Observations of the 1989 Loma Prieta earthquake

  • Peter Marks Wellington city Council, Wellington, New Zealand


This report has been modified from one presented to the Wellington City Council and sets out observations and conclusions gained from a visit to San Francisco and the area affected by the Loma Prieta Earthquake which struck the San Francisco Bay area on 17 October 1989. I visited the area from 29 November to 8 December 1989.

The earthquake occurred at 5.04pm local time and was measured at 7.1 on the Richter scale. It was located 16km NE of Santa Cruz and 30km south of San Jose in the Santa Cruz mountains, 100 km south of San Francisco City. Sixty two people were killed, 994 homes destroyed with 18,000 not occupiable immediately after the earthquake. 155 businesses were destroyed and 2,500 businesses closed temporarily. Cost of damage is estimated at between 6.5 and 10 billion US dollars. San Francisco City suffered a major visitor decline after the earthquake.

I attended as one of three members of the New Zealand National Society for Earthquake Engineering "Follow Up" Reconnaissance team for the purpose of establishing what damage had occurred to sewer and stormwater systems, water supply systems and gas utilities. My visit was funded by the Wellington City Council and was mostly devoted to study of sewer and stormwater systems.

How to Cite
Marks, P. (1990). Observations of the 1989 Loma Prieta earthquake. Bulletin of the New Zealand Society for Earthquake Engineering, 23(4), 235-238. https://doi.org/10.5459/bnzsee.23.4.235-238