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.
GMT 4.5.11 5 Nov 2013 HOTSPOTTER(1gmt)