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Radiation pattern from shear-tensile seismic source

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Calculates P, S, SV and SH radiation pattern using shear-tensile seismic source model.

Updated

Function calculates P-wave, S-wave, SH-wave and SV-wave radiation pattern using shear-tensile source model [cf. references 1-3 for details]. All input angles (strike, dip, rake of the fault, tensile angle gamma, takeoff angle TKO and azimuth from the source to the observation point AZM) should be provided in degrees. The takeoff angle is measure from bottom. The azimuth to the observation point is measured from north to east. The function returns matrices of the same size as input TKO and AZM matrices which should be of the same size and denote a set of observation points specified by takeoff angles and azimuth.

[1] Kwiatek, G. and Y. Ben-Zion (2013). Assessment of P and S wave energy radiated from very small shear-tensile seismic events in a deep South African mine. J. Geophys. Res. 118, 3630-3641, doi: 10.1002/jgrb.50274
[2] Ou, G.-B., 2008, Seismological Studies for Tensile Faults. Terrestrial, Atmospheric and Oceanic Sciences 19, 463.
[3] Vavryčuk, V., 2001. Inversion for parameters of tensile earthquakes.” J. Geophys. Res. 106 (B8): 16339–16355. doi: 10.1029/2001JB000372.

Kevin Wang

Michael

Grzegorz Kwiatek

Grzegorz Kwiatek (view profile)

@Michael
Here is a sample script that produces either radiation pattern "flower" or (if you replace scale=abs(GP) with scale=1) something similar to beach ball. Hope it helps!

AZIMUTH = (0:4:360)*pi/180;
TAKEOFF = (0:2:180)*pi/180;
[AZIMUTH,TAKEOFF] = meshgrid(AZIMUTH,TAKEOFF);

strike = 50;
dip = 60;
rake = -90;
sigma = 0.25;
gamma = 0;
[GP, GS, GSH, GSV] = rpgen(strike,dip,rake,gamma,sigma, TAKEOFF*180/pi, AZIMUTH*180/pi);

scale = abs(GP);
YP = scale.*cos(AZIMUTH) .* sin(TAKEOFF);
XP = scale.*sin(AZIMUTH) .* sin(TAKEOFF);
ZP = scale.*-cos(TAKEOFF);

surf(XP,YP,ZP,GP,'EdgeColor','none','FaceAlpha',0.9,'AmbientStrength',0.7,'EdgeColor','k','EdgeAlpha',0.1);
axis equal;

Michael

Michael (view profile)

how I plot the radiation patterns after calculating the coefficients?

MATLAB Release
MATLAB 7.8 (R2009a)