The July 8, 1971 Chilean earthquake

Observations on the destructive 1971 Chilean earthquake show that the epicenter and focal mechanism might be different from the one in 1965 in the same region. Field study shows that almost all damage was confined to poorly-built structures or to those that were not earthquake-resistant. Local high intensities are well correlated with the soil characteristics of alluvial valleys. Analyses of accelerograms at Santiago, about 140 km from the epicenter, show, as in 1965, rather high (15 to 17 per cent of g) values of ground accelerations for that distance.