We examine and model analogue recordings from 6 early mechanical seismographs for the 1910 June 16 earthquake at Adra, Southern Spain. Modern standard, time-domain analysis techniques were applied to the historical data to estimate the...
moreWe examine and model analogue recordings from 6 early mechanical seismographs for the 1910 June 16 earthquake at Adra, Southern Spain. Modern standard, time-domain analysis techniques were applied to the historical data to estimate the source parameters of the event: The regional sparse network data were inverted for the deviatoric seismic moment tensor. The best moment tensor solution corresponds to a M0= 1.50 . 1018 Nm, MW 6.1 oblique strike-slip event at 16 km depth. Our preferred faulting solution is: strike 122°, dip 80°, rake -137°, in very good agreement with available neo- and seismotectonic data. The source time function of this earthquake was estimated by deconvolving recordings of a MW 5.5 aftershock that occurred the same day. The time function indicates a total rupture time of 4.5 s, corresponding to estimates for mainshock rupture length of 12 km, and stress drop of 29 bar.