Source parameters of the M-w=6.3 Aroma crustal earthquake of July 24, 2001 (northern Chile), and its aftershock sequence

Abstract

The July 24, 2001, M-w = 6.3 earthquake in Aroma, Chile, is one of the few moderately shallow earthquakes to occur recently in northern Chile. This study uses different seismological data (short-period, broadband, strong-motion) to locate the event and its corresponding aftershocks. In addition, it carefully constrains the focal depth using SP phase and the focal mechanism of the main-shock. Finally, a model of the strong-motion waveforms discriminates the activated fault plane among the two nodal planes. The main-shock fault plane solution obtained from the strong-motion analysis is (strike, dip, rake) = (14 degrees +/- 10 degrees, 53 degrees +/- 15 degrees, -163 degrees +/- 15 degrees), which indicates a rightlateral motion on an inclined fault, in agreement with the aftershock distribution, which also indicates a fault striking N 14 degrees E and dipping about 50 degrees E. (C) 2007 Elsevier Ltd. All rights reserved.