HOTSPOTTER(1) Generic Mapping Tools HOTSPOTTER(1)NAMEhotspotter - Create CVA image from seamount flowlines
SYNOPSIShotspotter [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/...]] ]
DESCRIPTIONhotspotter 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 Ampli‐
tude 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 rota‐
tion 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 nauti‐
cal miles, respectively, and will be converted to the equivalent
degrees longitude at the middle latitude of the region (the con‐
version 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 fac‐
tors gives higher resolutions at the expense of longer process‐
ing 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 maxi‐
mum.
-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 --ELLIP‐
SOID=sphere.
SEE ALSOGMT(1), grdimage(1), grdrotater(1), grdspotter(1), project(1), mappro‐
ject(1), backtracker(1), originator(1)REFERENCES
Wessel, P., 1999, "Hotspotting" tools released, EOS Trans. AGU, 80
(29), p. 319.
GMT 4.5.14 1 Nov 2015 HOTSPOTTER(1)
