grdpmodeler - Evaluate a plate model on a geographic grid
grdpmodeler agegrdfile -Erot_file -Goutgrdfile -Sa|d|r|w|x|y|X|Y [ -Fpolygonfile ] [ -Tage ] [ -V[level] ] [ -b[i|o][ncol][type][w][+L|+B] ] [ -h[i|o][n][+c][+d][+rremark][+rtitle] ] [ -icols[l][sscale][ooffset][,...] ] [ -:[i|o] ]
Note: No space is allowed between the option flag and the associated arguments.
grdpmodeler reads a geographical age grid and a plate motion model and evaluates one of several model predictions. Optionally, the user may supply a clipping polygon in multiple-segment format; then, only the part of the grid inside the polygon is used to determine the model prediction; the remainder of the grid is set to NaN.
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 tstop is not present in the record then a total reconstruction rotation is expected and tstop is implicitly set to 0 and should not be specified for any of the records 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. You may prepend a leading + to the filename to indicate you wish to invert the rotations. Alternatively, give the filename composed of two plate IDs separated by a hyphen (e.g., PAC-MBL) and we will instead extract that rotation from the GPlates rotation database. We return an error if the rotation cannot be found.
We will use a grid with Pacific crust ages (pac_age.nc), a plate motion model (Pac_APM.d), and a polygon that contains the outline of the present Pacific plate (pac_clip_path.d). To evaluate the plate motion azimuths at the present time for the Pacific, try
gmt grdpmodeler pac_age.nc -EPac_APM.d -V -Fpac_clip_path.d \ -Gpac_dir_0.nc -Sa -T0
To determine the changes in latitude since crust formation for the entire Pacific, try
gmt grdpmodeler pac_age.nc -EPac_APM.d -V -Fpac_clip_path.d \ -Gpac_dlat.nc -Sy
To determine the plate motion rates in effect when the Pacific crust was formed, try
gmt grdpmodeler pac_age.nc -EPac_APM.d -V -Fpac_clip_path.d \ -Gpac_vel.nc -Sr
To determine how far the crust has moved since formation, try
gmt grdpmodeler pac_age.nc -EPac_APM.d -V -Fpac_clip_path.d \ -Gpac_dist.nc -Sd
backtracker, grdrotater, grdspotter, hotspotter, originator, rotconverter