RFOC-package: Calculates and plot Earthquake Focal Mechanisms

Description

Graphics for statistics on a sphere, as applied to geological fault data, crystallography, earthquake focal mechanisms, radiation patterns, ternary plots and geographical/geological maps. Given strike-dip-rake or a set of fault planes, focal planes, RFOC creates structures for manipulating and plotting earthquake focal mechanisms as individual plots or distributed spatially maps.

RFOC can be used for analysis of plane orientation, geologic structure, distribution of stress and strain analyses.

Arguments

Author

Jonathan M. Lees Maintainer: Jonathan M. Lees <jonathan.lees@unc.edu>

Details

Visualize focal mechanisms in a number of modes, including: beachball plots, radiation plots, fault planes and ternary diagrams. Shows spatial distribution of spherically distributed data.

References

J. M. Lees. Geotouch: Software for three and four dimensional GIS in the earth sciences. Computers and Geosciences , 26(7):751--761, 2000.

K.~Aki and P.~G. Richards.Quantitative seismology. University Science Books, Sausalito, Calif., 2nd edition, 2002.

Snyder, John P., 1987, Map Projections-a working manual, USGS-Professional Paper, 383p.

C. Frohlich. Triangle diagrams: ternary graphs to display similarity and diversity of earthquake focal mechanisms. Physics of the Earth and Planetary Interiors, 75:193-198, 1992.

Examples

Run this code


#############  plot one focal mechanism:
M = SDRfoc(-25, 34, 16,u = FALSE, ALIM = c(-1, -1, +1, +1), PLOT=TRUE)


#############  plot many P-axes:
paz = rnorm(100, mean=297, sd=100)
pdip = rnorm(100, mean=52, sd=20)
net()
focpoint(paz, pdip, col='red',  pch=3, lab="", UP=FALSE)

#############

#### Show many Focal mechanisms on a plot:

Z1 = c(159.33,51.6,206,18,78,
161.89,54.5,257,27,133,
170.03,53.57,-44,13,171,
154.99,50.16,-83,19,-40,
151.09,47.15,123,23,-170,
176.31,51.41,-81,22,122,
153.71,46.63,205,28,59,
178.39,51.21,-77,16,126,
178.27,51.1,-86,15,115,
177.95,51.14,-83,25,126,
178.25,51.18,215,16,27
)

MZ = matrix(Z1, ncol=5, byrow=TRUE)

plot(MZ[,1], MZ[,2], type='n', xlab="LON", ylab="LAT", asp=1)

for(i in 1:length(MZ[,1]))
{
paste(MZ[i,3], MZ[i,4], MZ[i,5])


MEC =  SDRfoc(MZ[i,3], MZ[i,4], MZ[i,5], u=FALSE, ALIM=c(-1,-1, +1, +1), PLOT=FALSE)
fcol =  foc.color(foc.icolor(MEC$rake1), pal=1)
justfocXY(MEC, x=MZ[i,1], y =MZ[i,2] , focsiz=0.5, fcol =fcol , fcolback = "white", xpd = TRUE)


}