I'm drawing earthquakes on the map using QGIS and I need to plot focal mechanism by beach balls. I don't want to use svg because it need to transform new locations on the map.

Is there a plugin or tool that I can use for earthquake problems like this?

  • 3
    What do you mean by "beach ball" in this context? Commented Apr 21, 2017 at 11:17
  • 2
    @bugmenot123 It's an academia geological term aka focal mechanisms for what amounts to a symbol earthquake-report.com/2014/05/17/…
    – risail
    Commented Apr 21, 2017 at 12:13
  • yes . its kind of graphical solution of fault mechanism . you can see it at answers .
    – Soroush
    Commented Apr 21, 2017 at 20:36
  • If you can solve my problem here: gis.stackexchange.com/questions/315393/… Then we can plot 3d focal mechanisms in qgis2threejs. I've grappled about this problem for nights, but I can't find a solution! Commented Mar 13, 2019 at 16:22

2 Answers 2


Apparently it is possible:


A Friedrich Prinz mentioned in a recent Digital Geography post about how he wrote some code to create the beachballs. Although he mentioned he might do some more work on the coding, you could try asking him directly if he could share some of the code.

  • 1
    Shouldn the beach balls be drawn with two dots indicating the P (Pressure) and T (Tension) axis?...
    – Brethlosze
    Commented Apr 6, 2018 at 23:37
  • @hyprfrcb - You could ask that as a comment on the website :)
    – Joseph
    Commented Apr 9, 2018 at 10:09

I went through this same problem a while back and was not able to find a solution with QGIS. The question is asked here on SE focal mechanism(beach balls) for many Earthquakes, at the time I opted to do it with GMT my code is long gone but a quick search nets a few examples of what the data structure and command should look like two examples: http://eqinfo.ucsd.edu/~rnewman/howtos/gmt/tips.php http://geophysics.eas.gatech.edu/people/anewman/classes/Intro_GMT/adv_gmt.html

From the SE post I linked to the google KML looks to be the path of least resistance, you might be able to import the KML you generate into QGIS. As @Joseph has pointed out it seems that a custom solution is out there now, but I do not believe there is a supported plugin for it yet.

  • ok . tanks . all Excellent .
    – Soroush
    Commented Apr 21, 2017 at 20:36

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