.. index:: ! hotspotter
.. include:: ../module_supplements_purpose.rst_

**********
hotspotter
**********

|hotspotter_purpose|

Synopsis
--------

.. include:: ../../common_SYN_OPTs.rst_

**gmt hotspotter** [*table*]
|-E|\ *rot_file*\|\ *ID1-ID2*\|\ *lon*/*lat*/*angle*\ [**+i**]
|-G|\ *outgrid*
|SYN_OPT-I|
|SYN_OPT-R|
[ |-N|\ *upper_age* ]
[ |-S| ] [ |-T| ]
[ |SYN_OPT-V| ]
[ |SYN_OPT-bi| ]
[ |SYN_OPT-di| ]
[ |SYN_OPT-e| ]
[ |SYN_OPT-g| ]
[ |SYN_OPT-h| ]
[ |SYN_OPT-i| ]
[ |SYN_OPT-o| ]
[ |SYN_OPT-qi| ]
[ |SYN_OPT-r| ]
[ |SYN_OPT-:| ]
[ |SYN_OPT--| ]

|No-spaces|

Description
-----------

**hotspotter** reads (longitude, latitude, amplitude, radius, age)
records from *table* [or standard input] and calculates flowlines
using the specified stage or total reconstruction 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 [*Wessel*, 1999; 2008].

Required Arguments
------------------

.. |Add_intables| unicode:: 0x20 .. just an invisible code
.. include:: ../../explain_intables.rst_

.. include:: explain_rots.rst_

.. _-G:

.. |Add_outgrid| replace::  Specify name for output grid file.
.. include:: /explain_grd_inout.rst_
    :start-after: outgrid-syntax-begins
    :end-before: outgrid-syntax-ends

.. _-I:

.. include:: ../../explain_-I.rst_

.. _-R:

.. |Add_-Rgeo| unicode:: 0x20 .. just an invisible code
.. include:: ../../explain_-Rgeo.rst_

Optional Arguments
------------------

.. _-D:

**-D**\ *factor*
    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.

.. _-N:

**-N**\ *upper_age*
    Set the upper age to assign seamounts whose crustal age is unknown
    (i.e., NaN) [no upper age].

.. _-S:

**-S**
    Normalize the resulting CVA grid to percentages of the CVA maximum.

.. _-T:

**-T**
    Truncate seamount ages exceeding the upper age set with |-N| [no
    truncation].

.. |Add_-V| replace:: |Add_-V_links|
.. include:: /explain_-V.rst_
    :start-after: **Syntax**
    :end-before: **Description**

.. |Add_-bi| replace:: [Default is 5 input columns].
.. include:: ../../explain_-bi.rst_

.. |Add_-di| unicode:: 0x20 .. just an invisible code
.. include:: ../../explain_-di.rst_

.. |Add_-e| unicode:: 0x20 .. just an invisible code
.. include:: ../../explain_-e.rst_

.. |Add_-h| unicode:: 0x20 .. just an invisible code
.. include:: ../../explain_-h.rst_

.. include:: ../../explain_-icols.rst_
.. include:: ../../explain_-ocols.rst_
.. include:: ../../explain_-qi.rst_

.. |Add_nodereg| unicode:: 0x20 .. just an invisible code
.. include:: ../../explain_nodereg.rst_

.. include:: ../../explain_colon.rst_
.. include:: ../../explain_help.rst_

.. include:: explain_geodetic.rst_

Examples
--------

To create a CVA image from the Pacific (*x, y, z, r, t*) data in the file
seamounts.txt, using the DC85.txt Euler poles, run

::

  gmt hotspotter seamounts.txt -EDC85.txt -GCVA.nc -R130/260/-66/60 -I10m -N145 -T -V

This file can then be plotted with :doc:`grdimage </grdimage>`.

Notes
-----

GMT distributes the EarthByte rotation model Global_EarthByte_230-0Ma_GK07_AREPS.rot.
To use an alternate rotation file, create an environmental parameters named
**GPLATES_ROTATIONS** that points to an alternate rotation file.

See Also
--------

:doc:`gmt </gmt>`, :doc:`grdimage </grdimage>`,
:doc:`grdrotater`,
:doc:`grdspotter`,
:doc:`project </project>`,
:doc:`mapproject </mapproject>`,
:doc:`backtracker`,
:doc:`gmtpmodeler`,
:doc:`grdpmodeler`,
:doc:`grdrotater`,
:doc:`originater`

References
----------

Wessel, P., 1999, "Hotspotting" tools released, EOS Trans. AGU, 80 (29), p. 319.

Wessel, P., 2008, Hotspotting: Principles and properties of a plate
tectonic Hough transform, Geochem. Geophys. Geosyst. 9(Q08004):
https://doi.org/10.1029/2008GC002058.
