PHASE27 64 sS     102 PX
     28 PHASE28 65 sSS    101 P/PKP
     29 PHASE29 66 sPP    103 X1
     30 PHASE30 67 sPCP   104 X2
     31 PHASE31 68 sSCS   105 SX
     32 PHASE32 69 pPKP2  106 SB1
     33 PHASE33 70 P*     107 SB2
     34 PHASE34 71 S*     108
     35 S       72 PG     109 S/(SKS)
     36 SS      73 SG     110 (S)/SKS
    
    Notes:
    • The interpretations such as PHASE21 imply that the phase identification was sent to ISC as the numeric code 21. We do not have a phase corresponding to this code.
    • S/(SKS) implies that the phase was reported to ISC as S/SKS; we have identified it as an S phase. (S)/SKS indicates identification as an SKS phase.
    • 999 indicates that the phase was not identified.
    • An asterisk preceeding an upper case letter indicates that the letter should be treated as a lower case letter. e.g. for *PP read pP.


    Numerical Values for ISC Phase IDs

      0 P       37 SSS     74 PN
      1 PP      38 SCS     75 SN
      2 PPP     39 SKS     76 PGPG
      3 PCP     40 SKKS    77 SGSG
      4 PKP     41 SKKKS   78 LR
      5 PKP2    42 SCSPKP  79 LQ
      6 PKPPKP  43 SKSSKS  80 L
      7 PCPPKP  44 SCSP    81 PKKP3
      8 PS      45 SKSP    82 PKKS3
      9 PPS     46 SCP     83 SPP
     10 PCS     47 SP      84 PHASE84
     11 PKS     48 SKP     85 P DIFF
     12 PKKS    49 SKKP    86 QM
     13 PCSPKP  50 SKPPKP  87 RM
     14 PKPPKS  51 SSP     88 T
     15 PKPSKS  52 SKP2    89 T(MAX)
     16 PKKP    53 SKS2    90 NORTH
     17 3PKP    54 SKKS2   91 SOUTH
     18 PKIKP   55 SKKS3   92 EAST
     19 PP2     56 SKKKS2  93 WEST
     20 PPP2    57 sPKP2   94 UP
     21 PKS2    58 pPCP    95 DOWN
     22 PSS     59 pPKP    96 E
     23 PSS2    60 pP      97 I
     24 SSP2    61 pPP     98 MAXIMUM
     25 PCPPKP2 62 sP      99 FINAL
     26 PCSPKP2 63 sPKP   100
     27 SS2     64 sS
     28 PKKP2   65 sSS
     29 PKKS2   66 sPP
     30 SCSPKP3 67 sPCP
     31 SCSPKP2 68 sSCS
     32 SCSP2   69 pPKP2
     33 SKSP2   70 P*
     34 SSS2    71 S*
     35 S       72 PG
     36 SS      73 SG
    

    Note: 100 implies no ISC identification.