Generalities

BeachBalls is a Fortran program, running in a console window, that allows the user to generate vector symbols of earthquake focal mechanisms to be plotted as a MapInfo® table. BeachBalls reads an input file containing the following data: (1) an header line (this can be also an empty line); (2) a series of lines (one for each earthquake) containing an identification number, longitude, latitude, strike, dip, rake, and earthquake magnitude. Format of input data is free. Data values must be separated by blanks or tabs.

The preferred plane of the focal mechanism can be outlined in red by setting the appropriate option when prompted. Size of focal mechanisms is scaled according to earthquake magnitude and to a multiplier set by the user.

The program generates two files, namely "Beach_Balls.mif" and "Beach_Balls.mid", in the MapInfo® Interchange File format. These files must be imported into MapInfo® to generate a mappable table.


Acknowledgements

We thank "grafic@immagini" lab for designing the BeachBalls logo.