Provided by: gmt_4.5.11-1build1_amd64 
NAME
hotspotter - Create CVA image from seamount flowlines
SYNOPSIS
hotspotter [infile(s)] -Estage_file -GCVAgrid -Ixinc[unit][=|+][/yinc[unit][=|+]]
-Rwest/east/south/north[r] [ -C ] [ -Dfactor ] [ -F ] [ -H[i][nrec] ] [ -Nupper_age ] [ -S
] [ -T ] [ -V ] [ -:[i|o] ] [ -bi[s|S|d|D[ncol]|c[var1/...]] ]
DESCRIPTION
hotspotter reads (longitude, latitude, amplitude, radius, age) records from infiles [or
standard input] and calculates flowlines using the specified stage pole (Euler) rotations.
These flowlines are convolved with the shape of the seamount (using a Gaussian shape given
amplitude and radius = 6 sigma) and added up to give a Cumulative Volcano Amplitude grid
(CVA). See option -: on how to read (latitude,longitude,...) 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)
Data file(s) to be processed. If not given, standard input is read.
-E Give file with rotation parameters. This file must contain one record for each
rotation; each record must be of the following format:
lon lat tstart [tstop] angle [ khat a b c d e f g df ]
where tstart and tstop are in Myr and lon lat angle are in degrees. tstart and
tstop are the ages of the old and young ends of a stage. If -C is set then a total
reconstruction rotation is expected and tstop is implicitly set to 0 and should not
be specified in the file. If a covariance matrix C for the rotation is available
it must be specified in a format using the nine optional terms listed in brackets.
Here, C = (g/khat)*[ a b d; b c e; d e f ] which shows C made up of three row
vectors. If the degrees of freedom (df) in fitting the rotation is 0 or not given
it is set to 10000. Blank lines and records whose first column contains # will be
ignored.
-G Specify name for output grid file.
-I x_inc [and optionally y_inc] is the grid spacing. Optionally, append a suffix
modifier. Geographical (degrees) coordinates: Append m to indicate arc minutes or
c to indicate arc seconds. If one of the units e, k, i, or n is appended instead,
the increment is assumed to be given in meter, km, miles, or nautical miles,
respectively, and will be converted to the equivalent degrees longitude at the
middle latitude of the region (the conversion depends on ELLIPSOID). If /y_inc is
given but set to 0 it will be reset equal to x_inc; otherwise it will be converted
to degrees latitude. All coordinates: If = is appended then the corresponding max
x (east) or y (north) may be slightly adjusted to fit exactly the given increment
[by default the increment may be adjusted slightly to fit the given domain].
Finally, instead of giving an increment you may specify the number of nodes desired
by appending + to the supplied integer argument; the increment is then recalculated
from the number of nodes and the domain. The resulting increment value depends on
whether you have selected a gridline-registered or pixel-registered grid; see
Appendix B for details. Note: if -Rgrdfile is used then grid spacing has already
been initialized; use -I to override the values.
-R west, east, south, and north specify the Region of interest, and you may specify
them in decimal degrees or in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if
lower left and upper right map coordinates are given instead of w/e/s/n. The two
shorthands -Rg and -Rd stand for global domain (0/360 and -180/+180 in longitude
respectively, with -90/+90 in latitude). Alternatively, specify the name of an
existing grid file and the -R settings (and grid spacing, if applicable) are copied
from the grid.
OPTIONS
-C Expect Total Reconstruction Rotations rather than Forward Stage Rotations
[Default]. File format is similar to the stage pole format except that the tstart
column is not present (assumed to be 0 Ma).
-D Modify the sampling interval along flowlines. Default [0.5] gives approximately 2
points within each grid box. Smaller factors gives higher resolutions at the
expense of longer processing time.
-F Force pixel registration [Default is grid registration].
-H Input file(s) has header record(s). If used, the default number of header records
is N_HEADER_RECS. Use -Hi if only input data should have header records [Default
will write out header records if the input data have them]. Blank lines and lines
starting with # are always skipped.
-N Set the upper age to assign seamounts whose crustal age is unknown (i.e., NaN) [no
upper age].
-S Normalize the resulting CVA grid to percentages of the CVA maximum.
-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"].
-: Toggles between (longitude,latitude) and (latitude,longitude) input and/or output.
[Default is (longitude,latitude)]. Append i to select input only or o to select
output only. [Default affects both].
-bi Selects binary input. Append s for single precision [Default is d (double)].
Uppercase S or D will force byte-swapping. Optionally, append ncol, the number of
columns in your binary input file if it exceeds the columns needed by the program.
Or append c if the input file is netCDF. Optionally, append var1/var2/... to
specify the variables to be read. [Default is 5 input columns].
EXAMPLES
To create a CVA image from the Pacific (x,y,z,r,t) data in the file seamounts.d, using the
DC85.d Euler poles, run
hotspotter seamounts.d -E DC85.d -G CVA.grd -R 130/260/-66/60 -I 10m -N 145 -T -V
This file can then be plotted with grdimage.
COORDINATES
Data coordinates are assumed to be geodetic and will automatically be converted to
geocentric before spherical rotations are performed. We convert back to geodetic
coordinates for output. Note: If your data already are geocentric, you can avoid the
conversion by using --ELLIPSOID=sphere.
SEE ALSO
GMT(1), grdimage(1), grdrotater(1), grdspotter(1), project(1), mapproject(1),
backtracker(1), originator(1)
REFERENCES
Wessel, P., 1999, "Hotspotting" tools released, EOS Trans. AGU, 80 (29), p. 319.