Geodetic observations of the M 5.1 January 29, 1994 Northridge aftershock

Geodetic observations of the January 29, 1994 M 5.1 aftershock of the Northridge earthquake are consistent with seismic solutions Showing left-lateral Oblique slip on a northeast striking steeply dipping fault. Thirty second solutions of the data from the station showing the maximum observed displacement (35 mm) indicate neither precursory nor immediate post-seismic motion to the aftershock. The aftershock does appear to be superimposed over the longer term Northridge post-seismic deformation field. Inversions of the data yield a potency of 2.6 +/- 0.3 x 10(-3) km(3) slightly higher than that determined by seismic methods. Combining the potency with estimates of rigidity from P- and S-wave velocities yields a moment that is consistent with seismic moment solutions.