originator

       originator   -  Associate  seamounts  with  hotspot  point
       sources

SYNOPSIS

       originator [infile(s)] -Estage_file -Fhs_file  [  -C  ]  [
       -Dd_km  ] [ -H[nrec] ] [ -Nupper_age ] [ -S[n_hs] ] [ -T ]
       [ -V ] -Wmaxdist ] [ -: ] [ -bi[s][n] ]

DESCRIPTION

       originator reads  (longitude,  latitude,  height,  radius,
       crustal_age)  records from infiles [or standard input] and
       uses the given Absolute Plate Motion (APM) stage poles and
       the list of hotspot locations to determine the most likely
       origin (hotspot) for each seamount. It does so  by  calcu­
       lating  flowlines back in time and determining the closest
       approach to all hotspots. The output consists of the input
       records  with four additional fields added for each of the
       n_hs closest hotspots. The four fields are the hotspot  id
       (e.g.,  HWI),  the  stage  id of the flowline segment that
       came closest, the pseudo-age  of  the  seamount,  and  the
       closest distance to the hotspot (in km).  See option -: on
       how   to   read   (latitude,   longitude,height,   radius,
       crustal_ag) files.
               No  space  between the option flag and the associ­
       ated arguments. Use upper case for the  option  flags  and
       lower case for modifiers.

       infile(s)
              Seamount data file(s) to be analyzed. If not given,
              standard input is read.

       -E     Give file with stage poles and opening angles. This
              file  must  contain one record for each stage; each
              record must be of the following format:

                      lon lat tstart tstop ccw-angle

              where time is in Ma and the  rest  is  in  degrees.
              Oldest  stage  must  be listed first. tstart is the
              time when the stage  begins  (oldest  age).   Blank
              lines  and  records  whose  first column contains #
              will be ignored.

       -F     Give file with hotspot locations.  This  file  must
              contain  one  record for each hotspot to be consid­
              ered; each record must be of the following format:

                      lon lat hs_id hs_name

              E.g., for Hawaii this may look like

              205 20 HWI Hawaii
              # will be ignored.

OPTIONS

       -C     Expect  Total  Reconstruction  Poles (Finite Poles)
              rather than Backward  Stage  Poles  [Default]  File
              format  is  similar to the stage pole format except
              the youngest rotation must be listed first and that
              the tstart column is optional (assumed to be 0 Ma).

       -D     Sets the flowline sampling interval in km. [5].

       -H     Input  file(s)  has  Header  record(s).  Number  of
              header records can be changed by editing your .gmt­
              defaults file. If used, GMT  default  is  1  header
              record.

       -N     Set the maximum age to extend the oldest stage back
              in time [no extension].

       -S     Set the number of closest hotspots to report [1].

       -T     Truncate seamount ages exceeding the upper age  set
              with -N [no truncation].

       -V     Selects  verbose  mode,  which  will  send progress
              reports to stderr [Default runs "silently"].

       -W     Only report those seamounts whose flowlines'  clos­
              est approach to any hotspot' were less than maxdist
              [Default reports all seamounts].

       -:     Toggles  between  (longitude,latitude)  and  (lati­
              tude,longitude)  input/output.  [Default is (longi­
              tude,latitude)].  Applies to geographic coordinates
              only.

       -bi    Selects binary input. Append s for single precision
              [Default is double].  Append n for  the  number  of
              columns in the binary file(s).  [Default is 5 input
              columns]

EXAMPLES

       To find the likely (hotspot) origins of the seamounts rep­
       resented   by   the   (x,y,z,r,tc)   points  in  the  file
       seamounts.d, using the DC85.d Euler poles and the pac_hs.d
       list  of  possible  hotspots, and report the 2 most likely
       hotspot canditates for each seamount, run

       originator seamounts.d -S2 -EDC85.d -Fpac_hs.d > origins.d

SEE ALSO

REFERENCES

       Wessel, P., 1999, "Hotspotting" tools released, EOS Trans.
       AGU, 80 (29), p. 319.