The disaster is known as both as the San Francisco-Oakland earthquake and the Loma Prieta earthquake because it was centered near Loma Prieta Peak in the Santa Cruz Mountains.

An analysis of 745 aftershocks of the M7.1 Loma Prieta earthquake of 17 October, 1989 reveals a wide variety of focal mechansims.At the northwestern end of the aftershock zone earthquakes that apparently occurred off the main rupture plane exhibit mechanisms with predominantly reverse slip on planes nearly parallel to the San Andreas fault.

An eyewitness account describes the experience shared by thousands of San Franciscans working downtown on Oct. 17, 1989, the day the Loma Prieta earthquake struck San Francisco. Loma Prieta Earthquake, Oct 17, 1989 The California government had mandated that all businesses with 200+ employees had to submit an Earthquake Preparedness Plan by Oct 15th, 1989.

Remembering The Deadly 1989 Loma Prieta Earthquake For others, memories of the 2014 Napa Quake also flooded into their rattled minds. The number of aftershocks and their magnitudes after the Loma Prieta earthquake are roughly typical for earthquakes in California. The diverse aftershock sequence of the 1989 Loma Prieta earthquake is inconsistent with conventional models of mainshock-aftershock interaction because the aftershocks do not accommodate mainshock-induced stress changes. Based on statistical studies of average California aftershock sequences, the USGS estimated that there was a 12 percent chance of an aftershock of magnitude 6 or greater in the two months following October 21, 1989. I was the Telecom Manager where I worked and had to be involved in the process, so had been to several vendor presentations relating to planning for a 'big one' .