Rupture Directivity of Moderate Earthquakes
Illustration of the azimuthal variability of the source time function for unilateral rupture faulting. In the moment tensor solution, the beach ball has two theoretical fault planes, the real and the auxiliary fault plane.
Inverted source time functions (a and c) and radiation patterns of normalized energy (b and d) for EQ1 (a and b) and EQ2 (c and d) with Vr = 2.75 km/s. The black and grey vertical arrows represent the theoretical duration of the source-time functions
Radiation patterns of normalized energy with respect to the rupture models and velocity perturbations. The black bold line represents the mean values, and the grey area represents 2 standard deviations with confidence of 95.45%
References
Seung-Hoon Yoo and Junkee Rhie (2009), A new waveform inversion method to determine the rupture directivity of moderate earthquakes: numerical tests for rupture models, Exploration Geophysics, 40, 114-120. [PDF]