1ORIGINATOR(1)                Generic Mapping Tools               ORIGINATOR(1)
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NAME

6       originator - Associate seamounts with hotspot point sources
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SYNOPSIS

9       originator  [infile(s)]  -Estage_file  -Fhs_file  [  -C  ] [ -Dd_km ] [
10       -H[i][nrec] ] [ -L[flag ] [ -Nupper_age ] [ -Qr/t ] [ -S[n_hs] ] [ -T ]
11       [ -V ]  -Wmaxdist ] [ -:[i|o] ] [ -bi[s|S|d|D[ncol]|c[var1/...]] ]
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DESCRIPTION

14       originator  reads  (longitude,  latitude,  height, radius, crustal_age)
15       records from infiles [or standard input] and uses  the  given  Absolute
16       Plate  Motion  (APM)  stage  poles and the list of hotspot locations to
17       determine the most likely origin (hotspot) for each seamount.  It  does
18       so  by  calculating  flowlines back in time and determining the closest
19       approach to all hotspots.  The output consists  of  the  input  records
20       with  four  additional  fields  added  for  each  of  the  n_hs closest
21       hotspots.  The four fields are the hotspot id (e.g., HWI), the stage id
22       of  the  flowline  segment  that  came  closest,  the pseudo-age of the
23       seamount, and the closest distance to the hotspot (in km).  See  option
24       -:  on  how  to  read  (latitude, longitude,height, radius, crustal_ag)
25       files.
26            No space between the option flag  and  the  associated  arguments.
27       Use upper case for the option flags and lower case for modifiers.
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29       infile(s)
30              Seamount  data  file(s)  to be analyzed.  If not given, standard
31              input is read.
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33       -E     Give file with stage poles and opening angles.  This  file  must
34              contain  one  record  for each stage; each record must be of the
35              following format:
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37                   lon lat tstart tstop ccw-angle
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39              where tstart and tstop are in Ma and the  rest  is  in  degrees.
40              The  oldest  stage  must be listed first.  tstart (tstop) is the
41              age of the old (young)  end  of  the  stage.   Blank  lines  and
42              records whose first column contains # will be ignored.
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44       -F     Give  file  with  hotspot locations.  This file must contain one
45              record for each hotspot to be considered; each record must be of
46              the following format:
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48                   lon lat hs_id hs_name
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50              E.g., for Hawaii this may look like
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52              205  20   HWI  Hawaii
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54              Blank  lines  and  records whose first column contains # will be
55              ignored.
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OPTIONS

58       -C     Expect Total Reconstruction Poles  rather  than  Backward  Stage
59              Poles  [Default].  File format is similar to the stage pole for‐
60              mat except the youngest rotation must be listed first  and  that
61              the tstart column is optional (assumed to be 0 Ma).
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63       -D     Sets the flowline sampling interval in km.  [Default is 5].
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65       -H     Input  file(s)  has  Header record(s).  Number of header records
66              can be changed by editing your .gmtdefaults4 file.  If used, GMT
67              default  is  1  header record. Use -Hi if only input data should
68              have header records [Default will write out  header  records  if
69              the input data have them]. Blank lines and lines starting with #
70              are always skipped.
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72       -L     Output clostest approach for nearest hotspot only (ignores  -S).
73              Choose  -Lt for (time, dist, z) [Default], -Lw for (omega, dist,
74              z), and -Ll for (lon, lat, time, dist, z).  Normally, dist is in
75              km;  use  upper  case  modifiers  TWL  to  get dist in spherical
76              degrees.
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78       -N     Set the maximum age to extend the oldest stage back in time  [no
79              extension].
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81       -Q
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83       INput files only has (x,y,z); specify constant values for r,t that
84              will  be  implied for each record.  -S Set the number of closest
85              hotspots to report [Default is 1].
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87       -T     Truncate seamount ages exceeding the upper age set with  -N  [no
88              truncation].
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90       -V     Selects verbose mode, which will send progress reports to stderr
91              [Default runs "silently"].
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93       -W     Only report those seamounts whose flowlines came within  maxdist
94              to any hotspot [Default reports all seamounts].
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96       -:     Toggles  between  (longitude,latitude)  and (latitude,longitude)
97              input and/or output.  [Default is (longitude,latitude)].  Append
98              i  to  select  input  only or o to select output only.  [Default
99              affects both].
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101       -bi    Selects binary input.  Append s for single precision [Default is
102              d  (double)].   Uppercase  S  or  D  will  force  byte-swapping.
103              Optionally, append ncol, the number of columns  in  your  binary
104              input  file if it exceeds the columns needed by the program.  Or
105              append c  if  the  input  file  is  netCDF.  Optionally,  append
106              var1/var2/...  to specify the variables to be read.  [Default is
107              5 input columns].
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EXAMPLES

110       To find the likely (hotspot) origins of the  seamounts  represented  by
111       the (x,y,z,r,tc) points in the file seamounts.d, using the DC85.d Euler
112       poles and the pac_hs.d list of possible hotspots, and report the 2 most
113       likely hotspot candidates for each seamount, run
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115       originator seamounts.d -S2 -EDC85.d -Fpac_hs.d > origins.d
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SEE ALSO

119       GMT(1), project(1), mapproject(1), backtracker(1) hotspotter(1)
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REFERENCES

122       Wessel,  P.,  1999,  "Hotspotting"  tools  released, EOS Trans. AGU, 80
123       (29), p. 319.
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127GMT 4.3.1                         15 May 2008                    ORIGINATOR(1)
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