Electronic Supplement to
Source Parameters and Tectonic Implications of Aftershocks of the Mw 7.6 Bhuj Earthquake of 26 January 2001

by Paul Bodin and Steve Horton

Bhuj Aftershock Source Parameters

Source parameters of Bhuj aftershocks recorded by the CERI temporary deployment. Not all events recorded are included. Origin time is rounded to nearest second. Depth is in km, positive downward, relative to sea level. Mr is a provisional earthquake size (named for its champion, Ivan Rabak), not a well-defined magnitude scale; it is calculated from the ensemble average of the log of the rms amplitude of the vector sum of the three velocity components at each station in a 2-second time window around both the P and S arrivals. This value is then scaled linearly such that the value for the larger, globally located, earthquakes matches, on average, the body-wave magnitude reported by the U.S. Geological Survey in the Preliminary Determination of Epicenters. RMS is the rms travel-time residual, in seconds for the Hypoellipse location solution, with station corrections applied. The remaining columns are components of the first-motion fault plane solution P1S,D,&R are the strike, dip, and rake of the first nodal plane, P2S,D,&R are the same for the second nodal plane. P-az and P-pl are the azimuth and plunge of the P-axis, and T-az and T-pl the same for the T-axis.