Spectral characteristics and source parameters of microearthquakes from the Mt Cameroon volcanic region, West Africa

Abstract

Estimates of source parameters (seismic moment, source radius and stress drop) for a representative sample of 33 Mt Cameroon region microearthquakes, with magnitudes in the range MD= 0.8–2.8, have been obtained from the analysis of their far‐field displacement amplitude spectra. The spectral character of these events seems to be characterized by a lack of high frequencies. The computed seismic moments lie between 1011 and 1011 N m and vary linearly with magnitude, albeit with some scatter. Source radii are relatively large, in the range 135‐703 m. The stress drops are small (0.4‐19 bar) and roughly constant, independent of seismic moment, thus suggesting that the property of self‐similarity seems to hold over this moment range for this area. Copyright © 1991, Wiley Blackwell. All rights reserved