NAME

     originator - Associate seamounts with hotspot point sources


SYNOPSIS

     originator [infile(s)] -Estage_file  -FEhs_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 calculat-
     ing  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  associated
     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  con-
          tain one record for each hotspot to be considered; 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

          Blank lines and records whose first column  contains  #
          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 .gmtdefaults
          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'  closest
          approach to any hotspot were less than maxdist [Default
          reports all seamounts].

     -:   Toggles      between      (longitude,latitude)      and
          (latitude,longitude)    input/output.     [Default   is
          (longitude,latitude)].

     -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
     represented   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

     gmt(l),    project(l),     mapproject(l),     backtracker(l)
     hotspotter(l)


REFERENCES

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