Many lives and millions of dollars have already been saved by this ongoing research. The Transamerica Pyramid in San Francisco, built to withstand earthquakes, swayed more than 1 foot but was not damaged in the 1989 Loma Prieta, California, earthquake. Sixty miles away, in downtown San Francisco, the occupants of the Transamerica Pyramid were unnerved as the 49-story office building shook for more than a minute. However, no one was seriously injured, and the Transamerica Pyramid was not damaged. This famous San Francisco landmark had been designed to withstand even greater earthquake stresses, and that design worked as planned during the earthquake.
Earthquakes are a widespread hazard in the United States.
The U.S. Geological Survey operates instruments in many structures in the seismically active areas shown. These instruments measure how structures respond to earthquake shaking. Designing and building large structures is always a challenge, and that challenge is compounded when they are built in earthquake-prone areas. As earth scientists learn more about ground motion during earthquakes and structural engineers use this information to design stronger buildings, such loss of life and property can be reduced. To design structures that can withstand earthquakes, engineers must understand the stresses caused by shaking.