Kobe and Northridge Two earthquakes compared

Abstract

The earthquakes striking Northridge, California in 1994 and Kobe, Japan just a year later highlighted the vulnerability of modern cities to natural hazards. The Northridge quake affected a suburban area, consisting of a mixture of residential and commercial districts but having no industrial plants of any great size. In Kobe, by contrast, the entire urban area, having a high concentration of population and buildings in the city centre, major industrial plants, and a large port area, was hit. This fact, and the higher price levels in Japan, explain why the extent of the losses in Kobe was significantly higher. The Kobe tremor demonstrated that much more attention must be paid in future to reinforcing important older buildings or buildings that are especially at risk. The fact that many modern high rise buildings survived intact showed that it is possible to design earthquake resistant structures, although the safety of steel frame structures, hitherto thought to be good, is now more questionable. Theories predicting that a similar event in a conurbation such as San Francisco or Tokyo–Yokohama could affect the entire world economy must now be viewed as having greater credibility.