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building codes

Earthquakes do not kill people. Buildings, landslides and fires do. That distinction, unglamorous as it is, explains almost the entire variation in death tolls between seismically similar events in different countries. A magnitude 7 beneath a city with enforced modern codes produces dozens of deaths. The same magnitude beneath a city of unreinforced masonry produces tens of thousands.

• Base isolation: bearings between foundation and structure that let the ground move while the building stays comparatively still. Standard for Japanese hospitals and data centres.
• Ductile detailing: reinforcement designed so concrete members bend and absorb energy rather than shearing. Cheap at construction, impossible to retrofit affordably.
• Tuned mass dampers: large counterweights in tall buildings that oppose sway.
• Soft-storey retrofits: bracing the open ground floors — shops, parking — that collapse first and bring everything above down with them.